This paper presents an integrated research scheme for vector deflection and energy extraction in a gas plasma jet under Magneto-Hydrodynamic(MHD)control.A MHDcontrolled thrust-vector test rig was used to conduct the e...This paper presents an integrated research scheme for vector deflection and energy extraction in a gas plasma jet under Magneto-Hydrodynamic(MHD)control.A MHDcontrolled thrust-vector test rig was used to conduct the experimental research.A gas plasma was obtained by injecting ionization seeds of Cs2CO3 into the combustion chamber via artificially forced ionization.The effects of the gas temperature and ionization seed mass fraction on the plasma jet deflection and energy extraction were experimentally verified under an applied magnetic field.The experimental results were analyzed theoretically.The results showed that the deflection amplitude of the gas plasma jet and the extracted voltage signal intensity increased with increasing gas temperature and the ionization seed mass fraction.The extracted dynamic voltage signals proved that the ionization seeds of Cs2CO3 induced gas ionization at 1173 K.The experiment verified that it is feasible to simultaneously achieve jet deflection and extract energy under the action of an external magnetic field.展开更多
Electrohydrodynamic(EHD)jet printing is a promising method for high-resolution manufacturing;however,it often suffers from jet deflection owing to the accumulation of residual charges within printed structures.These r...Electrohydrodynamic(EHD)jet printing is a promising method for high-resolution manufacturing;however,it often suffers from jet deflection owing to the accumulation of residual charges within printed structures.These residual charges lead to jet deflection.This study introduces a novel noncontact electric field-driven(NEFD)jet micro 3D printing technique to address these challenges.By decoupling the high-voltage power supply from both the printing material and substrate,NEFD jet micro 3D printing eliminates the pathway for charge injection into the printing material,reducing residual charges by a factor of five or more compared to EHD jet printing.Our research revealed an inherent attractive force between the material jet and previously deposited material,regardless of the material used.Furthermore,we demonstrate that employing a pre-defined allowance printing strategy during fabrication reduces the standard deviation of actual fiber spacing values from 11.4μm to 1.5μm,thereby improving the fiber spacing consistency.This enhanced control enabled the successful fabrication of line patterns with 20±1μm fiber diameters and 61.1±1.9μm fiber spacing,demonstrating the feasibility of NEFD jet micro 3D printing.This technique offers a novel solution for mitigating the challenges associated with electric fields and charge accumulation in EHD jet printing,paving the way for enhanced resolution and material compatibility in micro-/nanoscale additive manufacturing.展开更多
A new type jet, the oscillating & deflecting jet, is put forward and its oscillating and deflecting characteristics are investigated. The nozzle of the self-oscillating & deflecting water jet consists of an up...A new type jet, the oscillating & deflecting jet, is put forward and its oscillating and deflecting characteristics are investigated. The nozzle of the self-oscillating & deflecting water jet consists of an upstream nozzle, a downstream nozzle, an oscillating chamber and two switches. It is experimentally shown that the deflective angle may reach 9.53 degree. The generated pressure fluctuation is very regular and the jet can efficiently increase the ability for breaking and cutting by eliminating the water cushion effect associated with a continuous jet.展开更多
基金supported by the National Natural Science Foundation of China(No.90716025)。
文摘This paper presents an integrated research scheme for vector deflection and energy extraction in a gas plasma jet under Magneto-Hydrodynamic(MHD)control.A MHDcontrolled thrust-vector test rig was used to conduct the experimental research.A gas plasma was obtained by injecting ionization seeds of Cs2CO3 into the combustion chamber via artificially forced ionization.The effects of the gas temperature and ionization seed mass fraction on the plasma jet deflection and energy extraction were experimentally verified under an applied magnetic field.The experimental results were analyzed theoretically.The results showed that the deflection amplitude of the gas plasma jet and the extracted voltage signal intensity increased with increasing gas temperature and the ionization seed mass fraction.The extracted dynamic voltage signals proved that the ionization seeds of Cs2CO3 induced gas ionization at 1173 K.The experiment verified that it is feasible to simultaneously achieve jet deflection and extract energy under the action of an external magnetic field.
基金supported by National Natural Science Foundation of China(Grant Nos.52275345,52175331,51875300)Support Plan for Outstanding Youth Innovation Team in Universities of Shandong Province,China(Grant No.2021KJ044)Natural Science Foundation of Shandong Province,China(Grant No.ZR2020ZD04).
文摘Electrohydrodynamic(EHD)jet printing is a promising method for high-resolution manufacturing;however,it often suffers from jet deflection owing to the accumulation of residual charges within printed structures.These residual charges lead to jet deflection.This study introduces a novel noncontact electric field-driven(NEFD)jet micro 3D printing technique to address these challenges.By decoupling the high-voltage power supply from both the printing material and substrate,NEFD jet micro 3D printing eliminates the pathway for charge injection into the printing material,reducing residual charges by a factor of five or more compared to EHD jet printing.Our research revealed an inherent attractive force between the material jet and previously deposited material,regardless of the material used.Furthermore,we demonstrate that employing a pre-defined allowance printing strategy during fabrication reduces the standard deviation of actual fiber spacing values from 11.4μm to 1.5μm,thereby improving the fiber spacing consistency.This enhanced control enabled the successful fabrication of line patterns with 20±1μm fiber diameters and 61.1±1.9μm fiber spacing,demonstrating the feasibility of NEFD jet micro 3D printing.This technique offers a novel solution for mitigating the challenges associated with electric fields and charge accumulation in EHD jet printing,paving the way for enhanced resolution and material compatibility in micro-/nanoscale additive manufacturing.
基金Funded by National Natural Science Fund of China(No. 50074035)
文摘A new type jet, the oscillating & deflecting jet, is put forward and its oscillating and deflecting characteristics are investigated. The nozzle of the self-oscillating & deflecting water jet consists of an upstream nozzle, a downstream nozzle, an oscillating chamber and two switches. It is experimentally shown that the deflective angle may reach 9.53 degree. The generated pressure fluctuation is very regular and the jet can efficiently increase the ability for breaking and cutting by eliminating the water cushion effect associated with a continuous jet.
