Direct numerical simulation of the Gaussian (Boeing) Bump: Separated flow region

Direct Numerical Simulation of a turbulent boundary layer over the Gaussian (Boeing) bump is performed at ReL = 2 million (based on the tunnel width L which corresponds to Reh=170,000 based on the bump height). This simulation will be contrasted with prior published results at ReL=1 million case (same geometry at half the speed) where the flow did not separate due to re-laminarization and re-transition. At 2 million the flow remains turbulent and separates soon after the onset of a strong adverse pressure gradient just past the bump apex. Velocity, Reynolds stresses, spectra, and turbulent kinetic energy budgets from the post-separation region of the flow will be presented and discussed. In this region, we also analyze the flow in a streamline-aligned coordinate system to better understand its flow physics.