Experimental studies of heat transfer and fluid flow across corrugated-undulated heat exchanger surfaces

Experimental and numerical investigation of thermal -hydraulic performance in wavy fin-and-flat tube heat exchangers

“…In the tested range of Re ¼ 1000e5500, for the 2A ¼ 2.0 mm, the j factor is large than that of the 2A ¼ 1.5 mm and 2A ¼ 1.0 mm 5.8% and 11.4%, while the f factor is larger than 39% and 83.7%. The results are in good agreement with experiment results of Stasiek [25], who reported that the Nusselt number average increase by 80% for the undulation angles ranging from 20 to 70 , friction factor increases by 3 times.…”

Recent Developments in High Temperature Heat Exchangers: A Review

“…The fluid-separating plates of these heat exchangers are typically manufactured by compression processing of a thin metal sheet, and they come in several patterns such as wavy, chevron, washboard, herringbone, cross-corrugated, cross-undulated, or crosswavy (Utriainen and Sundén, 2002;Stasiek, 1998;McDonald, 2000;Foerster and Kleemann, 1978). Two such heat transfer plates are then stacked to produce a single cell, and this process is repeated to manufacture the required number of cells.…”

Liquid crystal technique application for heat transfer investigation in a fin-tube heat exchanger element

“…The contours of constant heat transfer coefficient are not directly equivalent to the isotherms, as measured from the images. They are determined after taking into account thermal conduction in the plate, radiation from the surface and other corrections, which is typically about 5% of the net flux (Hollingsworth et al, 1989;Stasiek, 1998). The liquid crystal colour temperature T, is 35.5°C, some 9.5°C below the air temperature (T, = 45°C) for these experiments.…”

“…A great majority of applications that use colour image processing do so because colour is the most important and obvious feature of the images they are examining. These new tools (liquid crystals, computers and image processing) have come together during the past few years to produce a powerful new examination technique: true-colour digital processing of liquid crystal images to yield full-field temperature, velocity and heat transfer coefficient distribution (Hollingsworth et al, 1989;Stasiek, 1998;Stasiek and Collins, 1996). Now, new and more incisive experiments are being settled in conventional situations, while those which have been previously intractable can also be studied.…”