Numerical Simulation of the Flow Field to the Double Eccentric Butterfly Valve and Performance Prediction

The butterfly valve performance such as the curves of discharge coefficient is essential for predicting the ability of the valve to operate it along with other essential coefficients necessary for making sure the suitable operation. The availability of performance coefficients for incompressible flow is limited, and experimental testing can be cost prohibitive. However, the extrinsic ability of regulate on the valve mostly rely on the inherent structure of flow field and the law of changing. The capability of using computational fluid dynamics is tested to determine its viability for determining performance coefficients. The flow fields, curves of discharge coefficient, cavitations and pressure recovery factor of a symmetric double eccentric disk butterfly valve are studied under different opening angle in detail. The flow fields are predicted by using the semi-implicit method for pressure-linked equation SIMPLEC and the k-epsilon turbulence model based on the theory of isotropic eddy viscosity. The computational predictions for each factor were compared to test data and the numerical results were generally in good agreement with test data, although a few disparities existed.