超燃冲压发动机总体化性能分析

Analysis of Overall Scramjet Performance

关键词:  超燃冲压发动机  性能分析  三维抛物化N-S方程  一维NS方程 

Key words:  Scramjet  Performance analysis  Three-dimensional Parabolized Navier-Stokes equations  One-dimensional Navier-Stokes equation

摘要:

针对由后掠侧压进气道、矩形燃烧室和后掠侧板尾喷管构成的超燃冲压发动机模型,为了快速准确得到超燃冲压发动机的整机性能,建立了一套分析发动机总体性能的耦合流场计算方法。其中进气道和尾喷管流场分别求解三维单一气体和多组分抛物化N-S方程,燃烧室流场求解一维N-S方程,各部件在交接面处传递几何和流动参数。运用总体性能计算方法,研究了发动机构型的气动特性,给出了飞行高度、马赫数和攻角改变对发动机性能的影响规律。结果表明:该总体性能计算方法可用于超燃冲压发动机总体性能的快速预估；飞行高度对推力、升力和俯仰力矩的影响均较大且程度相近,三者随飞行高度增加均减小；飞行马赫数对发动机推力、升力的影响相近,对俯仰力矩的影响最大,三者随飞行马赫数增加均增加；飞行攻角对升力的影响最大,俯仰力矩次之,对推力的影响最小,随飞行攻角增加,发动机升力近似线性增加,推力和俯仰力矩分别呈增加和减小趋势。 

Abstract:

Scramjet model contains three components as bellow:aft swept sidewall compression inlet, rectangular combustor and aft swept sidewall nozzle. To get accurate scramjet performance results rapidly, a coupled method was set up to calculate scramjet flow field and study its performance. Inlet and nozzle were computed solving single and multiple species three-dimensional Parabolized Navier-Stokes equations, respectively. Combustor was computed solving one-dimensional Navier-Stokes equation. Geometric and flow parameters were transferred between adjacent components at their interface. Scramjet performance was studied using this coupled method. Flight conditions including altitude, Mach number and angle of attack were changed, respectively to study their influence on scramjet performance. Results show that this coupled method can give a rapid estimation of scramjet performance. Flight altitude has similar great impact on thrust, lift and pitching moment. All three performance parameters decrease as flight altitude increases. Flight Mach number has similar impact on thrust and lift, and the greatest impact on pitching moment. All three performance parameters increase as flight Mach number increases. Flight angle of attack impacts lift most, followed by pitching moment and thrust in order. As flight angle of attack increases, lift increases linearly, while thrust and pitching moment show a trend of increase and decrease, respectively. 