Friction factors of power-law fluids in chevron-type plate heat exchangers

• Published in: Journal of food engineering Vol. 89; no. 4; pp. 441 - 447
• Main Authors: Fernandes, Carla S., Dias, Ricardo P., Nóbrega, João M., Maia, João M.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.12.2008; [New York, NY]: Elsevier Science Pub. Co; Elsevier
• Subjects: Beta; Biological and medical sciences; Coefficients; Computational fluid dynamics; Fluid flow; fluid mechanics; Fluids; Food engineering; Food industries; food processing equipment; foods; friction; Friction factor; Fundamental and applied biological sciences. Psychology; General aspects; Generalised Reynolds number; ion transport; mathematical models; mechanics; Non Newtonian fluids; Plate heat exchangers; Power-law fluids; processing technology; simulation models; Tortuosity; Plate heat exchangers; Friction factor; Generalised Reynolds number; Power-law fluids; Tortuosity; Heat; Friction; Plate heat exchangers;Power-law fluids;Generalised Reynolds number;Friction factor;Tortuosity; Plate heat exchanger; Power
• ISSN: 0260-8774; 1873-5770
• DOI: 10.1016/j.jfoodeng.2008.05.022

In the present work laminar flows of Newtonian and power-law fluids through cross-corrugated chevron-type plate heat exchangers (PHEs) are numerically studied in terms of the geometry of the channels. The plates area enlargement factor was a typical one (1.17), the corrugation angle, β, varied between 30° and 60° and the flow index behaviour, n, between 0.25 and 1. Single friction curves fRe g = K for both Newtonian and non-Newtonian fluids are proposed for each β by developing an adequate definition of the generalised Reynolds number, Re g. The coefficient K compares well with experimental data, for all (seven) values of β, and depends on the tortuosity coefficient, τ. It was found that, for each β, τ decreases with the decrease of n. Food fluids are frequently processed in PHEs and usually behave as non-Newtonian fluids. This study can be useful in engineering applications as well as in the characterization of transport phenomena in PHEs.