Determining the hydrodynamic indicators of contraction devices

摘要

New formulas are derived for calculating all of the hydrodynamic indicators, specifically, the pres- sure-recovery factor and the coefficient of contraction of a jet of a contraction device(CD)having a known geometry(control devices included)and operating under subcritical turbulent discharge conditions. The use of only a single measured value of the flowrate and the pressure drop in CD as inputs in the calculation formulas simplifies and accelerates hydraulic tests of CDs of all types. A new method for determining the actual incipi- ence of the cavitation in the CD is proposed.