A Meshless WCSPH Boundary Treatment for Open-Channel Flow over Small-Scale Rough Bed

Abstract EN

A weakly compressible smoothed particle hydrodynamics (WCSPH) method was developed to model open-channel flow over rough bed.

An improved boundary treatment is proposed to quantitatively characterize bed roughness based on the ghost boundary particles (GBPs).

In this model, the velocities of GBPs are explicitly calculated by using evolutionary polynomial regression with a multiobjective genetic algorithm.

The simulation results show that the proposed boundary treatment can well reflect the influence of wall roughness on the vertical flow structure.

A fully developed open channel is established, and its flume length, processing time, and turbulent model are discussed.

The mixed-length-based subparticle scale (SPS) turbulence model is adopted to simulate uniform flow in open channel, and this model is compared with the Smagorinsky-based one.

For the modified WCSPH model, the results show that the calculated vertical velocity and turbulent shear stress distribution are in good agreement with experimental data and fit better than the calculations obtained from the traditional Smagorinsky-based model.