Design And High-Altitude Characteristics Study Of A Certain Type Aviation Piston Engine Radiator

Due to the thin air and insufficient cooling source,aviation piston engines will face huge heat dissipation problems when working at an altitude of 20 km.High altitude and long endurance have become the main direction of piston-powered aircraft development.Therefore,the design of radiator has become one of the key links to promote the development of aviation piston engines.In order to ensure the normal operation of the engine at an altitude of 20 km,the radiator of the aviation piston engine needs to be optimized to adapt to the high-altitude environment,but the design of the high-altitude radiator is very dependent on the test equipment and the high-altitude platform.The existing radiator research lacks high altitude The test data failed to form a complete theoretical system of high-altitude radiator design.This paper takes a certain type of aero piston engine as the research object,calculates the heat distribution of the engine,and designs a set of liquid-cooled radiators that can be used to dissipate heat at an altitude of 20 km.Finally,ground tests,simulation analyses,and simulations are performed on the radiator.The main work content and conclusions of optimization design and high-altitude characteristic analysis are as follows:First,combined with the characteristics of the 20 km altitude environment and engine parameters,the main components of the aero piston engine that require liquid cooling under working conditions are analyzed,and the heat distribution of the supercharged air system,lubricating oil system and engine cylinder head is calculated.Combining the demand of engine intake boost,and calculating according to the change of the boost gas state,in a 70 k W aviation piston engine,the compressed air heat produced by the boost air system is as high as 29 k W,which is equivalent to the heat dissipation of the engine cylinder head.It is one of the key heat loads that cause difficulty in high-altitude heat dissipation.Secondly,the overall arrangement scheme of two sets of aero piston engine liquid cooling system is designed,and the specific radiator arrangement form is determined based on the engine size and heat dissipation requirements.A one-dimensional simulation analysis was performed on each cooling circuit,and the design parameter details such as the size and form of each radiator were determined.Then,a three-dimensional simulation analysis of the high-altitude performance of the radiator was carried out based on the designed radiator models.The results showed that the calculation of the high-altitude conditions based on the ground test data would cause a calculation error of 10-15%.Finally,the designed radiator was verified by ground test and optimized design.The results of ground test verified the accuracy of the three-dimensional simulation analysis model of the radiator,and at the same time corrected the results of the one-dimensional simulation calculation.Through the verified three-dimensional simulation model,the performance of different optimization schemes and different altitudes of the radiator is calculated,and the specific scheme of radiator optimization and the altitude characteristic law of the radiator are obtained.