The reaction of carbon-free oxide-based(corundum,spinel,zirconia,and mullite)submerged entry nozzle(SEN)lining with rare earth inclusions and its anti-clogging effects under near working conditions were systematically...The reaction of carbon-free oxide-based(corundum,spinel,zirconia,and mullite)submerged entry nozzle(SEN)lining with rare earth inclusions and its anti-clogging effects under near working conditions were systematically studied.A variety of lining composite test methods were innovatively used to ensure the consistency of test conditions.The experimental results showed that the mullite(acidic oxide)has strong reactivity with rare earth inclusions,and the spinel(basic oxide)has stable chemical properties and weak reactivity with rare earth inclusions.Because alumina is one of the main reactants of clogging formation,corundum is not suitable for SEN lining.There are less clogs on the surface of zirconia,but it will be exsoluted and unstable.Therefore,solving the problem of zirconia exsolution will greatly strengthen its application in SEN lining.展开更多
In this paper,we study the transonic shock solutions to the steady Euler system in a quasi-one-dimensional divergent-convergent nozzle.For a given physical supersonic inflow at the entrance,we obtain exactly two non-i...In this paper,we study the transonic shock solutions to the steady Euler system in a quasi-one-dimensional divergent-convergent nozzle.For a given physical supersonic inflow at the entrance,we obtain exactly two non-isentropic transonic shock solutions for the exit pressure lying in a suitable range.In addition,we establish the monotonicity between the location of the transonic shock and the pressure downstream.展开更多
The performance of a water jet propulsion system is related to the inlet duct,rotor,stator,and nozzle.Generally,the flow inlet design must fit the bottom line of the hull,and the design of the inlet duct is often limi...The performance of a water jet propulsion system is related to the inlet duct,rotor,stator,and nozzle.Generally,the flow inlet design must fit the bottom line of the hull,and the design of the inlet duct is often limited by stern space.The entire section,from the rotor to the nozzle through the stator,must be designed based on system integration in that the individual performance of these three components will influence each other.Particularly,the section from the rotor to the nozzle significantly impacts the performance of a water jet propulsion system.This study focused on nozzle design and established referable analysis results to facilitate subsequent integrated studies on the design parameters regarding nozzle contour.Most existing studies concentrate on discussions on rotor design and the tip leakage flow of rotors or have replaced the existing complex computational domain with a simple flow field.However,research has yet to implement an integrated,optimal design of the section from the rotor to the nozzle.Given the above,our program conducted preliminary research on this system integration design issue,discussed the optimal nozzle for this section in-depth,and proposed design suggestions based on the findings.This program used an existing model as the design case.This study referred to the actual trial data as the design conditions for the proposed model.Unlike prior references’simple flow field form,this study added a jet ski geometry and free surface to the computational domain.After the linear hull shape was considered,the inflow in the inlet duct would be closer to the actual condition.Based on the numerical calculation result,this study recommends that the optimal nozzle outlet area should be 37%of the inlet area and that the nozzle contour should be linear.Furthermore,for the pump head,static pressure had a more significant impact than dynamic pressure.展开更多
In this study, numerical analysis is performed to adopt the equivalence ratio on the high velocity oxygen fuel （HVOF） thermal spray coating systems equipped with a minimum length nozzle. The analysis is applied to i...In this study, numerical analysis is performed to adopt the equivalence ratio on the high velocity oxygen fuel （HVOF） thermal spray coating systems equipped with a minimum length nozzle. The analysis is applied to investigate the axisymmetric, steady-state, turbulent, and chemically combusting flow both within the torch and in a free jet region between the torch and the substrate to be coated. The combustion is modeled using a single-step and eddy-dissipation model which assumes that the reaction rate is limited by the turbulent mixing rate of the fuel and oxidant. As the diameter of the nozzle throat is increased, the location of the Mach shock disc moves backward from the nozzle exit. As the throat diameter and the divergent portion are 6 mm and 8 mm, respectively, the pressure in the HVOF system is the lowest at the chamber and the expanding gas is steadily maintained with both high velocity and high temperature for different equivalence ratios. Thus, relatively minor amendments of the equivalence ratio and the geometry of HVOF can lead to improved control over coating characteristics.展开更多
In order to analyze the spray characteristics of non-circular nozzle holes based on the air-assisted spray system, the spray characteristics of circular and non-circular nozzles were studied under the pressure of 0.2-...In order to analyze the spray characteristics of non-circular nozzle holes based on the air-assisted spray system, the spray characteristics of circular and non-circular nozzles were studied under the pressure of 0.2-0.6 MPa and the spray volume of 1000-5000 mL/h. Elliptical nozzle and triangular nozzle are classified as non-circular geometries. The spray cone angle was measured by processing the spray image captured by a CCD camera. The measured spray cone angles of the circular nozzles were analyzed, and the axis switching phenomenon of minor plane of elliptical nozzle was found during the test. Among the three shapes of nozzles, the elliptical nozzle had the largest spray cone angle, and the triangular nozzle had the smallest. The velocity field obtained depended on the PIV system. The results show that for axial velocity, elliptical orifice spray has greater kinetic energy and smaller droplet size under the same working parameters. Compared with the circular and elliptical nozzles, triangular orifice reached maximum spray velocity the fastest, but its velocity decay was the fastest. For radial velocity, away from the axis, the spray velocity of the elliptical orifice was less affected by the injection parameters, and the velocity was less than that of circular orifice and triangle orifice. Increasing air pressure will weaken radial propagation. The increase of liquid spraying rate had no remarkable effect on the increase of spraying rate. The results of particle size analysis show that the particle size of the non-circular orifice is reduced compared with that of the circular orifice, which promotes the breakup of droplets to a certain extent and enhances the atomization effect.展开更多
