Numerical Study of Chevron Jet Noise Using Parallel Flow Solver

Hybrid large-eddy type simulations for chevron nozzle jet flows are performed at Mach 0.9 and Re ∼ 106. Implicit or numerical large- eddy simulation (ILES or NLES) is employed, namely omitting explicit subgrid scale models. A Reynolds-averaged Navier-Stokes (RANS) solution is blended into the near wall region. This makes an overall hybrid LES-RANS approach. A Hamilton–Jacobi equation is applied to remove the disparate turbulence length scales implied by hybridization. Computations are contrasted for a baseline round nozzle and a highly bended chevron nozzle. The chevron effects are studied by comparing both nozzles using the same mesh resolution and flow conditions. Through the use of RANS simulations the state of the incoming boundary layer from the measurements is explored and the extent of any laminarization. Noise predictions are made using a permeable surface Ffowcs Williams – Hawkings (FWH) method based on the near field LES data. Results are compared with the NASA SHJAR measurement data. Parallel aspects of the flow solver are also explored including an improved data packaging/sending mechanism using scheduling.