A comparison of physics- And correlation-based turbulence models at low reynolds numbers

The three-dimensional unsteady Reynolds-averaged Navier-Stokes k-omega-Shear Stress Transport Langtry- Menter (SSTLM) and kT - kL - ω turbulence models were studied to understand their application and transition prediction capability for incompressible flow regimes. Additionally, a novel protocol is presented for systematically studying the near-wall flow physics over a sharp trailing-edged SD7003 airfoil subjected to flow with varying freestream intensities and angles of attack and at three chord-based Reynolds numbers of 6 × 10⁴, 6 × 10⁵, and 6 × 10⁶. A complex low-Reynolds-number near-wall flow phenomenon known as the formation and destruction of the laminar separation bubble, eventually leading to flow transition from the laminar to the turbulent regimes, was resolved using both turbulence models; and their accuracy was compared with implicit large-eddy simulation surface pressure predictions. Mean and instantaneous flowfields were extracted, thus leading to a more thorough quantitative and qualitative comparison. Considering all flow characteristics, the correlation-based κ - ω - SSTLM turbulence model was shown to predict more reasonable flow transition characteristics for simple airfoil configurations.