Non-metallic inclusions in steel are a significant challenge,affecting material properties and leading to issues such as stress concentration,cracking,and accelerated corrosion.Current methods for removing inclusions,...Non-metallic inclusions in steel are a significant challenge,affecting material properties and leading to issues such as stress concentration,cracking,and accelerated corrosion.Current methods for removing inclusions,including bubble,electromagnetic stirring,filtration separation,fluid flow,and sedimentation,often struggle with the removal of fine inclusions.Apart from these known methods,pulsed electric current(PEC),as an emerging technology,has demonstrated immense potential and environmental advantages.PEC offers adjustable current parameters and simple equipment,making it an attractive alternative to traditional methods.Its green energy-saving features and excellent results in regulating inclusion morphology and migration,as well as inhibiting submerged entry nozzle(SEN)clogging,make it a promising technology.In comparison to continuous current technology,PEC has shown significant advantages in regulating inclusions,not only improving purification efficiency but also demonstrating outstanding performance in flow stability and energy consumption.The ability of PEC to efficiently reduce inclusion numbers enhances the purity and quality of molten steel,improving its mechanical properties.Currently,the theoretical basis for controlling the movement of inclusions by current is mainly composed of three major theories:the double electric layer theory,electromagnetic force reverse separation theory,and electric free energy drive theory.These theories together form an important framework for researchers to understand and optimize the behavior of impurity movement controlled by electric current.Looking ahead,PEC is expected to pave the way for new solutions in directional regulation of inclusion migration,efficient inclusion removal,SEN clogging prevention,and the purification of molten steel.展开更多
Ultra-precision components have been widely used to produce advanced optoelectronic equipment.The so-called Electric field enhanced UltraViolet-Induced Jet Machining(EUV-INCJM)is an ultra-precision method that can ach...Ultra-precision components have been widely used to produce advanced optoelectronic equipment.The so-called Electric field enhanced UltraViolet-Induced Jet Machining(EUV-INCJM)is an ultra-precision method that can achieve sub-nanometer level surface quality polishing.This study focuses on the application of the EUV-INCJM with different nozzle structures to a single-crystal of silicon.Two kinds of electro-optic-liquid coupling nozzles with single-jet and multi-jet focusing structures are proposed accordingly.Simulations and experiments have been conducted to verify the material removal performance of these nozzles.The simulation results show that,under the same condition,the flow velocity of the single-jet nozzle is 1.05 times higher than that achieved with the multi-jet configuration,while the current density of the latter is 1.63 times higher than that of the single-jet nozzle.For the single-crystal silicon,the material removal efficiency of the multi-jet focusing nozzle exceeds by about 1.4 times that of the single-jet.These results confirm that the material removal ability of the multi-jet configuration is more suitable for ultra-smooth surface polishing.The surface roughness of Si workpiece was reduced from Rq 1.55 to Rq 0.816 nm with valleys and peaks on its surface being almost completely removed.展开更多
This paper mainly studies the well-posedness of steady incompressible impinging jet flow problem through a 3D axisymmetric finitely long nozzle.This problem originates from the physical phenomena encountered in practi...This paper mainly studies the well-posedness of steady incompressible impinging jet flow problem through a 3D axisymmetric finitely long nozzle.This problem originates from the physical phenomena encountered in practical engineering fields,such as in short take-off and vertical landing(STOVL)aircraft.Nowadays many intricate phenomena associated with impinging jet flows remain inadequately elucidated,which limits the ability to optimize aircraft design.Given a boundary condition in the inlet,the impinging jet problem is transformed into a Bernoulli-type free boundary problem according to the stream function.Then the variational method is used to study the corresponding variational problem with one parameter,thereby the wellposedness is established.The main conclusion is as follows.For a 3D axisymmetric finitely long nozzle and an infinitely long vertical wall,given an axial velocity in the inlet of nozzle,there exists a unique smooth incom‑pressible impinging jet flow such that the free boundary initiates smoothly at the endpoint of the nozzle and extends to infinity along the vertical wall at far fields.The key point is to investigate the regularity of the corner where the nozzle and the vertical axis intersect.展开更多
Hydraulic sandblasting perforation plays a crucial role in the fracturing and reconstruction of unconventional oil and gas reservoirs.The jet nozzle is an essential part of the hydraulic perforation tool.Insufficient ...Hydraulic sandblasting perforation plays a crucial role in the fracturing and reconstruction of unconventional oil and gas reservoirs.The jet nozzle is an essential part of the hydraulic perforation tool.Insufficient penetration depth,caused by excessive jet distances,presents challenges during the perforation process.To overcome this,an optimization design of the nozzle structure is required to enhance the perforation efficiency.In this paper,a computational fluid-dynamic model for conical-cylindrical nozzles has been elaborated.To further improve the rock-breaking efficiency of the jet nozzle,a fillet design is introduced at the nozzle inlet section.The SST k-ωmodel is employed to account for turbulent flow effects in submerged conditions.The results indicate that the nozzle’s geometric parameters greatly influence the flow characteristics.The orthogonal experimental method is employed to optimize the flow channel structure of the nozzle,taking the length of constant velocity core as the evaluation index.The following optimized geometric parameters for the conical-cylindrical nozzle have been determined accordingly:a cylindrical segment diameter of 3.2 mm,a contraction angle of 12°,a contraction segment length of 8 mm,a cylindrical segment length of 6.4 mm,and a fillet radius of 2 mm.展开更多
JD Ceramics has been specializing in the field of air interlacing jets,air texturizing jets,and water jets over 29 years.With several years of technical accumulation and continuous equipments upgrades,we have been con...JD Ceramics has been specializing in the field of air interlacing jets,air texturizing jets,and water jets over 29 years.With several years of technical accumulation and continuous equipments upgrades,we have been consistently delivering high-precision,highquality,cost-effective ceramic nozzle solutions to the market.展开更多
The electromagnetic swirling flow in nozzle(EMSFN)technique is designed to mitigate the adverse effects of unstable and uneven flow within the submerged entry nozzle in continuous casting.Utilizing electromagnetic for...The electromagnetic swirling flow in nozzle(EMSFN)technique is designed to mitigate the adverse effects of unstable and uneven flow within the submerged entry nozzle in continuous casting.Utilizing electromagnetic forces,EMSFN stabilizes the flow within the nozzle,leading to a more controlled flow in the mold.Numerical simulations were used to quantitatively analyze the magnetic and flow fields in a slab continuous casting system under EMSFN.Results indicate that EMSFN significantly stabilizes the outflow from the nozzle,with stability increasing with higher current intensity.At 10,000 Ampere-turns(At)of the coil,meniscus fluctuations were unstable.They stabilized at 13,000 At,with minimal changes observed beyond this point.The optimal current intensity for stable mold flow,at a casting speed of 1.56 m/min,is 13,000 At.These findings confirm the effectiveness of EMSFN in stabilizing the internal flow field of the slab mold and determining optimal operational current intensity.展开更多
