Experiments were conducted in a recirculating water channel to determine the flow topology around a simplified two-wheel landing gear model. Both hydrogen bubble visualization and Particle Image Velocimetry techniques were employed. The Reynolds number based on wheel diameter was 32,500. The general flow topology was characterized for several wheel configurations. Previously undiscovered structures have been found in several regions of the flow field, and their behavior was found to depend strongly on the geometry of the wheels. The phenomena of vorticity amplification near the stagnation point of the wheels was also studied. Weak upstream vorticity was found to collect, grow, and amplify into large coherent structures which then shed in a regular manner. The size, location, and shedding frequency of these structures has been characterized. The impingement point of the upstream vorticity was found to dictate the dynamics of the phenomena.

Experiments were conducted in a recirculating water channel to determine the flow topology around a simplified two-wheel landing gear model. Both hydrogen bubble visualization and Particle Image Velocimetry techniques were employed. The Reynolds number based on wheel diameter was 32,500. The general flow topology was characterized for several wheel configurations. Previously undiscovered structures have been found in several regions of the flow field, and their behavior was found to depend strongly on the geometry of the wheels. The phenomena of vorticity amplification near the stagnation point of the wheels was also studied. Weak upstream vorticity was found to collect, grow, and amplify into large coherent structures which then shed in a regular manner. The size, location, and shedding frequency of these structures has been characterized. The impingement point of the upstream vorticity was found to dictate the dynamics of the phenomena.