Study on Gibson Method of Flow Measuring : Infiuence of Coefficient of Pipe Friction Losses

Abstract

Recently, the Gibson method has been used for flow measuring at hydraulic power plants, but the obtained results have never been compared with volume or weight measurements. Therefore the accuracy of the method is uncertain. Authors made comparative experiments between the weight measurements and the Gibson method by means of a test apparatus of 3 in. diameter pipe line. As a result of the tests, the relative errors of the Gibson method were found to be positive for rapid gate closure, and negative for slow gate closure. The variations of discharge did not affect the discrepancies. The authors proposed such a new treatment of fluid friction coefficient in the Gibson method analysis that the relative errors might become smaller particularly for slow gate closure.