Effects of Channel Length and Chevron Angle on Pressure Drop in the Entrance Region of Corrugated Rib Channels

Plates with corrugated walls are used in plate heat exchangers for heat transfer enhancement usually at the expense of the fluid friction. In this paper, the effects of varying channel lengths and corrugation angles on the pressure drop in corrugated rib channels are examined. Water was used as the working fluid and the Reynolds number varied over the range 400 ≤ ReDe ≤ 2,500. The test fixture is constructed from aluminum and the plates core were machined with the same corrugation depth, 1.14 mm, but with different lengths, 10.16 cm and 20.32 cm and different corrugation inclination angles, 30°, 45°, and 60°. The hydraulic diameter of the formed channel is about 2.0 mm. Experimental results show that the friction factor for the short ribbed plates is significantly higher than those of the longer ribbed plates. In addition, the pressure drop increases with an increase of the corrugation angle for all ribbed plates tested. Based on the experimental results, correlations for predicting friction factor are proposed.