Bend and orifice plate interactions and their influence on the pressure losses in internal flow systems

Abstract

Experimental work has been carried out with a hydraulic flow test rig in which flows of water up to 65 kgs-l can be measured with a weigh-tank and its diverter valve to an accurary of ± 0.2%. The nature of the experimental work has been to investigate the system pressure losses due to the components in line (i) For interference free flow; (ii) For interactions. The components used are 90 degree circular bends and orifice plates. Bends of radius ratios from R/D - 1.49 to 4.89 and nominally standard single-hole and multi-hole orifice plates of area ratios from m – 0.170 to 0.508 have been tested. To investigate the interaction effects arising from an orifice plate in proximity to bends, various bend-orifice plate (in a few instances orifice plate-bend) combinations have been arranged. The bore diameter of duct (or pipe) and bend is approximately D – 145.05 mm and tests have been performed for Reynolds numbers ranging from Re(D) – 0.7 x 105 to 6 x 10(5). In those instances in which results from the experimental work can be compared directly with published results, agreement is good. However, many of the experimental results, particularly the measurements of interactions between bends and orifice plates, are new.