APPLICATION OF THE AUTO- AND CROSS-POWER SPECTRA TO HYDRO- AND AEROACOUSTICS

This paper is concerned with the study of pressure and flow rate fluctuations propagation within ducts and hydraulic components. The description of the behaviour of such components is based on the transfer method. This mathematical description gives the input–output relationship of a system. An inverse method is used to identify this transfer matrix according to experimental data. Several pressure transducers are located on the test rig to seek the state vector or relationship between the inlet and the outlet of the component (i.e. pump) according to acoustic intensity techniques. This method requires averaging and phase matching. Autopower spectrum and crosspower spectrum functions are used during the tests in order to get experimental data on the pressure signal in different cross-sections of the pipes. This study aims at validated experimental techniques, which can be used to get the transfer matrix of piping systems. Different experimental results are given from tests performed in air as well as in water.