两方程k-g模式在全机大迎角流场中的应用研究

Numerical simulation for transonic flows at high incidence around a complete fighter with two-equation k-g model

采用由两方程k-ω模式推导得到的k-g模式数值模拟完整飞机构形的跨声速大迎角流场。由于k-g模式具有勿需使用到物面的法向距离、简单的源项和直接的边界条件等特点,可以方便地推广到包含复杂外形的多块网格系统。与雷诺平均N av ier-S tokes方程组的求解方法类似,k-g模式方程也采用显式R unge-K u tta方法进行时间推进,用中心加人工粘性格式进行空间离散。采用相同的方法数值模拟NA SA TN D-712翼身组合体标模迎角为12.5°和26.2°的流场来检验程序的可靠性,与可获得的实验数据进行对比分析并获得满意结果。与此同时,还使用了B a ldw in-Lom ax代数模式以作比较。

The transonic flows at high angle of attack around a twin-tail complete fighter configuration have been numerically simulated with a two-equation model k-g, which was derived from model k-ω. Model very st k-g, because of such advantages as no use of normal-to-wall distance, simple source terms and raightforward boundary conditions ,can be easily extended to practical and complex configurations. According to the geometric characteristics of the fighter, three-block structured grids with point-topoint boundaries are generated by combination of algebraic and solving elliptic equation methods. On the basis of multi-block mesh system, zonal method is employed to solve the equations of k-g model and the mean flow. Concretely, the equations of model k-g are explicitly integrated similarly as the Reynolds averaged Navier-Stokes equations with central-differencing and artificial dissipation for each sub-zone. The similar transonic flows at high angle of attack around the NASA TN D-712 standard wing-fuselage model are used to validate the codes. The computational results are compared to available experiment data and good agreement is achieved. At the same time, another wide used turbulence model, the algebraic Baldwin-Lomax model, is also applied for these viscous flows.