The Modeling And Simulation Of UAV Integrated Thermal Management System

In recent years, unmanned aerial vehicle has been good development in both civil and military fields. Unmanned aerial vehicles are gradually replacing manned aerial vehicles combat mission in military fields. Military UAV has the characteristics of the limited size of body, wide flight envelope,as well as high requirement of stealth. These characteristics make various subsystems may not only face the problem of heat, but also face the problem of cold, If each subsystem operates independently will cause the energy of duplication and waste, Therefore, the research of UAV integrated thermal management system has the value of Engineering application.In this paper, design low load and high load conditions of three sets of environmental control system according to the cooling requirement of the UAV. Design liquid cooling and ventilation system for low load environmental control system. And design two systems of integration vapor cycle system,fuel system, cooling system and ventilation system for high load condition. Study on disturbance and control characteristics in full flight envelope under the system and provide a platform for the design and verification and Simulation Control Research on integrated thermal management system.Establish the mathematical model of thermal properties of moist air, fuel, refrigerant R134 a, JEP-8,ethylene glycol and water, and the mathematical model for various components of integrated thermal management system. Tank, the single-phase liquid / liquid heat exchanger, the single-phase air / liquid heat exchanger use lumped parameter method to establish transient model. Evaporator and condenser use moving boundary method to establish the dynamic model. Compressor, expansion valve, pump,valve use the lumped parameter method to establish stable model. After that, build the simulation model blocks and model library by using the MATLAB platform. And verify the accuracy of the model through the experimental data in literature or commercial FLOWMASTER software. Finally,establish simulation system models according to the design principle diagram of the UAV low load and high load environment control system and simulate and analysis of full flight envelope disturbance and control under thermal limit conditions. Make the system parameters meet the design requirements by use of PID control.