Reduction of Pressure Loss of a Rectangular Block on the Wall of Parallel Channel.

Abstract

Reduction of pressure loss of a rectangular block on the wall of parallel channel was investigated by setting a rod on the wall upstream or downstream of the block. The height of the channel B was 30 mm. The side length, C, of the rectangular block was 30 and 60 mm and the height of the block, H, was from 8 to 20 mm. The mean velocity of the channel ranged from 6 to 10 m/s. The effects of the rod diameter and its position on the pressure loss coefficient ζ were measured. The reduction of pressure loss achieved 30% and 15% for a suitable upstream and downstream rod, respectively. The pressure drop on the sudden contraction reduced by the upstream rod, and the static pressure rise on the sudden expansion increased by the downstream rod. The total reduction of pressure loss was obtained 44% by using simultaneously the upstream and downstream rods.