ON THE DEVELOPMENT OF LARGE EDDY SIMULATION TOOLS FOR COMPRESSIBLE JET FLOW CONFIGURATIONS

The current work addresses the numerical study of unsteady turbulent compressible flows for acroacoustic applications. A novel large eddy simulation tool is developed in order to reproduce high fidelity results of compressible jet flows which arc used for acroacoustic studies using the Ffowcs Williams and Hawkings approach. The numerical solver is an upgrade of a Reynolds-averaged Navier-Stokes code previously developed. Generally, large eddy simulations demand very dense grids. Hence, high performance computing is a requirement for such simulations. Therefore, the original framework is rewritten in Fortran 90 standards, and dynamic memory allocation and parallel computation have been added to the code. The communication between processors is performed by message passing interface protocols (MPI). The large eddy simulation formulation is written using the finite difference approach. Inviscid numerical fluxes arc calculated using a second-order accurate centered scheme with the explicit addition of artificial dissipation. A five-step second-order accurate Runge-Kutta scheme is the chosen time marching method. The classical Smagorinsky model is the chosen turbulence closure for the present work. Numerical simulations of perfectly expanded jets with Mach number equal to 1.37 and Reynolds number of the jet equal to 5 x 10(5) arc performed and presented here. Time averaged results arc compared with numerical solutions and experimental data from the literature. Moreover, the speedup and the computational performance of the code arc evaluated and discussed.