FRICTIONAL FLOW CHARACTERISTICS OF WATER FLOWING THROUGH RECTANGULAR MICROCHANNELS
X. Peng, G. Peterson, B. Wang
Oct 1, 1994
Citations
377
Citations
Quality indicators
Journal
Experimental Heat Transfer
Full text
Semantic Scholar
Key Takeaway Key Takeaway: Water flowing through rectangular microchannels exhibits frictional flow characteristics, with laminar flow transition occurring at Reynolds numbers of 200-700 and fully developed turbulent flow occurring at lower Reynolds numbers.
Abstract
Experiments were conducted to investigate the flow characteristics of water flowing through rectangular microchannels having hydraulic diameters of 0.133-0.367 mm and H/W ratios of 0.333-1. Experimental results indicated that the laminar flow transition occurred at Reynolds numbers of 200-700. This critical Re for the laminar transition was strongly affected by the hydraulic diameter, decreasing with corresponding decreases in the microchannel. In addition, the size of the transition range was diminished and fully developed turbulent flow also occurred at much lower Re. The friction behavior of both the laminar and turbulent flow was found to depart from the classical thermqfluid correlations. lite friction factor, f, was found to be proportional to Re−1.98 rather than Re for the laminar condition, and proportional to Re−1.72i for turbulent flow. The geometric parameters, hydraulic diameter, and H/W were found to be the most important parameters and had a critical effect on the flow. Generally, increasing...