This study investigates the aerodynamic performance of the NACA 6412 airfoil with serrated trailing edges at various angles of attack(AOA)and Reynolds numbers.Two-dimensional and three-dimensional simulations were per...This study investigates the aerodynamic performance of the NACA 6412 airfoil with serrated trailing edges at various angles of attack(AOA)and Reynolds numbers.Two-dimensional and three-dimensional simulations were performed using Large Eddy Simulation(LES)and Reynolds-Averaged Navier-Stokes(RANS)models,and the results were compared with wind tunnel experiments at a Reynolds number of 4.52×10^(5).The primary objective was to assess the influence of trailing-edge serrations on lift and drag.The findings indicate that trailing-edge serrations,while generally associated with a slight increase in drag,contribute to improved lift characteristics and thereby enhance the overall aerodynamic efficiency,as reflected in a higher lift-to-drag ratio across varying angles of attack.展开更多
Recent development in space mission demands safer and more cost-effective space missions.Hybrid rocket engine technological advancements have prolonged a critical stage in their development and it is the better option...Recent development in space mission demands safer and more cost-effective space missions.Hybrid rocket engine technological advancements have prolonged a critical stage in their development and it is the better option for such space missions,as it has a lot of advantages over the solid rocket motor and liquid rocket engine.It is simple in design,has high thrust density,low weight,and is safer than a liquid rocket engine.It has restarted capability,safe,low explosion risk,and high specific impulse than a solid rocket motor.This paper shows the numerical analysis of a hybrid rocket engine.The paper highlights the initial boundary conditions in the analysis of a 300-N hybrid rocket engine.The process started with a chemical kinematic examination of engine-compatible fuels and oxidizers.This investigation provided the fundamental parameters required for the design and subsequent dimensioning of a hybrid rocket engine.It also produced a three-dimensional design model,performed numerical analysis using ANSYS software,and validated the findings using existing literature.Using the k-εturbulence model and transient solver on 8 mm port diameter for analyzing.The computational fluid dynamics model offered the qualities of a real hybrid rocket engine and it will be helpful to researchers and the scientific community in the future.展开更多
Hybrid-rocket propulsion,which combines the benefits of both liquid and solid propulsion,has gained attention for its safety,throttling capability,and cost-effectiveness.This study presents a combined experimental and...Hybrid-rocket propulsion,which combines the benefits of both liquid and solid propulsion,has gained attention for its safety,throttling capability,and cost-effectiveness.This study presents a combined experimental and theoretical investigation of a hybrid rocket engine using PVC/DBP as fuel and gaseous oxygen as the oxidizer.Four successive firings were conducted to analyze thrust,regression rate,chamber pressure,and specific impulse.NASA CEA was used to model the ideal combustion parameters.The PVC-DBP fuel formulation offers advantages such as ease of processing,availability,and controlled burning behavior.A series of experimental static tests were conducted using a hybrid-rocket engine equipped with a showerhead injector and a convergent-divergent nozzle.The findings demonstrate an inverse correlation between the mass flux of the oxidizer and the regression rate,with measurements dropping from 0.94 to 0.70 mm/s.over successive firings as port diameter increased from 15 to 28.15 mm.Thrust measurements followed a similar trend,declining from 220 to 50 N,reflecting reduced combustion intensity due to oxidizer dilution.Combustion efficiency improved from 52.16 to 59.55%,suggesting enhanced fuel regression dynamics across multiple firings.Additionally,comparative analysis reveals significant deviations from ideal behavior due to combustion inefficiencies and thermal losses,highlighting the need for nozzle and chamber optimization in practical hybrid engine systems.展开更多
