Power Outputs of Two Stages of Cross‐Flow Turbine

Abstract

This study attempts to identify the contribution of the two stages of power generation to the shaft power in a cross‐flow turbine. A special model of the turbine is built to allow insertion of a flow diverter inside the runner. A flow diverter is also designed to intercept the flow that passes through the first stage of the turbine. Tests are conducted with and without the diverter to determine the contribution of the two stages of the turbine to shaft output. Measurements are taken to ensure that presence of the flow diverter does not cause back pressure inside the nozzle. Contribution of the first stage to output is determined from tests with the diverter installed. Total shaft power is determined by removing the diverter. The balance between the two is the contribution of the second stage. The turbine's second stage contributes more significantly to the shaft output than reported in the analytic literature. Turbine efficiency can be improved if efforts are concentrated on improving the performance of the turbine's second stage.