Simulation of Transient Dynamics of Shock Wave Boundary Layer Interactions Using Hybrid Large-Eddy/Reynolds-Averaged Navier-Stokes Models

Abstract

Public Reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comment regarding this burden estimates or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302, and 49624.1-EG-IISimulations of the Mach 5 compression-corner shock / turbulent boundary layer interaction experimentally mapped by Prof. David Dolling and co-workers have been performed using a hybrid large-eddy / Reynolds-averaged Navier-Stokes (LES/RANS) model. The model captures the mean-flow structure of the interaction reasonably well, with observed deficiencies traced to an underprediction of the displacement effects of the shock-induced separation region. The computational results provide some support for a recent theory relating to the underlying causes of low-frequency shock wave oscillation. The simulation results indicate that the sustained presence of a collection of neighboring streaks of low / high momentum fluid within the boundary layer induces a lowfrequency undulation of the separation front. Power spectra obtained at various streamwise stations are in good agreement with experimental results, indicating that the LES/RANS method is capable of predicting both the low and high-frequency dynamics of the interaction. Downstream of re-attachment, the simulations capture a three-dimensional mean flow structure, dominated by counter-rotating vortices that produce wide variations in the surface skin friction. Predictions of the structure of the re-attaching boundary layer agree well with experimental pitot pressure measurements. In comparison with Reynolds-averaged model predictions, the LES/RANS model predicts more amplification of Reynolds stresses and a broadening of the Reynolds-stress distribution within the boundary layer that is probably due to re-attachment shock motion.40 hybrid large-eddy / Reynolds-averaged Navier-Stokes simulations, shock wave / turbulent boundary layer interaction, shock system dynamics Project Abstract (Original Proposal)Many experimental investigations have noted that complex shock / boundary layer interactions exhibit large-scale, low frequency motion that is distinct from that associated from wall-layer turbulence. This motion results in fluctuating pressure and heat-transfer loads that can adversely affect the performance of supersonic missile systems, among others. Accurate predictions of such effects would appear to require a time-dependent modeling strategy, such as large-eddy simulation (LES) or direct numerical simulation (DNS). The application of these techniques to flows at practical Reynolds numbers requires immense computational resources, and as yet, very few studies have...

Prediction of Vortex Initiation using an Unsteady Panel Method with an Integral-Boundary-Layer Calculation

“…NCSU's REACTMB-INS [24,25] solver is used for the computational fluid dynamics (CFD) calculations performed in this study. The governing equations are written in arbitrary Lagrangian/Eulerian form, which enables the motion of a body-fitted computational mesh in accord with prescribed rate laws.…”

Computation of viscous flow characteristics of a supersonic intake using eddy-viscosity turbulence models

“…To demonstrate this, several modeling and validation studies have been carried out. In the recent years, as a result of the improvement in computational facilities, the DNS, LES, or hybrid RANS modeling strategies are becoming attractive to capture the SWBLIs in canonical geometries like compression corner [16][17][18] and the pseudo-shock structure of normal SWBLIs in a duct. 19 Though, DNS/ LES studies have shown to capture the characteristics of SWBLIs quite accurately, it requires huge computational resources.…”