Abstract In this work, we report on the development and initial validation of a new hybrid numerical model for the simulation of incompressible flow. A kinetic Lattice Boltzmann method (LBM) model using a reduced domain is nested within an inviscid flow field to provide increased simulation fidelity where desired, while leveraging the computational efficiency of inviscid solutions. We formulate a fully (or strongly) coupled approach, in which a Helmholtz decomposition is applied to the flow, separating the inviscid and viscous perturbation parts. The latter component is driven by the inviscid field through nonlinear inviscid-perturbation interaction terms that, in conventional Navier-Stokes solvers, would be expressed as volume forces. In the present work an equivalent LBM approach is presented where, as opposed to a body-force coupling, a strong coupling within the LBM collision operators is presented. The resulting hybrid LBM is applied to validation cases for a wave driven boundary layer and the flow past a cylinder.

中文翻译：

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一种基于 Lattice-Boltzmann 的微扰方法

摘要 在这项工作中，我们报告了用于模拟不可压缩流动的新混合数值模型的开发和初步验证。使用简化域的动力学格子玻尔兹曼方法 (LBM) 模型嵌套在无粘性流场中，以在需要时提供更高的模拟保真度，同时利用无粘性解决方案的计算效率。我们制定了一种完全（或强）耦合的方法，其中对流应用亥姆霍兹分解，分离无粘性和粘性扰动部分。后一个分量由无粘性场通过非线性无粘性-微扰相互作用项驱动，在传统的 Navier-Stokes 求解器中，将表示为体积力。在目前的工作中，提出了一种等效的 LBM 方法，与体力耦合相反，提出了 LBM 碰撞算子内的强耦合。由此产生的混合 LBM 应用于波浪驱动边界层和流经圆柱体的验证案例。