SBIR-STTR Award

It is proposed to setup a full volume 3D particle tracking velocimetry system and expand on an existing particle tracking code to obtain quantitative flow visualization of the entire flow field around an airplane model in a low speed water tunnel. The off-body flowfield data will be used to describe and model the unsteady velocity field by a finite number of elementary Rankine-vortices, which will also demonstrate vortex breakdown. It is postulated that surface pressures on the model can be derived with sufficient accuracy from the energy equation by estimating the vortex-induced pressures on the model surface. Simultaneous measurements of the global forces and moments using a classical sting balance coupled with the quantitative flow visualization will be used to create a physically representative nonlinear aerodynamic model. The ultimate goal of this program is to provide a time accurate math model for the high fidelity simulation of aircraft. It is anticipated that the model will be real time capable upon sufficient optimization of the vortex model.

Benefits:
The proposed invention has considerable commercial sales potential in the fluid mechanics research community and also for industrial aerodynamic design. The combination of real time quantitative flow visualization and integral aerodynamic force and moment measurements is unique and will stir interest in the product in sales and in service. This measurement tool will help to optimize preliminary design study and also help understand the nonlinear behavior of forces and moments in the high AOA regime of modern fighter aircraft

Keywords:
water tunnel, unsteady, modeling, flow visualization, nonlinear, aircraft, simulation, particle tracking