高原型无人机活塞发动机涡轮增压器匹配研究

Study on turbocharger matching application for piston engine of high plateau UAV

目的为了研究利用汽车发动机开发低成本民用航空无人机活塞发动机的应用价值,方法提出基于汽车涡轮增压发动机的高海拔性能劣化补偿目标的开发方法。选取某型车用活塞式涡轮增压发动机,分析变海拔环境下的增压器-发动机匹配条件,评估汽车涡轮增压发动机在无人机飞行包线的边界内性能变差程度。通过目标海拔高度条件下的仿真计算,获得新涡轮增压器的目标增压压比和发动机进气流量。以此计算结果为目标新增压器的性能边界,选定某型号涡轮增压器,其性能输出特性能够覆盖该发动机作为无人机动力的进气目标增压压力和流量。在平原和高高原条件下开展无人机飞行性能验证,对新开发增压器的压气叶轮和涡轮叶轮产生的压比、膨胀比以及各自的折合流量分别进行校核,分析无人机在不同海拔环境下的飞行测试数据。结果结果表明,新匹配的涡轮增压器在海拔4200 m的高高原条件下搭载试验发动机,压气机压比为3.2,换算流量0.092 kg/s,运行区间在增压器叶轮的MAP包络线以内,能够使无人机达到28.2%的悬停有效载荷比,性能达到高高原载重飞行的技术要求。结论利用汽车涡轮增压发动机,按照无人机飞行包线内工况,重新匹配涡轮增压器的压气机,并校核涡轮机运行工况,能够实现满足民用航空无人机对高高原低空载重飞行性能的基本要求,匹配方法为新产品开发应用提供了理论指导。

Objective In order to study the application value of using automobile engine to developing low cost civil aviation UAV piston engine,Methods a development method based on high altitude performance degradation compensation of automobile turbocharged engine was proposed.A certain type of automobile piston turbocharged engine for vehicle was selected to analyze the turbocharger-engine matching conditions under variable altitude environment,and evaluate the performance deterioration degree of automobile turbocharged engine within the boundary of UAV flight envelope.The target boost pressure ratio and engine intake flow of the new turbocharger were obtained through the simulation calculation under the condition of target altitude.With this calculation result as the performance boundary of the target new supercharger,a certain type of turbocharger was selected,and its performance output characteristics could cover the target boost pressure and flow rate of the engine as the UAV power.The UAV flight performance was verified under plain and high plateau conditions,and the pressure ratio,expansion ratio and reduced flow of the compressor and turbine impeller of the newly developed supercharger were checked respectively,and the flight test data of the UAV at different altitudes were analyzed.Results The results showed that the newly matched turbocharger was equipped with the test engine at a high altitude of 4200 meters,the compressor pressure ratio was 3.2,the converted flow rate was 0.092 kg/s,and the operation interval was within the MAP envelope of the turbocharger impeller,which could make the UAV reach the hovering payload ratio of 28.2%,and the performance could meet the technical requirements of high altitude load flight.Conclusion By using the automobile turbocharged engine,the compressor of the turbocharger was rematched according to the operating condition of the UAV flight envelope,and the turbine operating condition was checked,which could meet the basic requirements of the civil aviation UAV flight performance on high plateau and low altitude.The matching method provided theoretical guidance for the development and application of new products.