Effect of Air Vessel Configuration on Transient Pressure

Abstract

Hydropneumatic tanks can effectively safeguard pressurized systems from the risk of water hammer. This paper examines the in uence of both air vessel aspect ratio (R = height/diameter) and its form; cylindrical (vertical and horizontal) and spherical, on the transient pressures resulting from the abnormal working events of pumps. Bentley HAMMER software, which uses the Method of Characteristics to solve the momentum and continuity equations for unsteady ow, was foremost veri ed and then utilized in the analysis. Three case studies were considered. The results show that, for the same operating conditions, R has an insigni cant effect on the maximum and minimum pressures, and as R increases, the extreme pressures improve slightly. Furthermore, the hydraulic performance of horizontal cylindrical, vertical cylindrical, and spherical air vessels, under transient conditions and at the same volume, is identical and the small differences in the transient results could be attributed to the change in pressure of air/gas inside the vessel that results from the variance in the vessel's cross-sectional area.