On the Design of Cavitation Susceptibility Meters (C.S.M.'s)
CALIFORNIA INST OF TECH PASADENA
Pagination or Media Count:
Observation of cavitation in C.S.M.s at the throat of a Venturi tube provides an ideally simple and direct method to monitor the liquid quality in terms of the concentration of unstable nuclei as a function of the applied tension. In previous work, use of C.S.M.s was limited to measurement of the tensile strength of the weakest nuclei present in the liquid. This research extends this application to determine the concentration of unstable cavitation nuclei as a function of the applied tension over a wide range so that the nuclei number distribution can be derived. Various approximation are made to construct a simplified but still representative physical model of C.S.M.s. These factors include the liquid sample initial conditions and properties, critical tension and concentration of cavitation nuclei i.e. liquid quality and required accuracy and range of the nuclei concentration measurement. The most important deductions are that 1 pressure in the cavitation region is an extremely sensitive parameter and cannot be directly measured with the necessary accuracy 2 the volume of the cavitation region must be reduced as much as possible in order to increase the applied tension without incurring large errors due to nuclei interference and 3 the time response of cavitation nuclei imposes a lower bound for the length of the cavitation region.
- Test Facilities, Equipment and Methods