Shadowgraphs Of Helicopter-Rotor-Tip Vortexes
Optical apparatus produces full-scale or larger shadowgraph of tip vortexes of helicopter rotor. Stroboscope projects shadow image of helicopter rotor on large, square screen. Commercial, highly reflecting projection screen used; simply projecting image on white wall does not yield enough light for photographing vortexes with standard 35-mm camera. Apparatus adapts to use in large wind tunnels.
Parthasarathy, Shakkottai P.↗