Design And Analysis Of Electrothermal MEMS Micro Thruster

Based on the background of the Tiantuo series micro-and nano-satellite,this paper has designed an electrothermal MEMS micro thrusters in detail,including micro valve,micro heater and micro nozzle.The main content includes the following several aspects.(1)Research of the significance of MEMS micro thruster,the application of MEMS technology in micro thruster and present situation is carried out.Then the target performance of micro thruster is obtained and tested with the help of simulation of working effect in orbit using STK software.Based on the target performance,the working type and process of micro thruster is developed.Finally the specific structure of micro thruster is designed.(2)A piezoelectric valve has been designed considering the general requirements of micro thruster,as well as the characteristics of different driving mode for micro valves.Kinetic theory of moving membrane and piezoelectric motor,which are important components of this piezoelectric valve,has been studied.By carrying out simulation with the help of ANSYS software,influence of moving membranes and piezoelectric motors with different parameters has been seek out.Internal flow field has been analysed in theory and simulated using ANSYS software.After that,output fluid velocity under different working state has been obtained.(3)Four micro heaters with different configurations has been designed according to the general requirements of micro thruster.Theoretical analysis of heat distribution in these four micro heaters has been carried out.After comparison of the temperature fields,which is obtained after simulation in ANSYS software,the best configuration for micro heater can be confirmed.(4)Flow characteristics in micro scale has been summarized and fluid flow inside the micro nozzle analysed in theory.Using ANSYS software,flow field in micro nozzles with different structural parameters such as inlet radius,exit radius,shrinkage ratio,expansion ratio,length of throat,width of throat,half angle of shrinkage,half angle of expansion,has been calculated.Influence rule of these parameters has been figured out after the calculation.