%0 Journal Article %A Paleebut , Ayudh Mapairoje %A Kittichaikarn, Chawalit %D 2010 %I Begell House %K thermochromic liquid crystals, local heat transfer coefficient, rectangular duct, swirler, image processing %N 3 %P 255-266 %R 10.1615/JFlowVisImageProc.v17.i3.60 %T THE EFFECT OF A SWIRLER ON THE HEAT TRANSFER COEFFICIENT OF FLOW IN A RECTANGULAR DUCT USING THERMOCHROMIC LIQUID CRYSTALS %U https://www.dl.begellhouse.com/journals/52b74bd3689ab10b,6bfbd93509947e2e,062b789c703b2a28.html %V 17 %X This paper presents a study on the heat transfer coefficient of flow in a rectangular duct with a swirler using thermochromic liquid crystals. The experiments were conducted in the purpose- built perspex rectangular duct with an aspect ratio of 1:5. One side of the duct was heated by an electrical heater which generated a uniform constant heat flux over the surface. The variation of the Reynolds number was 13,000−24,000. Thermochromic liquid crystals were sprayed on the top of the duct surface forming a temperature sensitive layer. Swirlers with vane angles of 30°, 45°, and 60° to the flow axis were used in the experiment. From the results obtained, it was found that the thermal performance of the air flow through the rectangular duct with a 60°−swirler is the best among those used in this study. %8 2010-11-12