High-resolution time-dependent numerical simulations are used to investigate the effect of thickness ratio on fluid flow and heat transfer performance in multi-louvered fins. Results for three fin thickness ratios, two louver angles, and a fin pitch to louver pitch ratio of one are reported for Reynolds number ranging from 50 to 1200. Thickness ratio is found to have a significant effect on flow efficiency, especially in geometries with small louver angles. For small louver angles, increasing thickness to louver pitch ratio from 0.05 to 0.15, decreases the flow efficiency by as much as 35–40%. As expected, increasing thickness ratio increases total pressure drop, most of which results from an increase in form drag. Heat transfer coefficient, on the other hand, is not influenced strongly by the thickness ratio. The increase in flow acceleration and local Reynolds number with increase in thickness ratio, on one hand, is offset by low flow efficiencies and recirculation zones on the other. As a consequence, some heat transfer degradation is found at low Reynolds numbers, however the degradation diminishes as the Reynolds number increases beyond 300. In general, larger thickness ratios lead to a lower ratio of j/f.

This content is only available via PDF.
You do not currently have access to this content.