Heat Transfer and Friction in a Low-Aspect-RatioRectangular Channel with Staggered Slit-Ribbed Walls

[摘要] Fully developed heat transfer and friction in a rectangular channel with slit-ribbed walls are examined experimentally. The slit ribs are transversely arranged on the bottom and topchannel walls in a staggered manner. Effects of rib open-area ratio (β= 24%, 37%, and 46%), rib pitch-to-height ratio(Pi/H=10,15and20), and Reynolds number(10,000≤Re≤50,000)are examined. The rib height-to-channel hydraulic diameter ratio is fixed atH/De=0.081. It is disclosed that the heat transfer coefficient for the slit-ribbed channel ishigher than that for the solid-ribbed channel, and increases with rib open-area ratio. Resultsalso show that the friction factor for the slit-ribbed channel is significantly lower than thatfor the solid-ribbed one. Moreover, the ribs with larger open-area ratios in a higher flowReynolds number condition could give the better thermal performance under the constantfriction power constraint. Roughness functions for friction and heat transfer are furtherdeveloped in terms of rib and flow parameters.

[学科分类] 力学，机械学