摘要
基于Boltzmann-Shakhov模型方程,建立其沿特征线离散的一般形式,离散过程中对于碰撞项的处理采用显式和隐式加权平均的方法,其中权系数依赖于当地努森数,可根据当地流动尺度不同进行自适应调节。通过权系数的引入,对文献现有离散统一气体动理学格式进行改进,发展出具有尺度自适应特性的离散统一气体动理学格式(Scale Adaptive Discrete Unified Gas Kinetic Scheme,SADUGKS)。将SADUGKS格式应用于若干典型可压缩流动,对格式的有效性和尺度自适应特性进行了检验,所得数值结果与文献已有结果吻合较好,表明SADUGKS格式是一种求解宽范围努森数变化、跨流域多尺度流动问题的有效算法。
A general discretization of Boltzmann-Shakhov model equation along the characteristic line is obtained,where the time integration of collision term is handled as a weighted average between the implicit and explicit part.Moreover,the value of weight factor depends on the local Knudsen number,which represents the local flow regime and scale.With the aid of this weight factor,a scale adaptive discrete unified gas kinetic scheme(SADUGKS)has been developed as an improvement of the existing discrete unified gas kinetic scheme(DUGKS).Some typical compressible flows in different flow regimes are numerically simulated to demonstrate the validity and the property of scale adaption of SADUGKS.It turns out that the present SADUGKS is a valid numerical method for multiscale flow problems.
作者
许丁
孙祥
刘欣
XU Ding;SUN Xiang;LIU Xin(State Key Laboratory for Strength and Vibration of Mechanical Structures,School of Aerospace Engineering,Xi’an Jiaotong University,Xi’an 710049,China;Shaanxi Key Laboratory of Environment and Control for Flight Vehicle,Xi’an 710049,China)
出处
《空气动力学学报》
CSCD
北大核心
2020年第2期232-243,共12页
Acta Aerodynamica Sinica
基金
国家973计划项目(2013CB305702)
中央高校基本科研业务费专项资金资助。
