Van der Westhuizen, Jacob E.Dirker, JacoMeyer, Josua P.2017-03-302016-05J. E. van der Westhuizen, J. Dirker & J. P. Meyer (2016) Implementation of Liquid Crystal Thermography to Determine Wall Temperatures and Heat Transfer Coefficients in a Tube-in-tube Heat Exchanger, Experimental Heat Transfer, 29:5, 632-656, DOI: 10.1080/08916152.2015.1065294.0891-6152 (print)1521-0480 (online)10.1080/08916152.2015.1065294http://hdl.handle.net/2263/59576Liquid crystal thermography was used in a water-operated concentric tube-in-tube heat exchanger to determine local annular heat transfer coefficients at the inlet region. An annular diameter ratio of 0.54 was considered with the inlet and outlet orientated perpendicularly to the axial flow direction. Both heated and cooled cases were considered at annular Reynolds numbers ranging from 1000 to 13 800. Wall temperature distributions were directly measured by means of a coating of thermo-chromic liquid crystals. Local heat transfer coefficients at the inlet were higher than those predicted by most correlations, but good agreement was obtained with some literature.en© Taylor & Francis Group, LLC. This is an electronic version of an article published in Experimental Heat Transfer, vol. 29, no. 5, pp. 632-656, 2016. doi : 10.1080/08916152.2015.1065294. Experimental Heat Transfer is available online at : http://www.tandfonline.com/loi/ueht20.Liquid crystal thermographyExperimental methodHeat transfer coefficientsDeveloping inlet regionEngineering, built environment and information technology articles SDG-07SDG-07: Affordable and clean energyEngineering, built environment and information technology articles SDG-09SDG-09: Industry, innovation and infrastructureEngineering, built environment and information technology articles SDG-12SDG-12: Responsible consumption and productionPostprint Article