Optimization Design Of The Air-breathing Solar Thermal Propulsion System

The air-breathing solar thermal propulsion system is a development based on the previous solar thermal propulsion system.This system not only has the advantage in high specific impulse,but also some new superiorities such as carrying less working gas,operating longer,bringing more effective load.Because of these characteristics,the air-breathing solar thermal propulsion system will be extensively applied in low orbit satellite in weather survey,intelligence surveillance and reconnaissance.In the optimization research,the air-breathing solar thermal propulsion system was divided into four main components: air inlet,concentrator heat-exchange platelet and nozzle.The structure of the air inlet would be selected firstly.Then several key structure parameters were set up as variables and flow parameters as targets,finally the optimal flow parameters were obtained and the flow parameters changing regularity was founded according to the structure parameters.After optimization research,the flow mass collected from the air inlet improved 18% contrary to the previous research results.The optimization of the concentrator is including the primary concentrator and the refractive secondary concentrator.In the primary concentrator optimization the author gave the mathematical model and some constraint conditions and worked out the ideal result.While in the refractive secondary concentrator optimization,the author adopted regenerative cooling technology in order to improve the concentrator function.Compared to the prior research results,the mass of the primary concentrator decreased 32%,the absorbed energy increased 17% and the concentration ratio increased 20%.Moreover the refractive secondary concentrator got shield because of its thermal stress decreased 60%.The energy utilization improved 30%.The optimization of the heat-exchange platelet was relying on the integration function,including Simcode Design of Experiments and Optimization,of the Isight software.Then simulating and analyzing by fluid-solid coupled method after obtained the optimized parameters.The simulation showed that the working gas flow was more stable and the heat exchange efficient increased 8% than before.At last,the author designed a nozzle and calculated the propulsive force and the specific impulse of the system by theory analysis and numerical simulation method,and checked these parameters met the design requirement whether or not.Apart for that the author researched the supplement quantity of regenerative cooling material in detail,and gave the minimum supplement quantity which is only 70% of the preliminary selection.