航空汽油机双级涡轮增压器系统的基本模型

ESSENTIAL MODEL FOR CYCLE DESIGN AND ALTITUDE PERFOR-MANCE ANALYSIS OF THE TWO-STAGE TURBOCHARGING SYSTEM OF GASOLINE AEROENGINES

为进行高空大气研究或者高空无人侦察,需要使用适合于1至3万米高空低速长航时飞行的加装多级涡轮增压器的活塞发动机系统。本文对于其中的双级涡轮增压器子系统的设计和飞行高度特性分析问题,给出了基本的气动热力学方程组和辅助模型方程组。方程组考虑到最简单的压气机-涡轮共同工作特性,考虑到增压器的总体与部件的气动设计可行条件的约束,发展的计算程序还考虑到必要的一维流动约束条件。这些确保了压气机、涡轮部件的设计存在可行解并可优化。于是得到了一种比总体部件法模拟方法清晰快速得多的基本设计与分析模型。算例已分析出一般双级增压的发动机系统的全功率高度特性的基本规律和物理特征,并随之提供出飞行控制中的增压器子系统和活塞发动机的调节计划数据。

In order to survey upper atmosphere phenomena or carry out high-altitude unmanned reconnaissance, a reciprocating gasoline engine system equipped with a sub-system of nmlti-stage turbochargers is the proper selection. This system can work to as high-altitude as 10 to 30 kilometers and last to as long flight time as several days when using a lower enough vehicle cruising speed. This paper deals with primarily the two-stage turbocharger sub-system＇s design and altitude-performance analysis issues for the full-power and higher altitude down-power running states of the engine system. With the assumption of engine-blackbox, a set of newly established essential aerothermodynamic equations and a group of additional models are proposed. The equations considered first, the most simplified compressor / turbine cooperation curves, second, the constraints from the aerodynamic design technology for both overall and component designs of the turbochargers. In the corresponding computer program, the necessary aerodynamic losses and the constraints for 1-D flow are also considered. Those involved considerations are important for obtaining the feasible and optimize-able turbocharger designs. This panel of approaches thus affords a kind of clear and time-saving essential design and analysis model, when compared with a full-map based numerical component simulation method. By this sub-system model, two examples of cycle designs with their off-design point altitude-performance analyses are available. With the examples, the essential rules and the physical characteristics along a practicable altitude span are revealed. Meanwhile it provides a group of curves of the flight adjusting plans for both engine and turbocharging system needed by the Electronic Control Units （ECU）.