Experimental Research on Ice Density Measurement Method Based on Ultrasonic Waves

Ice density is an important physical parameter affecting the mechanical properties of ice. Due to bad field environments, the traditional density measurement method cannot achieve continuous monitoring of ice density. Therefore, the authors of this paper propose a new idea: to use the acoustic characteristics of ice to obtain ice density. The acoustic and physical properties of artificially frozen ice samples, with salinity values in the range of 0 similar to 8.5 parts per thousand, were tested using a nonlinear high-energy ultrasonic testing system to explore the relationships among ice density, sound velocity, temperature, and salinity when the temperatures of the ice samples rose from -30 degrees C to -5 degrees C. The test results show that the freshwater ice density decreases from 915.5 kg/m(3) to 911.9 kg/m(3) when the ice temperature rises from -30 degrees C to -5 degrees C. The density of saltwater ice varies from 899.8 kg/m3 to 912.9 kg/m(3). When the salinity remains the same, the density of an ice sample decreases with an increase in temperature and increases with an increase in sound velocity. When the ice temperature remains the same, the density of saltwater ice increases with an increase in salinity and decreases with an increase in sound velocity. Based on the test results, a prediction model of ice density with respect to sound velocity, temperature, and salinity is established. The root mean square error between the predicted values of the model and the measured values is 0.337 kg/m(3), indicating that the prediction accuracy is high.