Document Type : Research Article
Faculty of Engineering, Bu_Ali Sina University, Hamedan, Iran
A particular counter-current flow division has been introduced compared to the previously proposed double-pass flow arrangements to improve the thermal and hydraulic performances of the flow through two isotherm parallel plates. This particular counter-current channel has been constructed by inserting two zero thickness and impermeable flat plates within the parallel-plate channel to establish a central and two external sub-channels. Then the total flow rate has been subdivided to two streams for supplying into the central and two external sub-channels in counter-current directions. The effect of the cross section ratio on the thermal and hydraulic performances have been investigated. Two flow division regimes have also been considered. In the first flow division regime, the total flow rate has been equally supplied into the two counter-current passages. In the second one, the supplied flow rates were proportional to the areas of the sub-channel cross sections. The obtained results showed that a better thermal performance could be enhanced when the cross section of the central sub-channel was greater than the external ones. Regarding the overall performance, it has been concluded that the best performance could be enhanced when the flow and cross section were equally subdivided. In this particular case, the percent of the heat transfer enhancement compared to the single-pass channel was 50%. Meanwhile, the power consumption increment of the proposed flow arrangement significantly decreased compared to the two previously proposed double-pass arrangements. It seems that the proposed flow arrangement is better alternative for double-pass arrangement.