发表机构
Technical University of Munich（慕尼黑工业大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
提出一种在RANS框架内耦合一维底层求解器的多尺度近壁方法，无需细化粒子即可改善WCSPH壁面湍流预测，在高达8×10^7雷诺数下与参考解吻合，且计算开销低。
AI 中文摘要
在使用弱可压缩光滑粒子流体动力学（WCSPH）进行壁面约束湍流模拟时，实现足够的近壁分辨率仍然具有挑战性，因为局部粒子细化会带来严格的时间步长限制。本研究在雷诺平均纳维-斯托克斯（RANS）框架内提出了一种多尺度近壁方法，在不细化SPH粒子分布的情况下改善近壁预测。基于简化稳态$k$--$\omega$方程的局部一维底层求解器与每个近壁流体粒子耦合。开发了局部流量约束和基于摩擦速度的迭代方案来封闭并求解底层系统，同时通过具有局部反馈的双向剪切应力耦合来提高两个尺度之间的一致性。该方法在广泛的雷诺数范围内的湍流直通道流动以及涉及分离和再循环的波浪通道流动中进行了评估。结果表明，近壁速度、湍动能和摩擦系数的预测得到改善，收敛性令人满意，并与参考解吻合良好。特别是，该方法改善了传统壁面处理难以提供一致结果的近壁预测的收敛性，并在高达$8.0 \times 10^{7}$的雷诺数下与参考解紧密吻合，而无需近壁粒子细化。对于分离流动，使用近似均匀的粒子分布获得了与局部细化有限体积模拟相当的收敛性。这些改进以有限的计算开销实现，支持基于粒子的方法在涉及壁面约束湍流的工程流动中的应用。
英文摘要
Achieving sufficient near-wall resolution remains challenging for wall-bounded turbulence simulations using weakly compressible smoothed particle hydrodynamics (WCSPH), as local particle refinement imposes restrictive time-step requirements. This work proposes a multi-scale near-wall approach within the Reynolds-averaged Navier--Stokes (RANS) framework to improve near-wall predictions without refining the SPH particle distribution. A local one-dimensional sublayer solver based on the simplified steady $k$--$ω$ equations is coupled with each wall-adjacent fluid particle. A local flow-rate constraint and a friction-velocity-based iteration scheme are developed to close and solve the sublayer system, while a two-way shear-stress coupling with local feedback improves consistency between the two scales. The proposed approach is evaluated using turbulent straight-channel flows over a wide range of Reynolds numbers and a wavy-channel flow involving separation and recirculation. The results demonstrate improved near-wall velocity, turbulent kinetic energy and friction-coefficient predictions, satisfactory convergence, and good agreement with reference solutions. In particular, the approach improves the convergence of near-wall predictions where conventional wall treatments struggle to provide consistent results, and agrees closely with reference solutions at Reynolds numbers as high as $8.0 \times 10^{7}$ without near-wall particle refinement. For separated flow, convergence comparable to that of locally refined finite-volume simulations is obtained using an approximately uniform particle distribution. These improvements are achieved with limited computational overhead, supporting the application of particle-based methods to engineering flows involving wall-bounded turbulence.
Comments84 page 37 figures and 6 tables