Understanding the motion behaviors of non-metallic inclusions in the liquid metal is important for clean steel production.High-temperature confocal laser scanning microscopy is applied to investigate the effect of dif...Understanding the motion behaviors of non-metallic inclusions in the liquid metal is important for clean steel production.High-temperature confocal laser scanning microscopy is applied to investigate the effect of different Ti and Al contents on the agglomeration behavior of non-metallic inclusions in low carbon steels.Furthermore,the agglomeration mechanism of inclusions was investigated through quantitative analysis of in-situ observation experiments and a modified Kralchevsky-Paunov model.The obtained results indicate that Al_(2)O_(3)is the main type inclusion in the low-alloys steels with both Al and Ti addition.This type of inclusion is more likely to absorb surrounding small-size inclusion particles,leading to a further growth for the cluster formation and contributing to a serious engineering problem,nozzle clogging.Besides,TiO_(x)is the main type inclusion in the molten steel with only Ti addition,and this type of inclusion is less likely to agglomerate and the individual inclusion particles show a‘free’motion with the fluid of molten steel.The difference between these two types of inclusions is due to the difference in attractive force and action distance at the meniscus created by the inclusion/steel/Ar multiple interfaces and influenced by the physical parameters,e.g.,contact angle and interface energy between inclusion and steel,and surface tension of the melt.展开更多
Gas–liquid two-phase jets exhibit markedly enhanced impact performance due to the violent collapse of entrained bubbles,which generates transient microjets and shock waves.The geometry of the nozzle is a decisive fac...Gas–liquid two-phase jets exhibit markedly enhanced impact performance due to the violent collapse of entrained bubbles,which generates transient microjets and shock waves.The geometry of the nozzle is a decisive factor in controlling jet formation,flow modulation,and impact efficiency.In this work,the structural optimization of gas–liquid two-phase nozzles was investigated numerically using the Volume of Fluid(VOF).Simulation results show that the aero-shaped nozzle delivers a significantly stronger impact on the target surface than conventional geometries.Specifically,its impact pressure is 21%higher than that of a conical straight nozzle and 37%higher than that of a conical nozzle.The aero nozzle not only increases peak impact pressure but also sustains it over a longer duration,leading to an overall improvement in energy transfer efficiency.Parametric analyses further reveal the key geometric conditions governing performance.When the nozzle curvature is set to 0.01,the jet achieves a higher and more stable surface pressure profile,maintaining elevated impact for a prolonged period.At an aspect ratio of 15,the jet exhibits pronounced pulsation under high pressure,thereby enhancing impact intensity.The contraction ratio exerts a non-monotonic influence:as it increases,impact pressure initially rises and subsequently declines,with an optimal value of 4 yielding the highest and most persistent impact pressure.Likewise,when the ratio of inlet length to outlet diameter is 2.5,the jet demonstrates the strongest impact on the target surface.展开更多
Combined cycle propulsion shows great potential for wide speed and altitude range flights.However,the jets of different types of engines may interact and form complex flow structures.Given that the specific effects of...Combined cycle propulsion shows great potential for wide speed and altitude range flights.However,the jets of different types of engines may interact and form complex flow structures.Given that the specific effects of jets interaction are closely related to combined nozzle configuration and working conditions,this paper analyzes the experiments of a simplified over-under combined nozzle and attempts to summarize the principles of the influence of twin-jet interaction on over-under combined nozzle performance.Firstly,twin-jet interaction directly changes the combined nozzle gross force via changing flow structure and parameters distribution inside the control volume.For example,the merging of supersonic jets forms wave systems,and the injection effect changes local pressure and the position of Free Shock Separation(FSS).Secondly,twin-jet interaction changes the force counting system.Assuming each flow-path as an isolated control volume leads to a mismatch of local pressure and reference ambient pressure.Thus,the combined nozzle should be considered as a whole control volume.Thirdly,twin-jet interaction may couple with jet-external interaction.On the one hand,jet-external interaction forms additional wave systems.On the other hand,the original expansion state of the nozzle during independent operation alters the performance baseline.Three practical experiments are conducted to verify these principles.These principles indicate that the influence of twin-jet interaction should be carefully considered in combined nozzle design.Utilizing the beneficial effect of twin-jet interaction can increase both the thrust and the lift,making the overall performance of the combined nozzle superior to the sum of two individual nozzles.However,twin-jet interaction may also decrease wall pressure,or alter the FSS position and flow direction of the over-expanded jet,resulting in a decrease in overall performance.These potential adverse effects should be avoided.展开更多
The turbulent characteristics of the top-blown Laval nozzle and the influence of pressure and Mach number were studied through numerical simulation.With 2.72%error between the results and the empirical formula,the res...The turbulent characteristics of the top-blown Laval nozzle and the influence of pressure and Mach number were studied through numerical simulation.With 2.72%error between the results and the empirical formula,the results are reliable.Nozzle fluid is influenced by pipe structure,causing pressure and density to drop as speed increases.Differences in pressure and velocity between the jet and surrounding gas lead to jet velocity attenuation,flow expansion,deflection,and eddy currents.The optimal top blowing pressure is 0.6 MPa,and the center velocity and width of the jet are 345 m/s and 0.124 m,respectively,at 20De(De is the nozzle exit diameter).It achieves a maximum jet velocity of 456 m/s.The optimal nozzle Mach number is 1.75,with a maximum jet velocity of 451 m/s.At 20D_(e),the jet center velocity is 338 m/s,with a width of 0.12 m.展开更多
The serpentine convergent-divergent nozzle represents an optimal configuration for nextgeneration fighter aircraft characterized by low detectability and high thrust-to-weight ratio.In contrast to the serpentine conve...The serpentine convergent-divergent nozzle represents an optimal configuration for nextgeneration fighter aircraft characterized by low detectability and high thrust-to-weight ratio.In contrast to the serpentine convergent nozzle,such configuration offers increased design flexibility with additional parameters,leading to heightened interactions among these parameters.As such,it is crucial to reveal the influence of design parameters on the aerodynamic performance of the serpentine convergent-divergent nozzle and the multifactor interaction,as well as its mechanism.Therefore,the influence,interaction and sensitivity of parameters on the aerodynamic performance of the nozzle were numerically investigated using the orthogonal test method.Additionally,the influence mechanism of the convergence angle,throat aspect ratio,and axial length to inlet diameter on the flow characteristics of the nozzle was investigated in detail.The results show that the convergence angle is identified as the main factor affecting the aerodynamic parameters of the nozzle.As the convergence angle increases,the thrust coefficient,total pressure recovery coefficient and discharge coefficient gradually decrease.The interaction between throat aspect ratio and other parameters is obvious.Different design parameters affect the local loss and the friction loss by affecting the curvature and wetted perimeter area,resulting in different aerodynamic characteristics of serpentine convergent-divergent nozzle.展开更多
