冲压空气涡轮泵供应系统方案设计及特性分析

Design and performance analysis on fuel feeding system for ram air turbo-pump

为了把冲压空气为动力的涡轮泵供应系统从亚燃冲压发动机拓展应用至超燃冲压发动机,基于煤油燃料的双燃烧室冲压发动机(DCR)提出了一种冲压空气涡轮泵供应系统方案。供应系统的设计方案中,对涡轮泵选型、系统的调控策略及取气/排气方案进行了初步设计。同时,建立了供应系统的静态模型,通过系统压力、流量及功率平衡组成非线性方程组,使用牛顿迭代法对非线性方程组进行数值求解,得到了冲压空气涡轮泵供应系统在不同工况下的静态特性。最后,分析了飞行Ma范围在3.5~5.5下涡轮泵的性能和调节的变化规律。结果表明,涡轮所需的空气流量约占DCR发动机捕获空气总流量的3%,取气方案对发动机气动性能影响不大;离心泵的特性参数相对稳定,可以一直处于高效率工况下工作,但系统对增压后的燃料利用不足,造成涡轮功率利用率较低。

In order to expand the application of turbo-pump fuel feeding system from ramjet to scramjet, which uses ram air as energy source, a scheme of turbo-pump fuel feed system based on kerosene-fueled dual-combustor ramjet(DCR) was proposed in this paper. The selection of turbo-pump, control strategy of the system and intaking and exhausting schemes of the ram air were primarily designed. Based on the balance relationship of pressure, mass flow rate and power of the system, the static models of the system were established, and the Newton iterative method was used to solve the model. With this method, the static characteristics of the system at difference working conditions were obtained. The performance and regulation change law of the turbo-pump at the fightMach number range from 3.5 to 5.5 were analyzed. The results show that the air flow needed by turbine is 3% of the general ram air quantity captured by DCR engine, so the air intaking and exhausting schemes have little influence on the aerodynamic performance of the engine; the feature parameters of the centrifugal pump are relatively stable, so the pump can work with high efficiency for a long time, but the pressured fuel is underutilized, causing low utilization ratio of the turbine power.