Wind Tunnel renovation, flow verification and flapping wing analysis.

Abstract

The Naval Postgraduate School (NPS) Micro-Air Vehicle (MAV) wind tunnel was refurbished in this study. This wind tunnel has a 61 by 38 centimeter test section with a contraction ratio of 6.75, and testing speeds up to 9 meters per second (m/s). The objectives of this work were to create a high quality, customized facility for further MAV study, and to fully characterize the wake of the MAV at a plane downstream of the model. Extensive repairs were made to the wind tunnel intake, test section, and fan. The flow field produced in the tunnel was analyzed with hot wire anemometry. The turbulence intensity ranged from .7% to .5% for freestream velocities of 2 m/s to 5 m/s. The velocity variation across the test section ranged from .251% to .125%. A model of the NPS MAV was placed in the test section and the wake was studied with and without the main wing, and in vertical and horizontal orientations. The wake was characterized with hot wire anemometry and flow visualization techniques at various flapping frequencies and freestream velocities.