Experimental study of the effects of upstream flow condition upon Venturi flow meter performance

The sensitivity of differential pressure flow meters to the condition of upstream approaching flow continues to be a source of concern to both flow meters manufacturers and users. This paper describes the effects of various entrance flow distortions on the performance of a Venturi type flow meter. Entrance flow distortions considered in the present experimental investigation include a uniform flow, a jet like and a wake like distortions. Pressure measurements along the Venturi meter were performed for the fully developed flow condition and the three initial flow distorted conditions. The effect of the inlet flow distortion was studied through the percent shift of the discharge coefficient ΔCd(%) which was found to present a good correlation with the flow Reynolds number. The results indicate that for lower Reynolds numbers, the Venturi meter would perform well despite the drastic distorted approaching flow.