spheric_testcase6_movingsquare
The flow across a square cylinder is an important test case for the validation of separated flows especially in the turbulent regime. In the past, it has been regularly used to validate Large Eddy Simulation (LES) models. The test proposed is a tough benchmark for Lagrangian solvers like SPH. The main goal is to prove that the particle solver adopted is able to generate diffuse and convect correctly the unsteady vorticity. Due to the presence of sharp edges the vorticity generated is quite intense. Even though the geometry is very simple, the flow can be very complex since increasing the Reynolds Number the vorticity decays at lower scales.
- L = 2π m
- U = 1 m/s
- Re = 100
- ρ0 = 1 kg/m3
- μ = 10-2 Pa·s
- cs = 50 m/s
- n = 705600
- Δr = 1.25x10-2 m
- h / Δr = 4
- α = 0.0
- δ = 1.0
- Δt = 1.67x10-5 s
- BCs: Boundary Integrals, Free-Slip
- No turbulence model
In the following figure the snapshots of both simulations, the reference one computed with Finite Difference Method and the one computed with AQUAgpusph, are shown:
Even though small discrepancies can be appreciated in the flow detached from front square corners, in general a good agreement is achieved. Regarding the drag coefficients, they are compared in the next figure:
Again, a good agreement between the SPH and the FDM solutions is achieved, even thought SPH tends to overstimate the drag coefficient.