迎风通量差分分裂法对边界层特性的数值模拟

迎风通量差分分裂法作为一种高效率的数值方法,已被广泛地用于模拟各种复杂流场,但用这类方法模拟有边界层存在的超音速粘性流场时,必须保证通量差分分裂为守恒的;否则,将在边界层内引入一个可观的虚假人工扩散项和压力梯度项,歪曲了边界层特性。本文就这个问题进行理论和数值的研究。

UPWIND FLUX DIFFERENCE SPLITTING METHOD FOR SIMULATING BOUNDARY LAYER CHARACTER

As a robust and efficient numerical method, the upwind flux differencesplitting method has been used to simulate complex viscous flow However, when the simulated supersonic viscous flow contains shear or boundary layers, the flux difference split must be conservative. If not, either an abnormally large numerical diffusion occurs within the boundary layer, or a fictitious pressure gradient is created that causes an unrealistic convection within the layer and misrepresents the boundary layer character. For this problem, theoretical analysis and numerical tests have been undertaken in this paper.