通过分析格式的耗散关系和重线性化技术,发展相应格式构造技术,提出了一类中心型的三阶非线性格式,格式具有与NND格式相当的网格模板.由于格式的线性形式具有很好的耗散特性,同时重线性化技术的使用使格式在光滑区尽量采用线性形式,从而理论上提升了计算对旋涡等结构的分辨和保持能力;另一方面,格式的非线性机制使格式在非光滑区退化为类NND格式,实现耗散和稳定机制.验证计算表明,格式能够开展粘性和旋涡及脉动流场的计算应用,算法形式简单,便于工程应用,容易进行有限体积推广.%Techniques are developed for the construction of difference schemes by analyzing their dissipation relations and using re-linearizing process; A center-typed third order nonlinear scheme is presented,which has the equivalent grid stencil as the NND scheme.Because the linear part of the scheme has well performance about the dissipative characteristics,and the linear form of it will be preferred as far as possible due to the re-linearizing technique,the improvement will be obtained theoretically on the resolution and maitainance ability about the vortices in computations; On the other hand,the scheme will change back into NND-like scheme by the nonlinear procedure when encoutnering non-smooth region,and the dissipation and stability mechanism will be brought into action.The validating computations show that,the scheme can be used in computations containing vortices and perturbations with viscosity,and the simple form of the algorithm makes it easily utilized in engineering purpose and extended to finite volume method.
展开▼
