Measurement of temperature and velocity fields in a heater unit by liquid crystal thermometry and particle image velocimetry

Abstract

Temperature and velocity fields in a heating unit for automobiles are measured through a model experiment in water tunnel using flow visualizations and image analysis to investigate the mixing mechanism of the flow that has passed through the heater and not passed through it inside the unit. The temperature fields are measured by the liquid crystal visualization technique combined with the field calibration using full color spline fitting technique, and the velocity fields are evaluated by a particle imaging technique with a cross-correlation algorithm. These results indicate an enhanced flow mixing at larger mix-door angles, which results in a shorter mixing distance of temperature and velocity downstream of the mix door. The enhanced flow mixing is caused by the high velocity fluctuations created by the flow separation over the mix door.