Simulation And Experimental Study On Colloidal Thruster

With the continuous development of aerospace technology,the application of microsatellites has become very extensive.Because the small size of tiny satellites,traditional chemical propulsion systems will no longer be suitable.As a new type of propulsion system,electric thruster,uses electric energy to generate thrust,which can satisfy the propulsion requirements of microsatellites.As one of the electric thrusters,the colloidal thruster uses dielectric liquid as working medium,though ionizing and accelerating the working fluid to generate thrust.Compared with other electric thrusters,colloidal thruster have the advantages of high precision and high specificity,and the research in foreign countries is relatively mature.China’s research on colloidal thruster started late,which is currently in the theoretical research stage.Colloidal thruster has not yet achieved specific applications in china,but this high-precision,high-impedance electric thruster will certainly play its advantage in future space missions.Through the investigation of a large number of literatures,this paper summarizes the research progress of colloidal thrusters at home and abroad,and summarizes the key technologies in the manufacturing process of colloidal thruster,such as emitter capillary and feed system manufacturing technology,neutralization technology,long-life research and micro-thrust measurement technology.Based on finite element analysis method,combined with electrohydrodynamics theory,COMSOL Multiphysics software is used to simulate the working process of colloidal thruster,and the stress of working medium in electric field is analyzed.The formation process of Taylor cone is explored.By changing the boundary conditions such as applied voltage and external pressure,the simulation results under different conditions are studied,the principle is analyzed,and each phenomenon is explained accordingly.According to the calculation of the simulation model,it can be found that the stable work of the colloidal thruster requires a suitable hydraulic pressure and working voltage.When the working voltage is too less,ions and small droplets cannot break away from the working medium and Taylor cone cannot be formed because the generated electric field force is less than the surface tension of the working medium.When the working voltage of the colloid thruster is greater than the stable working value,the whole injection system presents an unstable phenomenon,mainly because the emitter surface will appear the trend of multiple Taylor cones.When the liquid supply pressure of the colloid thruster is greater than the stable working value,the Taylor cone tip decomposition mechanism will be destroyed because the input is lager than the output,and the working fluid will flow out to connect the emitter and the extraction pole to cause a short circuit,so that the thruster cannot work normally.When the supply pressure of the colloidal thruster is too less,the working efficiency of the thruster will be affected due to insufficient liquid supply.After the simulation model is established,the accuracy of the simulation model is verified using theoretical formula calculations and specific experiments.Through the establishment of the colloidal thruster model,it can provide guidance for the actual design and manufacturing process in the future,and provide some help for the subsequent development of the colloidal thruster in China.