Insufficient compatibility of cavitation resistance assessments based on laboratory tests conducted under different cavitation conditions is generally considered a major methodological difficulty whenever quantitative prediction of material performance under field conditions is attempted. The present paper reports a substantial progress made recently by the authors in their efforts to develop the procedure of cavitation erosion resistance assessment yielding compatible results even in case of experimental tests having been conducted at rigs of different design and principle of operation. The approach developed assumes that the material resistance to cavitation may be described satisfactorily by its response to individual fractions of cavitation pulses amplitude distribution. The backbone of the approach is a differential superposition law, which allows modelling erosion progress under polyfractional cavitation load by keeping continuous control over erosive process inputs contributed by individual fractions of cavitation pulses distribution. The model developed allows determining reference material resistance to individual load fractions basing on laboratory tests conducted under several specified cavitation conditions, determining the effective load distribution at an arbitrary rig basing on erosion tests of a set of reference materials and predicting the structural material performance in the field, provided the load distribution has been previously established.
The general concept of the approach was already presented during the ICEAW conferences in 1999 and 2003. Now, numerical codes and some preliminary results are also available. Further progress requires enhancing experimental technique of cavitation pulses measurement under laboratory conditions. An action plan aimed at full validation of the method and its implementation into laboratory practice is presented in the end of the paper.