Rib spacing effect on heat transfer and pressure loss in a rectangular channel with semicircular ribs

Abstract EN

Ribs of various shapes are used for heat transfer enhancement, but its performance significantly depends on geometrical features and flow conditions.

This study experimentally finds out the influence of rib spacing, and semicircular shape ribs with three-rib spacing ratio (P/e) = 8, 10, and 12 are studied and located on lower wall of the rectangular channel.

Reynolds numbers varied from 10000 to 29,000 and the blockage ratio of the channel (e/Dh) was 0.151.

The results show that semicircular rib performed better than plain plate, but more friction is found.

Semicircular rib with rib spacing of 50 mm (P/e =10) shows highest thermal performance, enhanced by an average of 39 % heat transfer than rib spacing of 40 and 60 mm (P/e=8 and 12).

Friction losses were observed to be the highest in rib spacing ratio of 8 and found an average of 10 % more friction compared to rib spacing ratio of 10 and 12.

Semicircular rib with spacing ratio 8 shows the least thermal performances compared to other configurations.