Cold-flow experiments on planar Expansion Deflection(ED)nozzle flows are conducted under a simulated startup-shutdown process of rocket motors.The purpose is to investigate the flow and performance characteristics in ...Cold-flow experiments on planar Expansion Deflection(ED)nozzle flows are conducted under a simulated startup-shutdown process of rocket motors.The purpose is to investigate the flow and performance characteristics in ED nozzles,capture the behavior of shock flapping,and explore asymmetric flow dynamics utilizing a symmetric nozzle.A total pressure condition,characterized by rapid rise followed by a slow fall,is employed to simulate the continuous startup and shutdown processes.The schlieren imaging technique and high-frequency pressure transducers are employed to obtain the flow information.The experimental results indicate that the flow characteristics differ between the startup and shutdown processes with a hysteresis observed in the nozzle wake mode transition.During the startup process,the shock waves are pushed outward of the nozzle,while during the shutdown process,the flow propagates inward dominated by Mach stems.Counterintuitive results are demonstrated,namely,the mode transition is not the cause of the sudden thrust decrease,and the moment of maximum thrust does not coincide with the moment of maximum total pressure.During the operation of the nozzle,two stages of shock wave flapping occur,accompanied by significant wall pressure oscillations.These oscillation frequencies are demonstrated to be related to the inherent acoustic frequencies of the test chamber.An improved pressure ratio method is proposed to predict the position of the shock oscillation separation point.The prediction results revealed the shock behavior during the flapping process.展开更多
Enhancing the fermentation efficiency of waste in waste warehouses is pivotal for accelerating the pyrolysis process and minimizing harmful gas emissions.This study proposes an integrated approach,combining hot air in...Enhancing the fermentation efficiency of waste in waste warehouses is pivotal for accelerating the pyrolysis process and minimizing harmful gas emissions.This study proposes an integrated approach,combining hot air injection with dual atomizing nozzles,for the thermal treatment of waste piles.Numerical simulations are employed to investigate the influence of various parameters,namely,nozzle height,nozzle tilt angle,inlet air velocity and air temperature,on the droplet diffusion process,spread area,droplet temperature,and droplet size distribution.The results show that reducing the nozzle height increases the temperature of droplets upon their deposition on the waste pile.Specifically,when the nozzle height is lowered to 1.5 m,the temperature of the droplets reaching the waste pile is 1℃higher than when the nozzle height is set at 2 m.Furthermore,an increase in the nozzle tilt angle expands the overlapping heating area.For instance,when the nozzle angle is increased from 15°to 30°,the overlapping spread area expands by 3.21 m2.Additionally,increasing the inlet air velocity enhances the droplet diffusion range.At an air velocity of 2 m/s,the droplet diffusion range grows to 14.4 m,representing a 6.7%increase compared to the nowind condition.While the average droplet diameter decreases to 1.53 mm,the droplet temperature decreases by 1℃.Moreover,the droplet temperature is found to become smaller as the ambient temperature inside the waste warehouse declines.Specifically,a 5℃reduction in the ambient temperature results in a 1℃decrease in the average temperature of the atomized droplets.The study concludes that a nozzle height of 1.5 m and a nozzle tilt angle of 30°effectively meet practical heating requirements.展开更多
Taking a C1x motor with a backward-facing step which can generate a typical corner vortex as a reference,a numerical methodology using large eddy simulation was established in this study.Based on this methodology,the ...Taking a C1x motor with a backward-facing step which can generate a typical corner vortex as a reference,a numerical methodology using large eddy simulation was established in this study.Based on this methodology,the position of the backward-facing step of the motor was computed and analyzed to determine a basic configuration.Two key geometrical parameters,the head cavity angle and submerged nozzle cavity height,were subsequently introduced.Their effects on the corner vortex motion and their interactions with the acoustic pressure downstream of the backward-facing step were analyzed.The phenomena of vortex acoustic coupling and characteristics of pressure oscillations were further explored.The results show that the maximum error between the simulations and experimental data on the dominant frequency of pressure oscillations is 5.23%,which indicates that the numerical methodology built in this study is highly accurate.When the step is located at less than 5/8 of the total length of the combustion chamber,vortex acoustic coupling occurs,which can increase the pressure oscillations in the motor.Both the vorticity and the scale of vortices in the downstream step increase when the head cavity angle is greater than 24°,which increases the amplitude of the pressure oscillation by maximum 63.0%.The submerged nozzle cavity mainly affects the vortices in the cavity itself rather than those in the downstream step.When the height of the cavity increases from 10 to 20 mm,the pressure oscillation amplitude under the main frequency increases by 39.1%.As this height continues to increase,the amplitude of pressure oscillations increases but the primary frequency decreases.展开更多
Electrohydrodynamic(EHD)jet printing represents a novel micro/nano-scale additive manufacturing process that utilises a high-voltage induced electric field between the nozzle and the substrate to print micro/nanoscale...Electrohydrodynamic(EHD)jet printing represents a novel micro/nano-scale additive manufacturing process that utilises a high-voltage induced electric field between the nozzle and the substrate to print micro/nanoscale structures.EHD printing is particularly advantageous for the fabrication on flexible or non-flat substrates and of large aspect ratio micro/nanostructures and composite multi-material structures.Despite this,EHD printing has yet to be fully industrialised due to its low throughput,which is primarily caused by the limitations of serial additive printing technology.The parallel multi-nozzle array-based process has become the most promising option for EHD printing to achieve large-scale printing by increasing the number of nozzles to realise multichannel parallel printing.This paper reviews the recent development of multi-nozzle EHD printing technology,analyses jet motion with multi-nozzle,explains the origins of the electric field crosstalk effect under multi-nozzle and discusses several widely used methods for overcoming it.This work also summarises the impact of different process parameters on multi-nozzle EHD printing and describes the current manufacturing process using multi-nozzle as well as the method by which they can be realised independently.In addition,it presents an additional significant utilisation of multi-nozzle printing aside from enhancing single-nozzle production efficiency,which is the production of composite phase change materials through multi-nozzle.Finally,the future direction of multi-nozzle EHD printing development is discussed and envisioned.展开更多
基金supported by the National Outstanding Youth Science Fund Project of National Natural Science Foundation of China(52302031)National Natural Science Foundation of China(51932008 and 51772277)Central China Thousand Talents Project(204200510011).
