Low Reynolds Number Validation Using Computational Fluid Dynamics with Application to Micro Air Vehicles

Abstract

The flow physics involved in low Reynolds number flow is investigated computationally to examine the fundamental flow properties involved with Micro Air Vehicles (MAV). Computational Fluid Dynamics (CFD) is used to validate 2-D, 3-D static and hover experimental data at Reynolds numbers around 60,000, with particular attention paid to the prediction of laminar separation bubble (LSB) on the upper surface of the airfoil. The TURNS and OVERFLOW flow solvers are used with a low Mach preconditioner to accelerate convergence. CFD results show good agreement with experimental data for lift, moment, and drag for 2-D and static 3-D validations. However, 3-D hover thrust and Figure of Merit results show less agreement and are slightly overpredicted for all measured collectives. Areas of improvement in the hover model include better vortex resolution and wake capturing to ensure that all the flow physics are accurately resolved.