Experimental and numerical investigation of flow through gate valve.

Abstract

Flow dynamics within gate valves must be understood in order to address issues such as turbulence, pressure loss, flow separation, and cavitation. This study examines flow behavior within standard and modified gate valves using experimental and computational fluid dynamics (CFD) methods. Water flow within a gate valve, from 25% to full opening, is simulated to analyze velocity, pressure, and turbulence behaviors. With 25% opening, abrupt velocity accelerations in the valve throat initiate extreme pressure losses and intense turbulent flow due to flow separation. These outcomes serve to underscore the need for efficient valve geometries to induce stability in flow as well as suppress energy losses. Comparison between the standard and modified gate valves at 25%, 40%, and 55% openings highlights the advantages of the modified design. The standard valve exhibits high turbulence, high recirculation areas, and high dissipation of energy, particularly at low openings. Conversely, the modified valve cuts down on turbulence, promotes uniform flow, and reduces pressure losses. By removing vortex generation and velocity oscillations, it obtains more stable flow, which increases system efficiency. Further inspection of a 55% open gate valve with different fluids, for instance, water and SAW15W-40 oil, shows the impact of viscosity on fluid flow. Water specifies a smooth velocity profile and low pressure drops, while oil experiences higher resistance, pressure gradients, and shear forces. The new design addresses these differences well, with reduced potential for cavitation and enhanced performance. All these optimizations enhance operating efficiency in applications ranging from oil and gas to water distribution and chemical processing.