文摘The reaction of carbon-free oxide-based(corundum,spinel,zirconia,and mullite)submerged entry nozzle(SEN)lining with rare earth inclusions and its anti-clogging effects under near working conditions were systematically studied.A variety of lining composite test methods were innovatively used to ensure the consistency of test conditions.The experimental results showed that the mullite(acidic oxide)has strong reactivity with rare earth inclusions,and the spinel(basic oxide)has stable chemical properties and weak reactivity with rare earth inclusions.Because alumina is one of the main reactants of clogging formation,corundum is not suitable for SEN lining.There are less clogs on the surface of zirconia,but it will be exsoluted and unstable.Therefore,solving the problem of zirconia exsolution will greatly strengthen its application in SEN lining.
基金partially supported by NSFC(11871133,12171498)partially supported by NSFC(11971402,12171401)the NSF of Fujian province,China(2020J01029)。
文摘In this paper,we study the transonic shock solutions to the steady Euler system in a quasi-one-dimensional divergent-convergent nozzle.For a given physical supersonic inflow at the entrance,we obtain exactly two non-isentropic transonic shock solutions for the exit pressure lying in a suitable range.In addition,we establish the monotonicity between the location of the transonic shock and the pressure downstream.
基金the financial support from the National Science and Technology Council,Taiwan(Grant No.MOST 111-2221-E-019-035-).
文摘The performance of a water jet propulsion system is related to the inlet duct,rotor,stator,and nozzle.Generally,the flow inlet design must fit the bottom line of the hull,and the design of the inlet duct is often limited by stern space.The entire section,from the rotor to the nozzle through the stator,must be designed based on system integration in that the individual performance of these three components will influence each other.Particularly,the section from the rotor to the nozzle significantly impacts the performance of a water jet propulsion system.This study focused on nozzle design and established referable analysis results to facilitate subsequent integrated studies on the design parameters regarding nozzle contour.Most existing studies concentrate on discussions on rotor design and the tip leakage flow of rotors or have replaced the existing complex computational domain with a simple flow field.However,research has yet to implement an integrated,optimal design of the section from the rotor to the nozzle.Given the above,our program conducted preliminary research on this system integration design issue,discussed the optimal nozzle for this section in-depth,and proposed design suggestions based on the findings.This program used an existing model as the design case.This study referred to the actual trial data as the design conditions for the proposed model.Unlike prior references’simple flow field form,this study added a jet ski geometry and free surface to the computational domain.After the linear hull shape was considered,the inflow in the inlet duct would be closer to the actual condition.Based on the numerical calculation result,this study recommends that the optimal nozzle outlet area should be 37%of the inlet area and that the nozzle contour should be linear.Furthermore,for the pump head,static pressure had a more significant impact than dynamic pressure.
基金support by the Center of Excellency Program of the Korea Science and Engineering Foundation (KOSEF)and Ministry of Science and Technology (MOST)(No.R11-2000-086-0000-0)through the Center for Advanced Plasma Surface Technology (CAPST)at the Sungkyunkwan University
文摘In this study, numerical analysis is performed to adopt the equivalence ratio on the high velocity oxygen fuel （HVOF） thermal spray coating systems equipped with a minimum length nozzle. The analysis is applied to investigate the axisymmetric, steady-state, turbulent, and chemically combusting flow both within the torch and in a free jet region between the torch and the substrate to be coated. The combustion is modeled using a single-step and eddy-dissipation model which assumes that the reaction rate is limited by the turbulent mixing rate of the fuel and oxidant. As the diameter of the nozzle throat is increased, the location of the Mach shock disc moves backward from the nozzle exit. As the throat diameter and the divergent portion are 6 mm and 8 mm, respectively, the pressure in the HVOF system is the lowest at the chamber and the expanding gas is steadily maintained with both high velocity and high temperature for different equivalence ratios. Thus, relatively minor amendments of the equivalence ratio and the geometry of HVOF can lead to improved control over coating characteristics.
基金Sponsored by the National Key R&D Project(Grant No.2019YFD1002500)the Key Projects of Science and Technology Support Plan of JiangsuP rovince(Grant No.BE2016341)the Open Fund of State Key Laboratory of Internal Combustion Engine(Grant No.GKF2015-004)。
文摘In order to analyze the spray characteristics of non-circular nozzle holes based on the air-assisted spray system, the spray characteristics of circular and non-circular nozzles were studied under the pressure of 0.2-0.6 MPa and the spray volume of 1000-5000 mL/h. Elliptical nozzle and triangular nozzle are classified as non-circular geometries. The spray cone angle was measured by processing the spray image captured by a CCD camera. The measured spray cone angles of the circular nozzles were analyzed, and the axis switching phenomenon of minor plane of elliptical nozzle was found during the test. Among the three shapes of nozzles, the elliptical nozzle had the largest spray cone angle, and the triangular nozzle had the smallest. The velocity field obtained depended on the PIV system. The results show that for axial velocity, elliptical orifice spray has greater kinetic energy and smaller droplet size under the same working parameters. Compared with the circular and elliptical nozzles, triangular orifice reached maximum spray velocity the fastest, but its velocity decay was the fastest. For radial velocity, away from the axis, the spray velocity of the elliptical orifice was less affected by the injection parameters, and the velocity was less than that of circular orifice and triangle orifice. Increasing air pressure will weaken radial propagation. The increase of liquid spraying rate had no remarkable effect on the increase of spraying rate. The results of particle size analysis show that the particle size of the non-circular orifice is reduced compared with that of the circular orifice, which promotes the breakup of droplets to a certain extent and enhances the atomization effect.
基金supported by the Fundamental Research Funds for the Central Universities(No.FRF-BD-23-01).
文摘Non-metallic inclusions in steel are a significant challenge,affecting material properties and leading to issues such as stress concentration,cracking,and accelerated corrosion.Current methods for removing inclusions,including bubble,electromagnetic stirring,filtration separation,fluid flow,and sedimentation,often struggle with the removal of fine inclusions.Apart from these known methods,pulsed electric current(PEC),as an emerging technology,has demonstrated immense potential and environmental advantages.PEC offers adjustable current parameters and simple equipment,making it an attractive alternative to traditional methods.Its green energy-saving features and excellent results in regulating inclusion morphology and migration,as well as inhibiting submerged entry nozzle(SEN)clogging,make it a promising technology.In comparison to continuous current technology,PEC has shown significant advantages in regulating inclusions,not only improving purification efficiency but also demonstrating outstanding performance in flow stability and energy consumption.The ability of PEC to efficiently reduce inclusion numbers enhances the purity and quality of molten steel,improving its mechanical properties.Currently,the theoretical basis for controlling the movement of inclusions by current is mainly composed of three major theories:the double electric layer theory,electromagnetic force reverse separation theory,and electric free energy drive theory.These theories together form an important framework for researchers to understand and optimize the behavior of impurity movement controlled by electric current.Looking ahead,PEC is expected to pave the way for new solutions in directional regulation of inclusion migration,efficient inclusion removal,SEN clogging prevention,and the purification of molten steel.
