Large eddy simulation of the turbulent flow past a backward-facing step with heat transfer and property variations

✍ Scribed by Ravikanth V.R. Avancha; Richard H. Pletcher

• Publisher: Elsevier Science
• Year: 2002
• Tongue: English
• Weight: 462 KB
• Volume: 23
• Category: Article
• ISSN: 0142-727X
• DOI: 10.1016/s0142-727x(02)00156-x

✦ Synopsis

The heat transfer and fluid mechanics of a turbulent separating and reattaching flow past a backward-facing step are studied using large eddy simulation. A fully coupled, collocated-grid, low-Mach number preconditioned, compressible formulation employing central differences was developed to conduct the simulations. A sixth order compact filter was used to prevent pressurevelocity decoupling. A dynamic sub-grid scale procedure employing the compressible version of the Smagorinsky model has been used to capture the effects of the small scales. The isothermal turbulent flow past the step, at a Reynolds number of 5540 (based on the step height and upstream centerline velocity) and a Mach number of 0.006, was simulated to validate the formulation. Subsequently, the bottom wall downstream of the step was supplied with a uniform wall heat flux; three simulations with increasing heat flux levels were conducted. The viscous sub-layer played a critical role in controlling the heat transfer rate. Streamwise and wallnormal turbulent heat fluxes were of the same order of magnitude. The Reynolds analogy did not hold in the recirculation region. However, the Stanton number profiles showed a striking similarity with the fluctuating skin-friction profiles.