Simulation and Analysis of Natural Rain in a Wind Tunnel via Digital Image Processing Techniques

摘要

It is desired to simulate natural rain in audwind tunnel in order to investigate its influenceudon the aerodynamic characteristics of aircraft.udRain simulation nozzles have been developed andudtested at JPL. Pulsed laser sheet illumination isudused to photograph the droplets in the movingudairstream. Digital image processing techniques areudapplied to these photographs for calculation ofudrain statistics to evaluate the performance of theudnozzles. It is found that fixed hypodermic typeudnozzles inject too much water to simulate naturaludrain conditions. A modification uses two aerodynamicudspinners to flex a tube in a pseudo-randomudfashion to distribute the water over a larger area.