Application of infrared thermal testing and mathematical models for studying the temperature distributions of the high-speed waterjet

In this paper, infrared thermal testing and mathematical models for studying the temperature distributions of the high-speed waterjet in air are presented. The waterjet temperature distributions are investigated under different pressures. We describe the experiments in which we apply the infrared thermal imager to obtain the infrared thermal images of the high-speed waterjet. By denoising these infrared thermal images and fitting data, we obtain the isotherms and the temperature variation curves as a function of the distances form the nozzle outlet. In order to calculate the shear stress within the water air boundary layers, multi-phase models are developed. Due to the sophisticated patterns of the multi-component model, the numerical computation is used to obtain the velocity and temperature distribution of the waterjet. The results indicate that the temperature distributions were similar when the pressure is greater than the threshold pressure. This fact is proved by further theoretical computation and experiments data. The paper revealed that the velocity profiles were similar to the temperature profiles in the radial direction at the same cross-sections. (C) 2008 Elsevier B.V. All rights reserved.