S形进气道流路造型方法及其对性能影响的研究

Study on Flow Path Shaping and Performance of S-Shaped Inlet

根据S形进气道的几何边界条件,提出了一种基于多项式的中心线及面积分布率曲线的流路造型方法。选择不同的拐点位置,采用该方法构造了9条具有代表性的中心线及面积分布率方程。组合不同的中心线和面积分布率曲线建立了相应的S形进气道的几何造型,并采用三维N-S方程进行求解,得到了总压恢复系数和DC60等性能指标。分析计算结果表明,中心线对S形进气道总压恢复和出口动压起着主要影响,随着中心线方程拐点位置后移,S形进气道总压恢复系数和出口动压呈明显增加趋势;中心线和面积分布率组合共同影响着DC60指标,当中心线拐点过于靠近进气道进口而面积分布率曲线拐点靠近进气道出口时,进气道下游的涡将会发展到出口,从而大幅度影响DC60指标。

Based on the geometric boundary conditions, a flow path shaping method is put forward by using a polynomial equation for the central line and area distribution of S-shaped inlet. Then nine typical central line and area distribution equations are constructed in terms of different position of inflection point. Composing different central line and area distribution equation, geometric mod- els of inlet are built up and 3D Navier Stokes equations are employed to perform the numerical simulation. The results indicate that central line plays a very important role on the total pressure recovery and outlet dynamic pressure of in- take. With the central line inflection moving forward from the inlet to the outlet, total pressure recovery and outlet dynamic pressure increase gradually. The central line and area distribution has couple effects on the DC60 index of intake outlet. While the central line inflection closing to the inlet and the area distribution inflection closing to the outlet, a vortex will appear in the downstream and extend to the outlet, which has a critical effect on the DC60 index of intake outlet.