With the advent of new technologies in space science,numerous missions and programs to launch satellites of various scales have received significant attention in the scientific community.However,there are a few comple...With the advent of new technologies in space science,numerous missions and programs to launch satellites of various scales have received significant attention in the scientific community.However,there are a few complexities involved to encourage activities such as space tourism and exploration due to the technical constraints that the launch vehicle poses.To surmount these challenges,a novel hybrid rocket engine must be designed which allows us to tailor the characteristics during its endurance simulations.In the current work,we have investigated the propellant’s thermal and flow characteristics such as glass transition and melting temperature,specific impulse,characteristic velocity,regression rate,and thrust,respectively,without compromising the performance of likewise liquid propellant engine.In the current work,we investigated propellant characteristics for pure paraffin wax with oxidizers,such as liquid oxygen and nitrous oxide,and pure paraffin with additives of aluminum,magnesium,and oxidizers.It was observed that pure paraffin with liquid oxygen and additive aluminum(30%weight)resulted in the highest specific impulse among other combinations,whereas differential scanning calorimeter investigations reported a reduction in latent heat with the increase in weight%of paraffin and aluminum powder.It is also suggested that heat flow at 10%weight complies with the hybrid rocket engine.展开更多
A hybrid rocket engine test bench experiment carried out the thrust 300 N,retaining nitrous gas as an oxidant,and 70 weight percent paraffin and 30 weight percent aluminum as fuel.To enhance the regression rate,new fu...A hybrid rocket engine test bench experiment carried out the thrust 300 N,retaining nitrous gas as an oxidant,and 70 weight percent paraffin and 30 weight percent aluminum as fuel.To enhance the regression rate,new fuels such as paraffin-based fuel have been created,allowing for more compact engine designs with high thrust densities.As a result,the use of hybrid rocket engines in several domains,such as sounding rockets and small satellites for educational purposes and launch vehicle propulsion systems,has become possible.The solid fuel grain diameter is assumed to spread the characterization under different conditions.Estimate the rocket performance in the assumed condition and develop the test bench setup.In this paper,the data are composed of a 165 mm length of grain,external diameter is 79.6 mm and internal/port diameter is 8 mm.The injector plate used in this experiment is three injector holes with 120°.This injector is a showerhead that is simple in design and it is frequently used in hybrid rocket engines.Constraints such as the pressure in the combustion chamber being 50 bar and the SS304 nozzle,thrust were measured.Four separate test series were conducted.In the first test,one hole in the showerhead injector geometry was studied.In the 2nd,3rd,and 4th tests,injector plates with three injector holes were used.The test bench of a hybrid rocket engine has many components(oxidizer/pressure tank,combustion chamber with the pre-combustion,post-combustion chamber,conical shape nozzle,igniter,injector plate,etc.).展开更多
文摘This study investigates the aerodynamic performance of the NACA 6412 airfoil with serrated trailing edges at various angles of attack(AOA)and Reynolds numbers.Two-dimensional and three-dimensional simulations were performed using Large Eddy Simulation(LES)and Reynolds-Averaged Navier-Stokes(RANS)models,and the results were compared with wind tunnel experiments at a Reynolds number of 4.52×10^(5).The primary objective was to assess the influence of trailing-edge serrations on lift and drag.The findings indicate that trailing-edge serrations,while generally associated with a slight increase in drag,contribute to improved lift characteristics and thereby enhance the overall aerodynamic efficiency,as reflected in a higher lift-to-drag ratio across varying angles of attack.
文摘Recent development in space mission demands safer and more cost-effective space missions.Hybrid rocket engine technological advancements have prolonged a critical stage in their development and it is the better option for such space missions,as it has a lot of advantages over the solid rocket motor and liquid rocket engine.It is simple in design,has high thrust density,low weight,and is safer than a liquid rocket engine.It has restarted capability,safe,low explosion risk,and high specific impulse than a solid rocket motor.This paper shows the numerical analysis of a hybrid rocket engine.The paper highlights the initial boundary conditions in the analysis of a 300-N hybrid rocket engine.The process started with a chemical kinematic examination of engine-compatible fuels and oxidizers.This investigation provided the fundamental parameters required for the design and subsequent dimensioning of a hybrid rocket engine.It also produced a three-dimensional design model,performed numerical analysis using ANSYS software,and validated the findings using existing literature.Using the k-εturbulence model and transient solver on 8 mm port diameter for analyzing.The computational fluid dynamics model offered the qualities of a real hybrid rocket engine and it will be helpful to researchers and the scientific community in the future.
