The use of liquid crystal thermography and particle image velocimetry in the exploration of heat transfer measurements

Abstract

-Generation of vortices enhances heat transfer by swirl, flow destabilization and development of viscous layers. They may increase heat transfer by several hundred percent. Prior to the use of vortices to influence heat transfer it must be known how different vortices are generated and controlled, and how they interact with the base flow and temperature field. To select the most appropriate vortex generators (VG) for a given task it is necessary to know the heat transfer and flow losses associated with the generation of a specific vortex system. The aim of the paper is to asses the state of art and to encourage exploration of heat transfer control by vortices. Flow visualization and heat transfer experiments were conducted using an open low-speed wind tunnel equipped with Liquid Crystals Thermography (LCT) and Particle Image Velocimetry (PIV). In this work we consider five types of transverse vortex generators (TVGs) which where brought to required temperatures by the hot film method. Heat transfer measurements were carried out by LCT.

Modeling of Passive and Forced Convection Heat Transfer in Channels with Rib Turbulators

“…Furthermore, liquid crystal thermography assisted by particle image velocimetry is an excellent and recognized measurement method used in the study of advanced thermal-flow processes in major world-wide research centers [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31].…”