Ultrasonic measurement of convective heat transfer coefficients on a nonuniform melt layer

Abstract

This article describes a new ultrasonic measurement technique that evaluates local convective heat transfer coefficients on a curved, melting layer of ice based on measured time-of-flight data. A 2.25 MHz dual element transducer was used to measure the time-dependent thickness of a nonuniform layer of ice that was rapidly melting. The instantaneous thickness data were used to determine the velocity and slope of the ice/water interface and this information was converted into local, instantaneous heat transfer rates at the melt surface. The application of an ultrasonic technique to the measurement of heat transfer rates is unique because it is the first time that thickness measurements on a curved surface that is continually varying in shape have been used to determine local convective heat transfer coefficients.