Numerical Simulation of Water Flow over a Stair Through Improved Weakly Compressible Moving Particle Semi-implicit Method

This paper analyzes the dam-break flow propagation over a stair using a novel version of the weakly compressible moving particle semi-implicit method, which was improved with the particle shifting technique and the quintic kernel function. The proposed method was validated with the experimental data of dam-break propagation. The simulation was conducted in two scenarios, in the first of which an obstacle-shaped stair was located in the flow direction, and the collision of the water volume with the stair was modeled through the proposed approach. The results were then compared with those obtained from the finite-volume method (FVM) in STAR-CD. In the second scenario, the dam-break flow descended a stair, reaching the bed and propagating in two directions: toward the right wall and backward near the stair wall. The submerged hydraulic jump was created near the stair wall because the flow did not have enough length to make the conjugation depth. The simulation results from both scenarios were consistent with those of the FVM solver. Furthermore, a quantitative analysis was performed by calculating error norms, resulting in values within the 10(-4) range. The analysis indicated a high level of accuracy and consistency between the simulated results and the reference data. In addition, the issue of particle clustering was addressed effectively using the particle shifting approach.