Field test for hydraulic turbine discharge and efficiency based on current-meter method

Hydraulic turbine efficiency is one of the important indicators during acceptance inspection. One of the difficulties in field test for hydraulic turbine efficiency is discharge measurement. Current-meter method is widely applied because of its intuition and accuracy. Through test in a Francis turbine with a circular penstock, turbine discharge and efficiency calculation based on current-meter method is discussed in this paper. Test results indicate that integration step-size needs to be small enough to get accurate discharge in graphical integration method. Uncertainty estimation is important and requisite in field test for turbine efficiency, which reflects the actual reliability of test results.