Study on Thermal Management for Cooling System of Aero-piston Engine

摘要

A model of thermal management for cooling system of aero-piston engine was presented in this study. The models of main parts in this system were also founded. Based on the measured value of temperature and pressure in the cylinder, the heat transfer coefficient between gas-fired and the cylinder wall was calculated by using the empirical formula. A heat transfer boundary condition between fins and cooling air was determined according to various Reynolds number of the air flow. Moreover, the method of finite element analysis was utilized to calculate the temperature of cylinder block. In the specified working condition of some two-stroke piston engine used in the unmanned aerial vehicle (UAV), the calculation and analysis were made to study on the effect of aircrew speed and flight height on the cylinder block temperature, as well as the effect of cylinder block temperature on airscrew speed by the thermal management model. The calculation results show that, as the flight height rises, the cylinder block temperature increases accordingly when engine power and airscrew speeds are kept constant; however, at the same height, the higher the airscrew speed is, the lower cylinder block temperature will be. The cylinder block temperature should be kept stable by regulating the airscrew speed.