An Investigation of Compressible Flow Characteristics of Butterfly Valves

Abstract

Compressible flow characteristics including mass flowrate, onset of “choked” flow, stagnation pressure loss, and static pressure recovery have been investigated for butterfly valves. A simplified sudden-enlargement in flow area theoretical model has been used to characterize the overall mass flowrate and pressure characteristics of the valve flow. A series of small-scale compressible flow experiments has also been conducted using sudden-enlargement configurations with different nozzle geometries and using geometrically similar model valves. These experiments provided a database for augmenting the simplified theoretical model with needed empirical information and for assessing the range of applicability of the theoretical model. This method can be used to predict the mass flow and pressure characteristics of full-scale valves based on model experiments and/or to determine the overall operating characteristics of full-scale valves from in situ pressure measurements.