Unsteady Flow Phenomena of Wells Turbine in Deep Stall Condition

摘要

In order to make clear the hysteresis behavior of Wells turbinernperformance including deep stall condition, experimental and numericalrninvestigations were made for the hysteretic characteristics includingrndeep stall condition of Wells Turbine. The experimental investigationrnwas made by the use of the turbine equipment in which a sinusoidalrnflow condition was simulated. The numerical investigation was madernby an unsteady three-dimensional Navier-Stokes numerical simulation.rnThe experimental and calculated turbine unsteady performance showrncharacteristic two hysteretic loops. The counterclockwise hysteresisrnloop in unstalled condition can be associated with the separation on thernsuction surface near the hub, whereas the clockwise hysteresis loop inrnstalled condition can be associated with the separation on the suctionrnsurface near the tip