基金supported by the National Natural Science Foundation of China(52365056).
文摘Ultra-precision components have been widely used to produce advanced optoelectronic equipment.The so-called Electric field enhanced UltraViolet-Induced Jet Machining(EUV-INCJM)is an ultra-precision method that can achieve sub-nanometer level surface quality polishing.This study focuses on the application of the EUV-INCJM with different nozzle structures to a single-crystal of silicon.Two kinds of electro-optic-liquid coupling nozzles with single-jet and multi-jet focusing structures are proposed accordingly.Simulations and experiments have been conducted to verify the material removal performance of these nozzles.The simulation results show that,under the same condition,the flow velocity of the single-jet nozzle is 1.05 times higher than that achieved with the multi-jet configuration,while the current density of the latter is 1.63 times higher than that of the single-jet nozzle.For the single-crystal silicon,the material removal efficiency of the multi-jet focusing nozzle exceeds by about 1.4 times that of the single-jet.These results confirm that the material removal ability of the multi-jet configuration is more suitable for ultra-smooth surface polishing.The surface roughness of Si workpiece was reduced from Rq 1.55 to Rq 0.816 nm with valleys and peaks on its surface being almost completely removed.
文摘This paper mainly studies the well-posedness of steady incompressible impinging jet flow problem through a 3D axisymmetric finitely long nozzle.This problem originates from the physical phenomena encountered in practical engineering fields,such as in short take-off and vertical landing(STOVL)aircraft.Nowadays many intricate phenomena associated with impinging jet flows remain inadequately elucidated,which limits the ability to optimize aircraft design.Given a boundary condition in the inlet,the impinging jet problem is transformed into a Bernoulli-type free boundary problem according to the stream function.Then the variational method is used to study the corresponding variational problem with one parameter,thereby the wellposedness is established.The main conclusion is as follows.For a 3D axisymmetric finitely long nozzle and an infinitely long vertical wall,given an axial velocity in the inlet of nozzle,there exists a unique smooth incom‑pressible impinging jet flow such that the free boundary initiates smoothly at the endpoint of the nozzle and extends to infinity along the vertical wall at far fields.The key point is to investigate the regularity of the corner where the nozzle and the vertical axis intersect.
基金The authors gratefully acknowledge the financial support by the National Natural Science Foundation of China(No.52405272)the CNOOC’s major project during the 14th Five-Year Plan period“Key Technologies and Equipment for Measurement,Recording,and Testing-Development and Engineering of Integrated Perforation Technology Equipment Based on Reservoir Geology”and the National Science Foundation of Jiangsu Province(No.BK20220533).
文摘Hydraulic sandblasting perforation plays a crucial role in the fracturing and reconstruction of unconventional oil and gas reservoirs.The jet nozzle is an essential part of the hydraulic perforation tool.Insufficient penetration depth,caused by excessive jet distances,presents challenges during the perforation process.To overcome this,an optimization design of the nozzle structure is required to enhance the perforation efficiency.In this paper,a computational fluid-dynamic model for conical-cylindrical nozzles has been elaborated.To further improve the rock-breaking efficiency of the jet nozzle,a fillet design is introduced at the nozzle inlet section.The SST k-ωmodel is employed to account for turbulent flow effects in submerged conditions.The results indicate that the nozzle’s geometric parameters greatly influence the flow characteristics.The orthogonal experimental method is employed to optimize the flow channel structure of the nozzle,taking the length of constant velocity core as the evaluation index.The following optimized geometric parameters for the conical-cylindrical nozzle have been determined accordingly:a cylindrical segment diameter of 3.2 mm,a contraction angle of 12°,a contraction segment length of 8 mm,a cylindrical segment length of 6.4 mm,and a fillet radius of 2 mm.
文摘JD Ceramics has been specializing in the field of air interlacing jets,air texturizing jets,and water jets over 29 years.With several years of technical accumulation and continuous equipments upgrades,we have been consistently delivering high-precision,highquality,cost-effective ceramic nozzle solutions to the market.
基金supported by the Application Technology of Automotive Steels(No.2021040300048)the National Natural Science Foundation of China(No.52304347)+2 种基金Hebei Provincial Natural Science Foundation(No.E2019501008),China Baowu Low Carbon Metallurgy Innovation Foundation(BWLCF202320)Natural Science Foundation of Liaoning Province(Nos.2023-MSBA-135 and 2023-BSBA-107)Fundamental Research Funds for the Central Universities(Nos.N2409008 and N2409006).
文摘The electromagnetic swirling flow in nozzle(EMSFN)technique is designed to mitigate the adverse effects of unstable and uneven flow within the submerged entry nozzle in continuous casting.Utilizing electromagnetic forces,EMSFN stabilizes the flow within the nozzle,leading to a more controlled flow in the mold.Numerical simulations were used to quantitatively analyze the magnetic and flow fields in a slab continuous casting system under EMSFN.Results indicate that EMSFN significantly stabilizes the outflow from the nozzle,with stability increasing with higher current intensity.At 10,000 Ampere-turns(At)of the coil,meniscus fluctuations were unstable.They stabilized at 13,000 At,with minimal changes observed beyond this point.The optimal current intensity for stable mold flow,at a casting speed of 1.56 m/min,is 13,000 At.These findings confirm the effectiveness of EMSFN in stabilizing the internal flow field of the slab mold and determining optimal operational current intensity.
基金National Natural Science Foundation of China(Nos.U21A20116,U21A20117 and 52304347)National Natural Science Foundation of Liaoning(Nos.2023-MSBA-135 and 2023-BSBA-107)+1 种基金the Fundamental Research Funds for the Central Universities(Nos.N2409006 and N2409008)are acknowledged to support this workSwedish Foundation for International Cooperation in Research and Higher Education(STINT,Project No.IB2022-9228)is acknowledged by W.Mu to support his visit between KTH(Sweden)and NEU(China).
