Experimental modelling and research on vibroacoustic phenomena in machines

Issues related to the development of acoustic models and
determinations of energetic balances of phenomena, which occur in machines, are
important factors both in the design of low-noise machines and in the prediction
of machine noise. The acoustic modelling of machines may be carried out using a
system of omni-directional substitute sound sources, deployed in points related
to the functional elements of machines. The parameters of these sources may be
determined using inversion methods. New indices - the energy transmission index
and the energy radiation index, have been proposed for application in the
quantitative analysis of energetic phenomena occurring in machines. Determining
these indices calls for the measurement of specific vibro-acoustic parameters of
machines, acoustic pressure levels and the vibration acceleration levels or
vibration velocities of the surfaces of selected machine elements. The paper
presents the results of experimental research in the acoustic modelling of
machines with the use of inversion methods, as well as the analysis of energetic
phenomena, which take place in machines.