涡轮冲压组合循环发动机引射过程数值模拟

Numerical simulation of ejector process within turbine-based combined-cycle engine

关键词:  涡轮冲压组合循环发动机+  涡轮发动机  冲压管道  引射工作过程

Key words:  TBCC engine~+  Turbine engine  Ramjet duct  Ejector process

摘要:

为了研究气流参数和几何参数对TBCC发动机引射工作过程的影响,基于CFD技术,采用数值求解N-S方程的方法,开展了对TBCC发动机引射工作过程的数值模拟研究。基于TBCC发动机引射过程数值模拟结果的分析,可以发现:随着引射段主流(涡轮发动机排出气流)的进口气流角度增加,总压和马赫数的分布趋于均匀,但是总压损失逐渐增大,因此在TBCC发动机引射段结构设计时,不应使涡轮发动机的排气角度过大。存在一个最小的引射段长度Lm in,当引射段长度小于Lm in时,随着引射段长度的增加,总压损失显著增大;当引射段长度大于Lm in时,随着引射段长度的增加,总压损失基本不发生变化。

Abstract:

Based on CFD technology,and Numerical Solution of Navier-Stokes equation,the effects of aerodynamic and geometrical parameters on the TBCC ejector process were analyzed.The Numerical Solution results show that entering angle of the major airflow and the ejector length have important influence on airflow mixing process in ejector.With the entering angle of major airflow increasing,the total pressure and Mach number tend to be distributed uniformly.But the total pressure loss increases gradually.Therefore,in the design process of TBCC engine,the exhaust angle of turbine engine is not immoderately big.At the same time,the computed results show that the total pressure loss increases with increasing length.However,once the length is above the minimum length,the total pressure loss is not obvious when the length increased.So,for practical integration of TBCC propulsion system components,matching aerodynamic and geometrical parameters is important.