文摘Understanding the motion behaviors of non-metallic inclusions in the liquid metal is important for clean steel production.High-temperature confocal laser scanning microscopy is applied to investigate the effect of different Ti and Al contents on the agglomeration behavior of non-metallic inclusions in low carbon steels.Furthermore,the agglomeration mechanism of inclusions was investigated through quantitative analysis of in-situ observation experiments and a modified Kralchevsky-Paunov model.The obtained results indicate that Al_(2)O_(3)is the main type inclusion in the low-alloys steels with both Al and Ti addition.This type of inclusion is more likely to absorb surrounding small-size inclusion particles,leading to a further growth for the cluster formation and contributing to a serious engineering problem,nozzle clogging.Besides,TiO_(x)is the main type inclusion in the molten steel with only Ti addition,and this type of inclusion is less likely to agglomerate and the individual inclusion particles show a‘free’motion with the fluid of molten steel.The difference between these two types of inclusions is due to the difference in attractive force and action distance at the meniscus created by the inclusion/steel/Ar multiple interfaces and influenced by the physical parameters,e.g.,contact angle and interface energy between inclusion and steel,and surface tension of the melt.
基金funded by the National Natural Science Foundation of China,grant number 52204022Natural Science Foundation of Shandong Province,grant number ZR2022ME152+3 种基金Youth Innovation and Technology Support Program for Shandong Provincial Universities,grant number 2022KJ066National Key Research and Development Program of China,grant number 2021YFE0111400Shandong Provincial Key Research and Development Program(2025TSGCCZZB0419)The Major Special Project for Scientific and Technological Innovation of Dongying City(Science and Technology Development Guidance Plan),grant number 2023ZDJH110.
文摘Gas–liquid two-phase jets exhibit markedly enhanced impact performance due to the violent collapse of entrained bubbles,which generates transient microjets and shock waves.The geometry of the nozzle is a decisive factor in controlling jet formation,flow modulation,and impact efficiency.In this work,the structural optimization of gas–liquid two-phase nozzles was investigated numerically using the Volume of Fluid(VOF).Simulation results show that the aero-shaped nozzle delivers a significantly stronger impact on the target surface than conventional geometries.Specifically,its impact pressure is 21%higher than that of a conical straight nozzle and 37%higher than that of a conical nozzle.The aero nozzle not only increases peak impact pressure but also sustains it over a longer duration,leading to an overall improvement in energy transfer efficiency.Parametric analyses further reveal the key geometric conditions governing performance.When the nozzle curvature is set to 0.01,the jet achieves a higher and more stable surface pressure profile,maintaining elevated impact for a prolonged period.At an aspect ratio of 15,the jet exhibits pronounced pulsation under high pressure,thereby enhancing impact intensity.The contraction ratio exerts a non-monotonic influence:as it increases,impact pressure initially rises and subsequently declines,with an optimal value of 4 yielding the highest and most persistent impact pressure.Likewise,when the ratio of inlet length to outlet diameter is 2.5,the jet demonstrates the strongest impact on the target surface.
基金funded by the National Natural Science Foundation of China(No.12332018)the Science Center for Gas Turbine Project,China(No.P2022-B-I-006-001)the China Postdoctoral Science Foundation(No.2022M721598)。
文摘Combined cycle propulsion shows great potential for wide speed and altitude range flights.However,the jets of different types of engines may interact and form complex flow structures.Given that the specific effects of jets interaction are closely related to combined nozzle configuration and working conditions,this paper analyzes the experiments of a simplified over-under combined nozzle and attempts to summarize the principles of the influence of twin-jet interaction on over-under combined nozzle performance.Firstly,twin-jet interaction directly changes the combined nozzle gross force via changing flow structure and parameters distribution inside the control volume.For example,the merging of supersonic jets forms wave systems,and the injection effect changes local pressure and the position of Free Shock Separation(FSS).Secondly,twin-jet interaction changes the force counting system.Assuming each flow-path as an isolated control volume leads to a mismatch of local pressure and reference ambient pressure.Thus,the combined nozzle should be considered as a whole control volume.Thirdly,twin-jet interaction may couple with jet-external interaction.On the one hand,jet-external interaction forms additional wave systems.On the other hand,the original expansion state of the nozzle during independent operation alters the performance baseline.Three practical experiments are conducted to verify these principles.These principles indicate that the influence of twin-jet interaction should be carefully considered in combined nozzle design.Utilizing the beneficial effect of twin-jet interaction can increase both the thrust and the lift,making the overall performance of the combined nozzle superior to the sum of two individual nozzles.However,twin-jet interaction may also decrease wall pressure,or alter the FSS position and flow direction of the over-expanded jet,resulting in a decrease in overall performance.These potential adverse effects should be avoided.
基金supported by the National Key Research and Development Project of China(No.2022YFC3902001)the National Natural Science Foundation of China(No.52004340)the Guangxi Innovation-driven Development Project,China(Nos.Gui 2021AA12006 and 2021AB26024)。
文摘The turbulent characteristics of the top-blown Laval nozzle and the influence of pressure and Mach number were studied through numerical simulation.With 2.72%error between the results and the empirical formula,the results are reliable.Nozzle fluid is influenced by pipe structure,causing pressure and density to drop as speed increases.Differences in pressure and velocity between the jet and surrounding gas lead to jet velocity attenuation,flow expansion,deflection,and eddy currents.The optimal top blowing pressure is 0.6 MPa,and the center velocity and width of the jet are 345 m/s and 0.124 m,respectively,at 20De(De is the nozzle exit diameter).It achieves a maximum jet velocity of 456 m/s.The optimal nozzle Mach number is 1.75,with a maximum jet velocity of 451 m/s.At 20D_(e),the jet center velocity is 338 m/s,with a width of 0.12 m.
基金supported by the National Science and Technology Major Project of China(No.J2019-Ⅲ-0009-0053)。
文摘The serpentine convergent-divergent nozzle represents an optimal configuration for nextgeneration fighter aircraft characterized by low detectability and high thrust-to-weight ratio.In contrast to the serpentine convergent nozzle,such configuration offers increased design flexibility with additional parameters,leading to heightened interactions among these parameters.As such,it is crucial to reveal the influence of design parameters on the aerodynamic performance of the serpentine convergent-divergent nozzle and the multifactor interaction,as well as its mechanism.Therefore,the influence,interaction and sensitivity of parameters on the aerodynamic performance of the nozzle were numerically investigated using the orthogonal test method.Additionally,the influence mechanism of the convergence angle,throat aspect ratio,and axial length to inlet diameter on the flow characteristics of the nozzle was investigated in detail.The results show that the convergence angle is identified as the main factor affecting the aerodynamic parameters of the nozzle.As the convergence angle increases,the thrust coefficient,total pressure recovery coefficient and discharge coefficient gradually decrease.The interaction between throat aspect ratio and other parameters is obvious.Different design parameters affect the local loss and the friction loss by affecting the curvature and wetted perimeter area,resulting in different aerodynamic characteristics of serpentine convergent-divergent nozzle.
