Author(s)

J.-M. Gagnon & C. Deschênes

Abstract

We have seen many papers in the past few years reporting research on Francis hydraulic turbine flow. Interesting papers assessing the accuracy of the CFD numerical simulation were also presented for axial turbine draft tubes, as in the three Turbine 99 workshops. However, little knowledge is available on the flow taking place inside an axial turbine. This paper focuses on the unsteady rotor-stator interaction in a propeller axial turbine. The flow behaviour is analysed at different rotor and stator relative locations with numerical simulations using a commercial code and k- ε turbulence model. The main goal is to study unsteady flow phenomena such as wake, separation, forces and pressure fluctuations in the propeller turbine. This investigation will help to design a series of flow measurements used in turn to improve future CFD simulations with realistic velocity profiles as boundary conditions. Keywords: propeller turbine, numerical simulation, blade torque, partial load. 1 Introduction Low head power plants are expected to be implemented increasingly in the future for economical, geographical and environmental purposes. Propeller turbines are well suited for these types of applications. They operate at higher flow rate, smaller head and faster rotational speed, thus being more compact than other types of machines. The US Department of Energy (DOE) is anticipating major growth for low head power plants [1] and studies such as Turbine 99 [2] or the work of Roussopoulos and Muntean [3, 4] show research trends on axial hydraulic machine. On a global perspective, optimization of size and weight

Keywords

propeller turbine, numerical simulation, blade torque, partial load.