Abstract In near-wall turbulence modeling it is necessary to resolve a thin boundary layer containing high gradients of the solution. An accurate enough resolution of such a layer can take most of the computational time. The situation becomes even worse for unsteady problems. To avoid time-consuming computations, in the present paper a new approach is developed, which is based on a non-overlapping domain decomposition. The boundary condition of Robin type at the interface boundary between domains is constructed by transferring the original boundary condition from the wall. For the first time, recently developed unsteady interface boundary conditions of Robin type are used for the unsteady Reynolds Averaged Navier-Stokes equations. The interface boundary conditions contain a memory term which takes into account the nonlocal effect in time to be taken into account for essential unsteady problems. In the case of stationary solutions the new approach automatically reduces to the technique earlier developed for the steady problems. The considered test cases demonstrate that the effect of the memory term can be significant for the accuracy of the near-wall domain decomposition. The criteria for importance of the memory term in the interface boundary condition are formulated and confirmed for turbulent flows.

中文翻译：

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用于模拟本质上不稳定的近壁湍流的非重叠域分解

摘要 在近壁湍流建模中，需要解析包含高梯度解的薄边界层。这种层的足够准确的分辨率可能会占用大部分计算时间。对于不稳定的问题，情况会变得更糟。为了避免耗时的计算，本文开发了一种基于非重叠域分解的新方法。域间界面边界的Robin型边界条件是通过从壁面转移原始边界条件来构建的。最近开发的 Robin 型非定常界面边界条件首次用于非定常雷诺平均纳维-斯托克斯方程。界面边界条件包含一个记忆项，它考虑了非定常效应，以便在必要的非定常问题中考虑。在固定解的情况下，新方法会自动简化为早期为稳定问题开发的技术。所考虑的测试案例表明，记忆项的影响对于近壁域分解的准确性可能很重要。为湍流制定并确认了界面边界条件中记忆项的重要性标准。所考虑的测试案例表明，记忆项的影响对于近壁域分解的准确性可能很重要。为湍流制定并确认了界面边界条件中记忆项的重要性标准。所考虑的测试案例表明，记忆项的影响对于近壁域分解的准确性可能很重要。为湍流制定并确认了界面边界条件中记忆项的重要性标准。