VIBRATION CHARACTERISTICS DUE TO CAVITATION IN STATOR ELEMENT OF AUTOMOTIVE TORQUE CONVERTER AT STALL CONDITION

Cavitation behaviors in an automotive torque converter at pump speed of 600, 700 and 800 mind at the stall condition are investigated by means of the transparent model. At the same time, the influences of cavitation on mechanical vibration are studied. As a result, at the onset of cavitation, the longitudinal corner vortex cavitation is formed at the corner between outer wall and either suction or pressure surface of stator blades. After the further decrease of charge pressure, the cavitation bubbles are observed in the flow separation region formed at the leading edge on the suction surface of stator blades. Vibration spectrum peaks are found in the wide range of frequency, which increase with the development of cavitation but then decrease with its excessive development. Discussions are made for higher and lower frequency ranges separately to understand the relation between mechanical vibrations and cavitation.