This contribution deals with the heat transfer parameters and pressure losses in heat exchange sets with six geometrical arrangements at low Re values (Re from 476 to 2926). Geometrical arrangements were characterised by the h/H ratio ranging from 0.2 to 1.0. The experiments used the holographic interferometry method in real time. This method enables visible and quantitative evaluations of images of temperature fields in the examined heat exchange. These images are used to determine the local and mean heat transfer parameters. The obtained data were used to determine the Colburn j-factor and the friction coefficient f. The measured values show that by using the profiled heat exchange surfaces and inserting regulating tubes, an intensification of heat transfer (increase of Num, and/or j) was achieved. However, pressure losses recorded a significant increase (increase of f).
Beketova A.K., Belozerov A.F., Berezkin A.N., 1979. Golograficheskaya interfrometriya fazovykh ob´ektov/ Holografická interferometria fázových objektov. Izdateľstvo Nauka (in Russian).
Cernecky J., Koniar J., Brodnianska Z., 2012. Možnosti optimalizácie tvaru teplovýmenných plôch výmenníkov tepla s využitím experimentálnych metód a fyzikálneho modelovania. Vedecká monografia. Zvolen: Vydavateľstvo TU vo Zvolene (in Slovak).
Cernecky J., Pivarciova E., 2006. Possibilities and prospects of holography. Russia: Izhevsk State Technical University.
Financed by the National Centre for Research and Development under grant No. SP/I/1/77065/10 by the strategic scientific research and experimental development program:
SYNAT - “Interdisciplinary System for Interactive Scientific and Scientific-Technical Information”.