Wavelet analysis of experimental results for coupled structural–hydraulic behavior of the EURISOL target mock-up

During test runs of the The European Isotope Separation On-Line (EURISOL) target mock-up performed in December 2008, data were recorded for strain gages and for acceleration sensors. In this paper, the applicability of wavelet analysis for detecting the onset and the status of flow-induced cavitation is investigated for the first time. Even under noisy conditions, the detection of incipient cavitation was possible when combining measurements with data from structural and fluid dynamic simulations. The distribution of coefficients of suitably selected wavelets yields a quantitative measure for the extent of cavitation in the EURISOL target mock-up under representative flow conditions. Without cavitation, the distribution of the wavelet coefficients was Gaussian with a small standard deviation, whereas for developed cavitation the standard deviation was large and the probability density function (PDF) approached a uniform distribution.