DNS 1-5

Lib:Flow over a smooth bump

Front Page

Description

Computational Details

Quantification of Resolution

Statistical Data

Instantaneous Data

Storage Format

Abstract

The present test case was designed to investigate the effect of an adverse pressure gradient on a turbulent boundary layer. The problem considers the flow over a 2D smooth bump geometry, see, Fig. 1, defined at UFR_X-YZ_Test_Case and inspired by the axisymmetric one proposed by Disotell and Rumsey [1,2,3].

At the inlet a Blasius profile with Re_x=650000 for the velocity, a uniform profile for static pressure and uniform profile for total temperature are imposed. Transition to turbulence is promoted downstream by means of a local forcing term. At the outlet, a standard Dirichlet condition for the pressure is prescribed. At the upper boundary a freestream condition is set. The Reynolds number is Re= 78490 and is based on freestream properties and bump height. The flow is considered compressible with Mach number based on freestream properties equal to Ma=0.13455.

The dataset concerns the scale-resolving simulation of the turbulent flow over a smooth bump using the high-order discontinuous Galerkin (DG) code MIGALE [4]. The code couples the high-order DG spatial discretization with high-order implicit time integration using Rosenbrock-type schemes, here of the fifth order [5,6]. The primary objective of this contribution is to provide a rich database of flow and turbulence statistics for verification and validation on subsequent computational campaigns.

The provided statistical quantities in the database are:

• mean pressure, temperature, density and velocity components;
• Favre averaged velocity and temperature;
• mean shear stress and heat flux;
• Reynolds stress components;
• pressure, temperature and density autocorrelations;
• Favre velocity triple correlation;
• pressure-velocity correlation;
• Reynolds stress equations budget terms;
• Taylor microscale;
• Kolmogorov length and time scales;

WIP …

• shear stress-velocity correlation;
• Difference between the Renynolds and the Favre average.

Figure 1: Smooth bump 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

[5] Di Marzo, G., “RODAS5(4) - Méthodes de Rosenbrock d'ordre 5(4) adaptées aux problèmes différentiels-algébriques", MSc Mathematics Thesis, Faculty of Science, University of Geneva, 1993

[6] Bassi, F., Botti, L., Colombo, A., Ghidoni, A., Massa, F., “Linearly implicit Rosenbrock-type Runge-Kutta schemes applied to the Discontinuous Galerkin solution of compressible and incompressible unsteady flows”, Computers and Fluids, 2015

---

Contributed by: Francesco Bassi, Alessandro Colombo, Francesco Carlo Massa — Università degli studi di Bergamo (UniBG)

Front Page

Description

Computational Details

Quantification of Resolution

Statistical Data

Instantaneous Data

Storage Format

© copyright ERCOFTAC 2024