大涵道比涡扇发动机中介机匣气动性能数值模拟研究

Numerical Simulation Research on Aerodynamic Performance of Intermediate Compressor Duct of High Bypass Ratio Turbofan Engine

以民用大涵道比涡扇发动机中介机匣为对象,采用数值模拟方法对其中的基本流场特征及流动机理进行细致分析,同时考虑发动机运行的实际工况,针对不同来流马赫数和进气节流比的情况,对中介机匣流动损失开展了对比研究。结果表明:大径向落差中介机匣主要的流动损失来自于端壁型线曲率及由此带来的压力梯度;支板的下壁面高损失区的影响范围明显大于上壁面损失区,下壁面型线曲率是影响中介机匣性能的关键因素;相同的来流马赫数情况下,中介机匣总压损失系数均随着进气节流比的降低呈递增趋势;相同进气节流比情况下,当来流马赫数低于0.3时,中介机匣损失水平相对较低;随着出口马赫数的增大,中介机匣总压损失随来流马赫数的增加呈现先降低后增加的趋势。

Taking the intermediate compressor duct of a civil high bypass ratio turbofan engine as an ob-ject,the basic flow field characteristics and flow mechanism of the intermediate compressor duct were an-alyzed in detail by means of numerical simulation.Furthermore,considering the actual operational condi-tions of the engine,a comparative study was carried out on the influence of different incoming Mach num-bers and intake throttle ratios on the flow loss of the intermediate compressor duct.The results show that the main flow loss of the intermediate compressor duct with large radial drop comes from the curvature of the endwall contour and the resulting pressure gradient.The impact region of high losses on the lower sur-face of the support plates is markedly larger than that on the upper surface,with the curvature of the low-er surface contour being a key factor affecting the performance of the intermediate compressor duct.Under the same incoming Mach number condition,the total pressure loss coefficient of the intermediate compres-sor duct exhibits an increasing trend with decreasing inlet throttle ratios.For identical intake throttle ratio,when the incoming Mach number is below O.3,the level of losses in the intermediate compressor duct remains relatively low.As the incoming Mach number increases,the total pressure loss in the intermediate compressor duct shows a tendency of initial decrease followed by an increase with rising incoming Mach numbers.