Detached-Eddy Simulation Around a Forebody with Rotary Motion

Abstract

Predictions of the massively separated flow around a rectangular ogive forebody are obtained using detached-eddy simulation and from a solution of the unsteady Reynolds-averaged Navier-Stokes equations. The lengths of the forebody and aftbody are 2 and 4 times the body diameter, respectively. Angles of attack of 60 and 90 deg are considered, the Reynolds number based on freestream speed and diameter is 2.1 x 10 6 , and the freestream Mach number is 0.21. Computations of the static geometry and of the ogive undergoing prescribed rotary motion are performed on a range of meshes with grid refinement from 2.1 x 10 6 to 8.75 x 10 6 cells. flow visualizations of the instantaneous vorticity show that the detached-eddy simulation predictions exhibit an increase in the range of resolved scales with increased mesh resolution. Detached-eddy simulation predictions of the pressure distribution at axial stations along the forebody are in good agreement with measured values for both angles of attack. Unsteady Reynolds-averaged Navier-Stokes predictions of the pressure along the forebody for 90 deg angle of attack exhibit relatively strong coherence, with the resulting pressure variation different from the measured values and detached-eddy simulation results. Detached-eddy simulation predictions of the ogive experiencing rotary motion about its center are obtained for spin coefficients of 0.1 and 0.2 at 90 deg angle of attack. Agreement between the predicted and measured pressure distributions for these cases is less satisfactory compared to the static-geometry results.