Eventos Anais de eventos
COBEM 2021
26th International Congress of Mechanical Engineering
CFD analysis of pressure variations on the waste valve of a hydraulic ram pump
Submission Author:
Henrique Priebe , RS , Brazil
Co-Authors:
Gustavo Faturi, Henrique Priebe, Luciano Lasch dos Santos, Pedro Bottlender, Vinícius Roso
Presenter: Pedro Bottlender
doi://10.26678/ABCM.COBEM2021.COB2021-1744
Abstract
Hydraulic ram pumps where invented around 1775 and arouses interest due to one of its main characteristics: to elevate a fluid to considerable heights using its own kinetic energy without using a power source external. This is due to the abrupt closing of the waste valve during the fluid flow, causing the phenomenon known as water hammer, which induces the opening of the discharge valve, leading the fluid to the accumulator and then raising it. Currently, computer simulation of fluid dynamics carried out studies and experiments in various components, helping to increase efficiency and consequently the field of applications of this equipment. However, no much research has been done on the waste valve, one of the main components of the hydraulic ram pump and responsible for the phenomenon on which its operation principle is based. Then, this study aims to determine the waste valve influence on the total efficiency of a hydraulic ram pump and thus, propose design changes to improve pump performance. For this, computational fluid dynamics (CFD) analyzes were performed using Ansys Fluent software through the pump body. The pump geometry chosen was based on a real hydraulic ram and the discharge valve is considered closed in order to simplify the simulation. It is already known that the pressure on the bottom surface of the waste valve interferes with its closing speed, with higher pressures resulting in higher speeds and increased pump efficiencies. To increase this pressure, simulations were performed with the valve originally plane, changing its geometry to the concave shape, also varying the inlet pressure for both geometries and considering two cases of height difference. The simulations resulted in a higher pressure on the surface of the plane valve for the lowest inlet pressure and, on the other hand, in a greater pressure on the surface of the concave valve for the highest inlet pressure, thus showing that the proposed change in geometry would result in positive effects for greater fall heights.
Keywords
Waste valve geometry, Inlet pressure, performance
