SPH simulations of turbulent flow in curved pipes with different geometries. A comparison with experiments

TL;DR

This paper presents a weakly compressible SPH simulation approach coupled with LES turbulence modeling to accurately reproduce swirling secondary flows in various curved pipe geometries, validated against experimental data.

Contribution

It introduces a validated SPH-based numerical scheme with non-reflecting boundary conditions for simulating turbulent flows in curved pipes, demonstrating good agreement with experiments across multiple geometries.

Findings

SPH simulations match experimental velocity profiles within 1.8% deviation.

The model effectively captures flow behavior in different pipe geometries.

Results show SPH's potential for engineering applications involving curved flows.

Abstract

The swirling secondary flow in curved pipes is studied in three-space dimensions using a weakly compressible Smoothed Particle Hydrodynamics (WCSPH) formulation coupled to new non-reflecting outflow boundary conditions. A large-eddy simulation (LES) model for turbulence is benchmarked with existing experimental data. After validation of the present model against experimental results for a 90 grades pipe bend, a detailed numerical study aimed at reproducing experimental flow measurements for a wide range of Reynolds numbers has been performed for different pipe geometries, including U pipe bends, S-shaped pipes and helically coiled pipes. In all cases, the SPH calculated behavior shows reasonably good agreement with the measurements across and downstream the bend in terms of streamwise velocity profiles and cross-sectional contours. Maximum mean-root-square deviations from the experimentally obtained profiles are always less than 1.8%. This combined with the very good matching between the SPH and the experimental cross-sectional contours shows the uprising capabilities of the present scheme for handling engineering applications with streamline curvature, such as flows in bends and manifolds.