In this contribution we study the formal ability of a multi-resolution-times lattice Boltzmann scheme to approximate isothermal and thermal compressible Navier Stokes equations with a single particle distribution. More precisely, we consider a total of 12 classical square lattice Boltzmann schemes with prescribed sets of conserved and nonconserved moments. The question is to determine the algebraic expressions of the equilibrium functions for the nonconserved moments and the relaxation parameters associated to each scheme. We compare the fluid equations and the result of the Taylor expansion method at second order accuracy for bidimensional examples with a maximum of 17 velocities and three-dimensional schemes with at most 33 velocities. In some cases, it is not possible to fit exactly the physicalmodel. For several examples, we adjust the Navier Stokes equations and propose nontrivial expressions for the equilibria.
翻译:在本文中,我们研究了一种多分辨率时间格子波尔兹曼方案,可以使用单个粒子分布逼近等温和非等温可压缩纳维-斯托克斯方程。更具体地说,我们考虑了一共12种经典的正方形格子波尔兹曼方案,每种方案都有预定的守恒和非守恒矩集合。问题在于确定该方案的每个非守恒矩稳态函数的代数表达式以及弛豫参数。我们将流体方程和二维最大有17个速度的例子以及三维方案最多有33个速度的例子的二次精度泰勒展开方法进行比较。在某些情况下,不可能完全适配物理模型。对于几个例子,我们对纳维-斯托克斯方程进行了调整,并提出了稳态函数的非平凡表达式。