A multi-scale approach for wall-bounded WCSPH--RANS simulations
Abstract
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 × 107 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.
Related
- Extending convolutional neural networks to finite-volume meshes for fine-scale reconstruction of wall-bounded turbulence
- Synaptic Multi-Weight Wafer-Scale Domain Wall Magnetic Tunnel Junctions Driven by Spin Orbit Torque
- RBMD 2.0: Random batch molecular dynamics package for large-scale simulations on multi-GPU architectures
- Implementation and verification of a new free boundary module for Resistive Wall Modes simulations with the nonlinear 3D full MHD code SpeCyl
- Verification, Sensitivity, and Operating Limits of a GPU-Accelerated Planar WCSPH Model for Hydrodynamic Ram
BibTeX
@misc{wang2026multiscale,
title = {{A multi-scale approach for wall-bounded WCSPH--RANS simulations}},
author = {Feng Wang and Nikolaus Adams and Xiangyu Hu},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.21736},
eprint = {2609.21736},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.21736},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - A multi-scale approach for wall-bounded WCSPH--RANS simulations
AU - Feng Wang
AU - Nikolaus Adams
AU - Xiangyu Hu
PY - 2026
DA - 2026/09/18
PB - arXiv
DO - 10.48550/arxiv.2609.21736
UR - https://arxiv.org/abs/2609.21736
AB - 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 × 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.
ER -