文摘Hybrid-rocket propulsion,which combines the benefits of both liquid and solid propulsion,has gained attention for its safety,throttling capability,and cost-effectiveness.This study presents a combined experimental and theoretical investigation of a hybrid rocket engine using PVC/DBP as fuel and gaseous oxygen as the oxidizer.Four successive firings were conducted to analyze thrust,regression rate,chamber pressure,and specific impulse.NASA CEA was used to model the ideal combustion parameters.The PVC-DBP fuel formulation offers advantages such as ease of processing,availability,and controlled burning behavior.A series of experimental static tests were conducted using a hybrid-rocket engine equipped with a showerhead injector and a convergent-divergent nozzle.The findings demonstrate an inverse correlation between the mass flux of the oxidizer and the regression rate,with measurements dropping from 0.94 to 0.70 mm/s.over successive firings as port diameter increased from 15 to 28.15 mm.Thrust measurements followed a similar trend,declining from 220 to 50 N,reflecting reduced combustion intensity due to oxidizer dilution.Combustion efficiency improved from 52.16 to 59.55%,suggesting enhanced fuel regression dynamics across multiple firings.Additionally,comparative analysis reveals significant deviations from ideal behavior due to combustion inefficiencies and thermal losses,highlighting the need for nozzle and chamber optimization in practical hybrid engine systems.
文摘With the advent of new technologies in space science,numerous missions and programs to launch satellites of various scales have received significant attention in the scientific community.However,there are a few complexities involved to encourage activities such as space tourism and exploration due to the technical constraints that the launch vehicle poses.To surmount these challenges,a novel hybrid rocket engine must be designed which allows us to tailor the characteristics during its endurance simulations.In the current work,we have investigated the propellant’s thermal and flow characteristics such as glass transition and melting temperature,specific impulse,characteristic velocity,regression rate,and thrust,respectively,without compromising the performance of likewise liquid propellant engine.In the current work,we investigated propellant characteristics for pure paraffin wax with oxidizers,such as liquid oxygen and nitrous oxide,and pure paraffin with additives of aluminum,magnesium,and oxidizers.It was observed that pure paraffin with liquid oxygen and additive aluminum(30%weight)resulted in the highest specific impulse among other combinations,whereas differential scanning calorimeter investigations reported a reduction in latent heat with the increase in weight%of paraffin and aluminum powder.It is also suggested that heat flow at 10%weight complies with the hybrid rocket engine.
文摘A hybrid rocket engine test bench experiment carried out the thrust 300 N,retaining nitrous gas as an oxidant,and 70 weight percent paraffin and 30 weight percent aluminum as fuel.To enhance the regression rate,new fuels such as paraffin-based fuel have been created,allowing for more compact engine designs with high thrust densities.As a result,the use of hybrid rocket engines in several domains,such as sounding rockets and small satellites for educational purposes and launch vehicle propulsion systems,has become possible.The solid fuel grain diameter is assumed to spread the characterization under different conditions.Estimate the rocket performance in the assumed condition and develop the test bench setup.In this paper,the data are composed of a 165 mm length of grain,external diameter is 79.6 mm and internal/port diameter is 8 mm.The injector plate used in this experiment is three injector holes with 120°.This injector is a showerhead that is simple in design and it is frequently used in hybrid rocket engines.Constraints such as the pressure in the combustion chamber being 50 bar and the SS304 nozzle,thrust were measured.Four separate test series were conducted.In the first test,one hole in the showerhead injector geometry was studied.In the 2nd,3rd,and 4th tests,injector plates with three injector holes were used.The test bench of a hybrid rocket engine has many components(oxidizer/pressure tank,combustion chamber with the pre-combustion,post-combustion chamber,conical shape nozzle,igniter,injector plate,etc.).
