Analysis of Hydraulic Loss Characteristics of Francis Turbine Based on Entropy Production Theory
To investigate the internal complex flow and induced hydraulic loss characteristics of hydraulic turbine un-der no-load conditions,the Reynolds time-average method was used to numerically simulate the no-load and nearby work-ing conditions of a large Francis turbine at the rated head.The different types of hydraulic losses of the core flow passage components were quantitatively analyzed based on the entropy production theory.By defining the streamline coordinate system,the distribution of internal losses in the runner was quantitatively studied,and the distribution characteristics and causes of hydraulic losses under no-load conditions were clarified.The results show that the hydraulic loss of the movable guide vanes,runner and draft tube is dominant,and the large-scale eddy structure in the bladeless zone,the reflux phe-nomenon of the pressure surface of the runner and the high flow velocity vortex of the straight cone section of the draft tube are the main reasons for the increase of indirect dissipation.
hydraulic turbinenumerical simulationentropy production theoryno-load conditionhydraulic loss
万方数据
维普
