The accuracy of Euler-Lagrange point-particle models employed in particle-laden fluid flow simulations depends on accurate estimation of the particle force through closure models. Typical force closure models require computation of the slip velocity at the particle location, which in turn requires accurate estimation of the undisturbed fluid velocity. Such an undisturbed velocity is not readily available when the fluid and particle phases are two-way coupled, due to the disturbance created by the particle's force in the nearby fluid velocity field. A common practice is to use the disturbed velocity to compute the particle force which can result in errors as much as 100% in predicting the particle dynamics. In this work, a correction scheme is developed that facilitates accurate estimation of the undisturbed fluid velocity in particle-laden fluid flows with and without no-slip walls. The model is generic and can handle particles of different size and density, arbitrary interpolation and projection functions, anisotropic grids with large aspect ratios, and wall-bounded flows. The present correction scheme is motivated by the recent work of Esmaily & Horwitz (JCP, 2018) on unbounded particle-laden flows. Modifications necessary for wall-bounded flows are developed such that the undisturbed fluid velocity at any wall distance is accurately recovered, asymptotically approaching the result of unbounded schemes for particles far away from walls. A detailed series of verification tests was conducted on settling velocity of a particle in parallel and perpendicular motions to a no-slip wall. A range of flow parameters and grid configurations; involving anisotropic rectilinear grids with aspect ratios typically encountered in particle-laden turbulent channel flows was considered in detail. When the wall effects are accounted for, the present correction scheme reduces the errors in predicting the near-wall particle motion by one order of magnitude smaller values compared to the unbounded correction schemes.

充满粒子的流体流动模拟中使用的Euler-Lagrange点粒子模型的准确性取决于通过闭合模型对粒子力的准确估计。典型的力闭合模型需要计算粒子位置的滑移速度，而这又需要准确估计未扰动的流体速度。当流体相和颗粒相双向耦合时，由于附近流体速度场中的颗粒力产生的干扰，这种不受干扰的速度不容易获得。一种常见的做法是使用受干扰的计算粒子力的速度，在预测粒子动力学时可能导致多达100％的误差。在这项工作中，开发了一种校正方案，该校正方案有助于准确估计带有和不带有防滑壁的含颗粒流体中未扰动的流体速度。该模型是通用模型，可以处理不同大小和密度的粒子，任意插值和投影函数，具有大长宽比的各向异性网格以及边界流。当前的校正方案是由Esmaily＆Horwitz（JCP，2018）最近对无边界含粒子流的研究所推动的。进行了有边界的流动所必需的修改，以使在任何壁距离处的不受干扰的流体速度都能准确地恢复，渐近地逼近远离壁的粒子的无穷方案的结果。对平行和垂直运动到防滑壁的颗粒的沉降速度进行了一系列详细的验证测试。一系列流量参数和网格配置；详细考虑了涉及各向异性的直线网格，这些网格具有在载有颗粒的湍流通道中通常遇到的长宽比。当考虑壁效应时，与无界校正方案相比，本校正方案将预测近壁粒子运动的误差减小了一个数量级。一系列流量参数和网格配置；详细考虑了涉及具有纵横比的各向异性直线网格，这些网格通常在载有颗粒的湍流通道中遇到。当考虑壁效应时，与无界校正方案相比，本校正方案将预测近壁粒子运动的误差减小了一个数量级。一系列流量参数和网格配置；详细考虑了涉及各向异性的直线网格，这些网格具有在载有颗粒的湍流通道中通常遇到的长宽比。当考虑壁效应时，与无边界校正方案相比，本校正方案将预测近壁粒子运动的误差减小了一个数量级。