Computational analysis of hydrodynamic effects in hydraulic flow turbines (Part 1)

Abstract

Research and elaboration of the systems for conversion of renewable energy sources (RSE) as a research objective present great interest and importance. Hydraulic energy currently is one of the most used, cheap and clean renewable energy sources. A more efficient use of hydraulic energy, in terms of environmental and social impacts, is the conversion of kinetic energy of running river water without dams’ construction. A new design and functional concept of a hydraulic flow turbine with vertical axis and individualized orientation of the hydrodynamic blades was proposed and elaborated. Using a high order panel method the potential flow analysis is performed in order to compute the hydrodynamic lift and moment coefficients. The drag coefficient is computed through a boundary layer analysis. Laminar boundary layer analysis utilizes Falkner-Skan semi-empirical relations. Transition from laminar boundary layer to turbulent boundary layer is predicted through Michael’s criterion. The turbulent boundary layer parameters are computed using the Head’s model and the drag coefficient is provided by Squire-Young formula. In order to maximize the flowing water energy conversion efficiency the blade hydrodynamic profile parameters and blade orientation with respect to flow direction at each position during the turbine rotation are optimized. The total torque, the forces acting on the blades and the performance of 3-, 4- and 5-blades rotor multi-blade hydrodynamic rotor were analyzed.