Acoustic Attenuation and Relaxation Phenomena in Steam at High Temperature and Pressure

Abstract

The purpose of this investigation is the measurement of ultrasonic attenuation in steam at high temperatures and at pressures above atmospheric in the search for possible relaxation mechanisms. An acoustic fixed path interferometer has been constructed to allow attenuation measurements up to temperatures of the order of 450 deg C and pressures around 100 atmospheres. Relaxation peaks have been identified in the pressure range from 1 to 10 atmospheres and over the temperature range from 235 to 400 deg C. These correspond to relaxation times of the order of 2 × 10−8 sec, which is probably too small to be of significance in the high-speed flow properties of steam under extreme conditions. The results reported here are in order of magnitude agreement with those obtained by Huber and Kantrowitz using the impact tube method.