DNS 1-5
Lib:Flow over a rounded step
Abstract
The HiFi-TURB-DLR rounded step test case is designed to investigate the effect of an adverse pressure gradient on a turbulent boundary layer. The problem considers the flow over a 2D rounded step, see Fig. 1, and is inspired by the axisymmetric rounded step proposed by Disotell and Rumsey [1,2,3].
This test case concerns a highly resolved Direct Numerical Simulation (DNS) using the high-order discontinuous Galerkin (DG) code MIGALE [4]. The code couples the DG space discretization with a high-order implicit time integration, which relies on Rosenbrock schemes.
The primary objective of this contribution is to provide a rich database of flow and turbulence statistics as a reference target for verification and validation of RANS models based subsequent computational campaigns (see UFR 3-35 Test Case).
The provided statistical quantities in the database are:
- mean pressure and velocity components;
- Reynolds stress components;
- pressure autocorrelation;
- velocity triple correlation;
- pressure-velocity correlation;
- Taylor microscale;
- Kolmogorov length and time scales;
Notice that the solver discretize the compressible Navier--Stokes equations. Accordingly, density and temperature fields, as well their gradients have been collected during the computational campaign. However, since the flow regime is incompressible (), these fields are a side product of this contribution and thus are not reported.
Figure 1: Rounded step case, Re=78490. Dimensionless instantaneous streamwise velocity at midspan using MIGALE with DG P3 (~300 million DoF/eqn). |
References
[1] K. J. Disotell and C. L. Rumsey, "Modern CFD validation of turbulent flow separation on axisymmetric afterbodies"
[2] K. J. Disotell and C. L. Rumsey, "Development of an axisymmetric afterbody test case for turbulent flow separation validation", NASA/TM-2017219680, Langley Research Center, Hampton, Virginia, 2017
[3] E. Alaya, C. Grabe, T. Knopp, "Design of a parametrized numerical experiment for a 2D turbulent boundary layer flow with varying adverse pressure gradient and separation behaviour", DLR-Interner Bericht. DLR-IB-AS-GO-2020-109. DLR Institute of Aerodynamics and Flow Technology, 2021
[4] Bassi, F., Botti, L., Colombo, A. C, Ghidoni, A., Massa, F., "On the development of an implicit high-order Discontinuous Galerkin method for DNS and implicit LES of turbulent flows”, European Journal of Mechanics, B/Fluids, 2016
Contributed by: Francesco Bassi, Alessandro Colombo, Francesco Carlo Massa — Università degli studi di Bergamo (UniBG)
© copyright ERCOFTAC 2024