Influence of Turbulence Modeling on the Broadband Noise Simulation for Complex Flows

Abstract

The investigations presented are related to the evaluation of turbulence modeling on the prediction of broadband noise generated by the complex flow past a rod‐airfoil configuration. The unsteady flow simulation is based on the Reynolds‐averaged Navier‐Stokes (RANS) equations as well as on a Large Eddy Simulation (LES). In addition a hybrid approach of both methods, the Detached Eddy Simulation (DES) which has recently been developed for complex flow configurations considered using dierent turbulence models. Far‐field noise is calculated using the classical aeroacoustic analogy of Ffowcs‐Williams & Hawkings (FWH). The comparison are performed for a NACA0012 airfoil located in the wake of the rod at a subcritical vortex shedding regime. The investigations demonstrate the dierent ability of the various turbulence model approaches as well as of the numerical schemes applied with respect to the simulation of broadband noise. Compared to the experimental values the DES results are in reasonable agreement for frequencies up to 4000 Hz, but clearly indicate the influence of the turbulence model applied. Using k‐ model for DES method results in the more accurate prediction of the shedding frequency in comparison to the SA‐DES. The spectral content of the flow, such as broadening of the main Strouhal peak and overall broadband spectrum, is reproduced well from all DES simulations, as the DES captures the main flow physics and turbulent scales in wake of the rod in the LES mode.