Flow and Noise simulation of the NASA Tandem Cylinder experiment using OpenFOAM

Abstract

The NASA Tandem Cylinder experiment has been simulated for the case where the cylinders were placed 3.7 diameters apart (center-to-center). This con guration allows vortex shedding to occur in the inter-gap region between the cylinders. Two-dimensional, unsteady Reynolds averaged Navier Stokes ow simulations were performed using the OpenFOAM open source code. Simulated mean and unsteady ow results compare well with published experimental data. The major discrepancies between numerical and ex- perimental ow results can be attributed to neglecting the spanwise velocity component during simulation. Acoustic computations were made using two-dimensional ow data and a compact form of Curle's theory with spanwise and temporal statistical models that intro- duced random perturbations into the time-domain signals. The upper and lower frequency limits of the acoustic simulation method were selected using arguments based on acous- tic compactness and an estimate of near- eld acoustic e ects. Acoustic simulation results compare well with experiment about the main tone. Further improvements are necessary to broaden tones at the harmonics.