RBCC发动机火箭推力增益之探讨

为提高火箭基冲压组合循环(RBCC)发动机火箭冲压模态下火箭推力增益,基于模拟飞行Ma=4来流条件的数值计算结果,分析了火箭射流与冲压主流超/超剪切流动的特性,探讨了火箭推力增益的组成,并给出了提高火箭推力增益的措施:1)冲压流道、火箭工作参数的选取必须确保两股超声速剪切流之间的流动匹配,在有限空间内快速、低损的实现高能火箭射流与低能冲压主流间的动量及质量输运,最大限度地提高发动机喷管排气速度及压力;2)采用高室压火箭,通过增加推力室室压,提高火箭燃气膨胀程度,减小火箭推力增益损失。

Discussion of rocket thrust augmentation for RBCC engine

In order to enhance rocket thrust augmentation of rocket-based combined-cycle (RBCC) engines in rocket ramjet mode,the flow interaction characteristics between rocket ejection and ramjet inflow are analyzed,as well as constitution of thrust augmentation is discussed on the basis of the numerical simulation result in the Maeh 4 coming flow condition of the simulated flight.Some measures for improving rocket thrust augmentation are given as follows:1) the selection of ramjet passageway and rocket ejection parameters must guarantee the flow matching between two supersonic velocity shear flows to achieve the weight transportation and momentum between high energy rocket jet flow and low energy ramjet mainstream rapidly and efficiently in the finite space of ramjet combustor,and improve the exhaust velocity and pressure of engine nozzle in maximum limit;2) the rocket with high chamber pressure should be adopted to enhance expending degree of rocket exhausted gas and reduce the thrust augmentation loss of rocket.