The Research Of Hydrodynamic And Performance Of The Rectangular Turbine

The traditional vertical-axis tidal current turbine whose blades follow circular contrail is one type of energy conversion system extensively tested and studied for tidal current application. Two new type of turbines based on the traditional one are developed, one called rectangle tidal current turbine whose blades follow two parallel lines with the same length front and rear and two semicircular contrail in both sides, the other called diamond tidal current turbine whose blade movement contrail is diamond.First of all, predicting and analyzing the hydrodynamic performance of these two type of turbines based on the existing mathematical models and the computational methods is presented in this paper. One method is also given to calculate the induced velocity, which is the basic principle of turbine hydrodynamics analysis, including single-disk multi -streamtube (SDMT) and double-disk single-streamtube (DDMT) both based on the momentum theory.Then some typical examples and some results drawn by using the introduced methods of the the two type of turbines are given. Much attention is not only focused on the comparison between SDMT model and DDMT model, but also the comparison between rectangle tidal current turbine and diamond tidal current turbine. All of these are the important base of the selecting of turbines, the designing of hydrodynamics performance, and the general designing of tidal current power plant. A pitch angle control strategy for optimizing the hydrodynamic attack angle of the blades of turbines is formulated and some good numerical results are obtained as well.