IMPROVEMENT OF LIF TECHNIQUE IN TEMPERATURE MEASUREMENT OF AQUEOUS AMMONIUM CHLORIDE SOLUTION DURING SOLIDIFICATION PROCESS

In this study Two-color laser induced fluorescence (LIF) technique was used to measure the instantaneous temperature maps during uni-directional solidification of aqueous ammonium chloride. The improved temperature resolution was achieved by using two temperature sensitive dyes (fluorescein and kiton red) having opposite signs in their sensitivity. The fact that the intensity of one dye increases and the other decreases with decreasing temperature, resulted in a higher temperature sensitivity (4% K-1) in the two-color LIF two-dye approach compared to all previous implementations of the two dye approach (maximum of 1.7% K-1). Temperature fields of some of the complex flow features, such as plumes and fingers, that had not been available before were obtained and will be presented in this study.

Keywords:

two-color LIF , Temperature Measurement , Aqueous Ammonium Chloride Solution