跨音速低展弦比轴流风扇转子内部流场的数值研究

NUMERICAL INVESTIGATION ON INTERNAL FLOW FIELD OF A TRANSONIC,LOW ASPECT RATIO AND AXIAL FLOW FAN ROTOR

关键词:  航空发动机  跨音速压气机  轴流风扇  纳维尔－斯托克斯方程  数值计算

Key words:  Aircraft engine  Transonic compressor  Axial flow fan  Navier Stokes equation  Numerical calculation

摘要:

采用三维雷诺平均Ｎ－Ｓ方程程序求解跨音速压气机风扇转子内部流场。这个程序采用有限体积显式时间推进方法求解控制方程，方程自变量选取在控制体顶点，采用简单的Ｈ型网格离散方程，离散后的代数方程用两步Ｒｕｎｇｅ－Ｋｕｔａ法进行时间推进求解，使用多重网格和当地时间步长方法加速计算收敛。程序中使用了Ｂａｌｄｗｉｎ－Ｌｏｍａｘ模型模拟湍流影响。用该方法计算了ＮＡＳＡ６７＃跨音速风扇转子的性能曲线，并重点计算最高效率点工况下内部流场。计算结果与实验结果的比较，证明该法可以用来模拟跨音速风扇转子内部流动。

Abstract:

A code to solve three dimensional Navier Stokes equation has been developed,which has been used to predict the flow field of a transonic,low aspect ratio and axial flow fan rotor.The code was based on an explicit,time marching and finite volume method.The independent variables of equations were stored at the corners of contorl volume.Turbulence was modeled by Baldwin Lomax eddy viscosity model.Two step Runge Kutta method was implemented to solve the algebraic equations.Some accelerating convergence techniques such as multi grid and local time step method were employed.Performance maps at design rotationg speed were calculated by the code.The emphasis of the paper is on the calculation of flow field at choked point,near stall point and at peak efficiency point.Comparation of predicted data with experimental result illustrates that the code can simulate a transonic,low aspect ratio and axial flow fan rotor