A New Approach for Determination of Cavitation Sensitivity of Water Available to Purchase

The conditions for the appearance of cavitation, i.e. the local vaporization of fluid under static or dynamic stresses, are closely connected with the tensile strength of the fluid (Arndt, Keller (1992)). Although the dominant effect of water quality on the cavitation interception has been known for many years (Keller (1981, 1983, 1984)), it is uncommon to measure its stress resistance. A possible reason for that could be the unique stress-resistance probe of Keller (1987, 1994) (Eickmann (1992)), which by itself represents a great engineering break-through, is rather complex and expensive. It has become clear during the ASME/JASME conference in San Francisco, 1999 (Keller, Rott, Striedinger, Awad, Ludwig, Yang, Li), and the Fourth International Symposium on Cavitation in Pasadena 2001 (Keller), that internationally standardized testing conditions are required with respect to water quality (Heller (2000)). A relatively simple method of concurrently measuring tensile strength or cavitation susceptibility in cavitation channels has been developed at the Institute of Fluid Mechanics of the Technische Universita¨t Dresden during the last months. This newly developed tensile strength measuring technique is not only efficient and cheap but can also be installed in any existing cavitation channel with comparably small effort. The presented paper represents the actual developmentstate of the Dresden measuring device. Comparison measurements at the cavitatio n-channels of the Versuchsanstalt Obernach (Dr. Keller), Schiffsbau-Versuchsanstalt Potsdam (Mr. Heinke) and the Schiffsbau-Versuchsanstalt Hamburg (Mr. Friesch) are planed for the following months.