Temporal dependence and spatial distribution of the temperature rise in an acoustic field detected by an array thermal probe

Abstract

The temperature rise in a water bath during ultrasonic irradiation was measured using a specially designed linear array thermal probe (ATP), consisting of 48 equally spaced thermocouples embedded in a highly absorbing polymer. The temporal temperature rise on the ATP due to irradiation is described as Delta T = Delta T-sat[1 - exp(-t/tau)]. The Gaussian form of spatial temperature distribution detected by the linear ATP follows from that of the relative acoustic intensity distribution obtained by using a scanning hydrophone in the acoustic field. The Gaussian width of the spatial temperature distribution increased with the acoustic power and the exposure time.