Study On Behaviors And Rules Of Electrostatic Atomization Of Gel Propellant

Micro propulsion system is deeply researched as the fast development of small satellites,gel propellant is thought the important fuel in the future aerospace propulsion system,which owns the main advantage of solid fuel and liquid fuel,and possesses broad application prospects.The traditional atomization mode can't get the ideal droplet diameter and be controlled easily because of the shear-thinning and thixotropic characteristics,which limits the improvement of combustion efficiency.Electrostatic atomization technology could be used in atomization of viscous liquid,which utilizes electric field force to stretch the liquid to break into micro-nano level droplets.This thesis put forward to use electrostatic atomization technology to atomize the gel propellant,and studies on the atomization behaviors and rules,electrostatic atomization of multi-nozzle structure and so on,the main contents are listed as follows:(1)The feasibility of electrostatic atomization of gel propellant is simulated and analyzed,and electrostatic atomization results in different applied voltages,viscosity and surface tension is investigated to get the ideal parameters.(2)Water gel simulants is prepared to replace the true gel propellant in experiment,which owns the similar rheological characteristic with true gel propellant.Experiment platform is set up to measure the parameter of electrostatic atomization of gel propellant,it is found that the flow rate of solution is between 10?30 ?L/h and the operating voltage is between 5?8 kV.The influence of collector distance,nozzle modification and solution characteristic on the diameter distribution of atomization droplet and jet-spread angle in electrostatic atomization is explored,it is concluded that the diameter of atomization droplet and jet-spread angle decreases as the increase of collector distance and the decrease of inner diameter of nozzle.Based on this,it is analyzed that if the gel propellant could be used in multi-nozzle structure and owned well atomization results.(3)The nozzles is arranged as three layers and regular hexagon structure to explore the electric field restrain effect between the nozzles,the influence of distance between nozzles,nozzle modification and length of nozzle on the electric field restrain effect is simulated and analyzed,so the distance between nozzles is set as 10mm initially.Then the height gradient distribution of nozzles is explored to weaken electric field restrain effect,and the height gradient of the first and second layer nozzles are 3.5 mm and 1.5 mm respectively.Finally,the influence of the height of storage chamber and height gradient distribution of nozzles on the flow homogeneity of all nozzles is studied.Ultimately,the structure parameter of multi-nozzle structure could be got,which makes the electric field and flow rate uniform,and could be used in steady electrostatic atomization of gel propellant.(4)Based on the structure parameter,the multi-nozzle structure is designed and processed,then the gel propellant is used in multi-nozzle structure and the atomization effect is well;In order to make the multi-nozzle structure and electrostatic atomization technology be used in gel bipropellant system,the experiment of pressure impact and induced jets of stainless steel wire mesh is explored.Finally,gel bipropellant multi-nozzle system is designed to be used in two-component jet atomization combustion test.