Deformation and Breakup of Water Droplets near an Airfoil Leading Edge

Abstract

Thisworkpresents the results of an experimental study on droplet deformation and breakupnear the leading edge of an airfoil. The experiment was conducted in the rotating rig test cell at the National Institute of Aerospace Technology (INTA) inMadrid, Spain. An airfoil model placed at the end of the rotating armwas moved at speeds of 50 to 90 m=s. Amonosized droplet generatorwas employed to produce droplets that were allowed to fall fromabove, perpendicular to the path of the airfoil at a given location. High-speed imaging was employed to observe the interaction between the droplets and the airfoil. The high-speed imaging allowed observation of droplet deformation and breakup as the droplet approached the airfoil near the stagnation line. A tracking software programwas used to measure, from the high-speed movies, the horizontal and vertical displacement of the droplet against time. The velocity, acceleration,Weber number, Bond number, Reynolds number, and drag coefficients were calculated along the path of a given droplet from the beginning of the deformation to the breakup and/or hitting of the airfoil. Results are presented for droplets with a diameter of 490 m at airfoil speeds of 50, 60, 70, 80, and 90 m=s.