This study looks at a turbulent round jet impinging on a heated convex hemispherical surface. Numerical simulation of the flow and heat transfer process is performed using the commercial Computational Fluid Dynamics software FLUENT. The fluid domain is divided into a large number of small cells over which the governing partial differential equations of fluid dynamics are discretized. The result is a set of linear algebraic equations which are solvable on a computer. This study differentiates itself from other studies by using the Large Eddy Simulation (LES) turbulence model rather than the traditional Reynolds Averaged Navier-Stokes (RANS) model. RANS resolves only the averages of flow properties. LES filters the flow properties instead of averaging them. The filter resolves a greater range of the flow properties than an average, allowing for more accurate solutions. The underlying assumption behind LES is that turbulence is caused by tiny vortices or eddies. The effect of small eddies on the flow is negligible in comparison to the effect of larger eddies, so only the large eddies need be resolved. Results are compared and validated against available experimental results to ascertain the accuracy of the turbulence models and whether the LES model provides the most accurate solution.

More >>