Simulation Of WorKing Performance Of Dual-modePropulsion System

With more and more diverse requirements of space missions, the traditional propulsion system demands more features function. Dual-mode propulsion system has been widely used, because of the advantages and multiple ignition orbit ascribed ratio. Dual-mode propulsion system can switch between different modes of according to the operation conditions.Thus it achieve diversification thruster work. Dual-mode propulsion system is Bipropellant propulsion mode and monopropellant propulsion modes. It use Bipropellant thruster On the conditions of Bipropellant Progression. When it is in the monopropellant propulsion mode, the system has two kinds of attitude control and position protection conditions. It uses chemical monopropellant thruster when it is in attitude control condition. It uses hydrazine arcjet thruster when it is in position control condition. Dual-mode propulsion system combines the dual benefits of high reliability, low thrust, the good pulse and high specific impulse. The system has better overall performance than the Bipropellant and monopropellant propulsion.This paper study the flow characteristics and thrust performance of the dual-mode propulsion system by the combination of three-dimensional simulation and one-dimensional simulation.Firstly, based on simulation modular thought, according to the different operating characteristics of the dual mode propulsion system,it is divided into the following modules:the valve parts, the thrust parts, other system components (cylinders, gas pipeline, tank pressurization system, liquid pipes). By analysisig the characteristics of their work feature, Iestablish the module mathematical models.Meanwhile I do three-dimensional simulation on the Bipropellant thruster,monopropellant hydrazine chemical thrusters and arcjet thruster. I gain the thrust temperature, and the pressure.By compared with the test results on the same conditions,it proves the simulation model is precise.Secondly, I do simulation on the valve parts(the check valve, the flow of self-locking Solenoid valves) by the three-dimensional simulation software.I analysis the transient and steady-state a flow characteristics through the different inlet pressure, the spool diameter and flow channel diameter.It provides a reference about the valves design and optimization of flow field.Finally,I do simulation research about the flow characteristics of Bipropellant propulsion and monopropellant propulsion mode. I analysis the transient and steady-state a flow characteristics of the system.At the same time, I gain the outlet mass flow on the different modes.I gain the thruster performance on the condition of Bipropellant mode through the builded and verified models.seting the systems outlet mass flow as the boundaryconditions of the thruster.Then I gain the hydrazine chemical thrusters and arcjet thruster performance on the condition of monopropellant mode through the builded and verified models,seting the systems outlet mass flow as the boundaryconditions of the thruster.