Propeller cavitation vortices measuring equipment - uses motorised computer controlled laser emitter with photodetector receiver sensitive to presence of air bubbles

摘要

A laser emitter of parallel light (19,21) transmits a beam orthogonally across the direction of motion of the cavitation vortices (1) created by the blade tips (3) of a marine propeller (7). If the beam strikes a vortex (1) it is reflected by the cavitation bubbles. The photodetector receiver (23) may be placed directly in the path of the laser beam (21) so that it receives less light in the presence of a cavitation vortex or to one side so that it receives relatively more light due to reflection. Measurement may be automated by computer-controlled motorisation. ADVANTAGE - Equipment lends itself to automatization and statistical analysis.