CFD Prediction and Validation of Butterfly Valve Hydrodynamic Forces

Abstract

This paper presents a computational fluid dynamics (CFD) model developed using the commercial software FLUENT, and presents predicted hydrodynamic force coefficients for a disc-shaped butterfly valve at different valve operating angles. The predicted force coefficients were used to provide estimates of hydrodynamic loads on the butterfly valve during closure against flow. The results of this study expand the knowledge base of butterfly valve hydrodynamic forces. The use of FLUENT for estimating force coefficients was validated by comparing CFD predictions to experimental results for the drag coefficient of a coin-shaped disc placed perpendicular to flow in an infinite flow field. The sensitivity of the results to turbulence model selection, accuracy of discretization schemes, grid quality, and grid dependence was studied as part of the validation. CFD models of the butterfly valve were used to compute drag coefficients, lift coefficients, moment coefficients, and discharge coefficients for the valve at seven different opening positions. The computed discharge coefficients compared very well with experimental discharge coefficients available in the literature, which provided confidence in the accuracy of the predicted force and moment coefficients as well, and suggests that CFD analysis can be a useful tool for predicting drag forces and lift forces on similar hydraulic structures.