Study of turbulent flow past a square cylinder using partially-averaged Navier–Stokes method in OpenFOAM

Abstract

<jats:p> The present paper reports numerical simulation of turbulent flow over a square cylinder using a novel scale resolving computational fluid dynamics technique named Partially-Averaged Navier–Stokes (PANS), which bridges Reynolds-Averaged Navier–Stokes (RANS) with Direct Numerical Simulation (DNS) in a seamless manner. All stream-wise and wall normal mean velocity components, turbulent stresses behavior have been computed along the flow (streamwise) as well as in transverse (wall normal) direction. The measurement locations are chosen based on the previous studies so that results could be compared. However, the Reynolds number ( Re) of the flow is maintained at 21,400 and K– ω turbulence model is considered for the present case. All the computations are performed in OpenFOAM framework using a finite volume solver. Additionally, turbulent kinetic energy variations are presented over a wide range of measurement planes in order to explain the energy transfer process in highly unsteady turbulent flow field. The fluctuating root mean square velocities in the streamwise as well as in the wall normal direction have been discussed in the present work. It has been found that Partially-Averaged Navier–Stokes (PANS) model is capable of capturing the properties of highly unsteady turbulent flows and gives better results than Reynolds-Averaged Navier–Stokes (RANS). The results obtained using Partially-Averaged Navier–Stokes (PANS) are quite comparable with Large Eddy Simulation (LES) and Direct Numerical Simulation (DNS) data available in literature. The partially-averaged Navier–Stokes results are compared with our simulated Reynolds-Averaged Navier–Stokes (RANS) results, available experimental as well as numerical results in literature and it is found to be good in agreement. </jats:p>

The hydrodynamic analysis of multiple hydrofoils translating in tandem in presence of a free surface

“…As the angle of attack of downstream hydrofoil increases, it was observed that free surface waves become more non-linear. For the simulated highly nonlinear cases, the wave steepness ratio is found to be the order of 0.2618 for 2°of angle of attack and 0.3979 for 8°of angle of attack as calculated in equations ( 5) and (6).…”

“…In Einstein notation, the unsteady RANS equations for three-dimensional, unsteady turbulent flow of an incompressible fluid can be written as 6,34,35,41 :…”

“…The works on the hydrodynamics of hydrofoils and other bluff bodies in unbounded fluids are aplenty 1–7 that include boundary effects, while the literature in particular of the free surface are comparatively scanty. The facts that foil-free surface and foil-foil interactions could have significant effect on the performance of hydrofoil vessels and the research carried out in this area is not exhaustive, thus it has motivated our pursuit of the research reported in this paper.…”

“…The works on the hydrodynamics of hydrofoils and other bluff bodies in unbounded fluids are aplenty [1][2][3][4][5][6][7] that include boundary effects, while the literature in particular of the free surface are comparatively scanty.…”

Advances in Numerical Data Visualization of Flow around a Square Cylinder

“…These examples include three types of models, namely, 2D unsteady Reynolds-averaged simulations (URANS), 3D LES/RAS, and 3D improved delayed detached eddy simulations (IDDES) [18]. Moreover, the following techniques provide added elements to the discussion: the Spalart-Allmaras model and DES [19], LES and the Smagorinsky model [20][21][22], VLES [23], and partially averaged Navier-Stokes (PANS) simulations [24,25].…”