Compressible Flow through a Butterfly Throttle Valve in a Pipe

This work is put in perspective by mentioning some of the applications of butterfly throttle valves and explaining how the next tests are complementary to other work (1). The present tests examine the flow characteristics of a butterfly throttle valve in relation to valve opening, pressure ratio and circumferential and axial location of the pressure tappings.

The paper gives results of a comprehensive series of steady flow tests and, also, results of a limited number of unsteady flow tests. In the latter, the butterfly throttle valve was located in the intake system of a single cylinder diesel engine.

The paper highlights the importance of the position of pressure tappings when pressure measurements are used to estimate flow rates. The results of the present study show that when suitable precautions are taken the quasi-steady flow method may be used to predict the flow rates under pulsating conditions.