基金supported by the National Natural Science Foundation of China(No.12002102)。
文摘Cold-flow experiments on planar Expansion Deflection(ED)nozzle flows are conducted under a simulated startup-shutdown process of rocket motors.The purpose is to investigate the flow and performance characteristics in ED nozzles,capture the behavior of shock flapping,and explore asymmetric flow dynamics utilizing a symmetric nozzle.A total pressure condition,characterized by rapid rise followed by a slow fall,is employed to simulate the continuous startup and shutdown processes.The schlieren imaging technique and high-frequency pressure transducers are employed to obtain the flow information.The experimental results indicate that the flow characteristics differ between the startup and shutdown processes with a hysteresis observed in the nozzle wake mode transition.During the startup process,the shock waves are pushed outward of the nozzle,while during the shutdown process,the flow propagates inward dominated by Mach stems.Counterintuitive results are demonstrated,namely,the mode transition is not the cause of the sudden thrust decrease,and the moment of maximum thrust does not coincide with the moment of maximum total pressure.During the operation of the nozzle,two stages of shock wave flapping occur,accompanied by significant wall pressure oscillations.These oscillation frequencies are demonstrated to be related to the inherent acoustic frequencies of the test chamber.An improved pressure ratio method is proposed to predict the position of the shock oscillation separation point.The prediction results revealed the shock behavior during the flapping process.
文摘Enhancing the fermentation efficiency of waste in waste warehouses is pivotal for accelerating the pyrolysis process and minimizing harmful gas emissions.This study proposes an integrated approach,combining hot air injection with dual atomizing nozzles,for the thermal treatment of waste piles.Numerical simulations are employed to investigate the influence of various parameters,namely,nozzle height,nozzle tilt angle,inlet air velocity and air temperature,on the droplet diffusion process,spread area,droplet temperature,and droplet size distribution.The results show that reducing the nozzle height increases the temperature of droplets upon their deposition on the waste pile.Specifically,when the nozzle height is lowered to 1.5 m,the temperature of the droplets reaching the waste pile is 1℃higher than when the nozzle height is set at 2 m.Furthermore,an increase in the nozzle tilt angle expands the overlapping heating area.For instance,when the nozzle angle is increased from 15°to 30°,the overlapping spread area expands by 3.21 m2.Additionally,increasing the inlet air velocity enhances the droplet diffusion range.At an air velocity of 2 m/s,the droplet diffusion range grows to 14.4 m,representing a 6.7%increase compared to the nowind condition.While the average droplet diameter decreases to 1.53 mm,the droplet temperature decreases by 1℃.Moreover,the droplet temperature is found to become smaller as the ambient temperature inside the waste warehouse declines.Specifically,a 5℃reduction in the ambient temperature results in a 1℃decrease in the average temperature of the atomized droplets.The study concludes that a nozzle height of 1.5 m and a nozzle tilt angle of 30°effectively meet practical heating requirements.
基金Sponsored by the Natural Science Foundation of Shaanxi Province (Grant No. S2025-JC-YB-0532)the Practice and Innovation Funds for Graduate Students of Northwestern Polytechnical University (PF2024044)
文摘Taking a C1x motor with a backward-facing step which can generate a typical corner vortex as a reference,a numerical methodology using large eddy simulation was established in this study.Based on this methodology,the position of the backward-facing step of the motor was computed and analyzed to determine a basic configuration.Two key geometrical parameters,the head cavity angle and submerged nozzle cavity height,were subsequently introduced.Their effects on the corner vortex motion and their interactions with the acoustic pressure downstream of the backward-facing step were analyzed.The phenomena of vortex acoustic coupling and characteristics of pressure oscillations were further explored.The results show that the maximum error between the simulations and experimental data on the dominant frequency of pressure oscillations is 5.23%,which indicates that the numerical methodology built in this study is highly accurate.When the step is located at less than 5/8 of the total length of the combustion chamber,vortex acoustic coupling occurs,which can increase the pressure oscillations in the motor.Both the vorticity and the scale of vortices in the downstream step increase when the head cavity angle is greater than 24°,which increases the amplitude of the pressure oscillation by maximum 63.0%.The submerged nozzle cavity mainly affects the vortices in the cavity itself rather than those in the downstream step.When the height of the cavity increases from 10 to 20 mm,the pressure oscillation amplitude under the main frequency increases by 39.1%.As this height continues to increase,the amplitude of pressure oscillations increases but the primary frequency decreases.
基金National Natural Science Foundation of China(Grant Nos.52275345,52175331)the Support plan for Outstanding Youth Innovation Team in Universities of Shandong Province,China(2021KJ044)Natural Science Foundation of Shandong Province,China(Granted No.ZR2020ZD04)。
文摘Electrohydrodynamic(EHD)jet printing represents a novel micro/nano-scale additive manufacturing process that utilises a high-voltage induced electric field between the nozzle and the substrate to print micro/nanoscale structures.EHD printing is particularly advantageous for the fabrication on flexible or non-flat substrates and of large aspect ratio micro/nanostructures and composite multi-material structures.Despite this,EHD printing has yet to be fully industrialised due to its low throughput,which is primarily caused by the limitations of serial additive printing technology.The parallel multi-nozzle array-based process has become the most promising option for EHD printing to achieve large-scale printing by increasing the number of nozzles to realise multichannel parallel printing.This paper reviews the recent development of multi-nozzle EHD printing technology,analyses jet motion with multi-nozzle,explains the origins of the electric field crosstalk effect under multi-nozzle and discusses several widely used methods for overcoming it.This work also summarises the impact of different process parameters on multi-nozzle EHD printing and describes the current manufacturing process using multi-nozzle as well as the method by which they can be realised independently.In addition,it presents an additional significant utilisation of multi-nozzle printing aside from enhancing single-nozzle production efficiency,which is the production of composite phase change materials through multi-nozzle.Finally,the future direction of multi-nozzle EHD printing development is discussed and envisioned.
