Hysteretic characteristics of biplane wells turbine in a deep stall condition

Abstract

In order to make clear the hysteresis behavior of biplane Wells turbine performance in deep stall condition, numerical investigations were made for the hysteretic characteristics in deep stall condition of biplane Wells Turbine. The numerical investigation was made by an unsteady three-dimensional Navier-Stokes numerical simulation. The calculated turbine unsteady performance show two characteristic loops. A counterclockwise hysteresis loop is observed in the unstalled condition and a clockwise hysteresis loop is observed in the deep stall condition. By dividing the torque and total pressure drop coefficient values between the one for upstream blade and the one for downstream one, it is found that the clockwise hysteresis loop can be seen only for the downstream blade. Copyright © 2005 by The International Society of Offshore and Polar Engineers.