Showing papers on "Savonius wind turbine published in 2008"

Experimental investigations on single stage, two stage and three stage conventional savonius rotor

Abstract: The performance of single stage (rotor aspect ratio of 1.0), two stage Savonius rotor with rotor aspect ratios of 1.0 and 2.0 (stage aspect ratios of 0.50 and 1.0) and three stage Savonius rotor with rotor aspect ratios of 1.0 and 3.0 (stage aspect ratios of 0.33 and 1.0) are studied at different Reynolds numbers and compared at the same Reynolds number. The results show that the coefficient of power and the coefficient of torque increase with the increase in the Reynolds numbers for all the rotors tested. The coefficient of static torque is independent of the Reynolds number for all the rotors tested. The performance of two stage and three stage rotors remains the same even after increasing the stage aspect ratio and the rotor aspect ratio by a factor of two and three, respectively. For the same rotor aspect ratio of 1.0, by increasing the number of stages (stage aspect ratio decreases), the performance deteriorates in terms Cp and Ct. However, at the same stage aspect ratio of 1.0 and same Reynolds number, two and three stage rotors show the same performance in terms of coefficient of power and coefficient of torque. The variation in coefficient of static torque is lower for a three stage rotor when compared with the variation of coefficient of static torque for two stage or single stage rotor. Copyright © 2008 John Wiley & Sons, Ltd.

A Novel Design of a Savonius Wind Turbine Water Heating in Residential Settings

Abstract: This paper presents a novel wind turbine design to provide heating for hot water storage systems in residential houses. Resulting from market demand, a vertical axis wind rotor (Savonius type wind turbine) was developed. Although this wind turbine's power coefficient (Pc) peaked at 12%, as this design's output is applied to a resistive load, a smart optimising scheme is discussed to hold the Pc at its maximum regardless of wind velocity. Wind tunnel tests confirmed that Pc varies with tip speed ratio (TSR) and that the Pc can be optimised for various wind conditions by switching between differing loads resistances.

Comparative Analysis of a Wind Turbine’s Performances by Means of CFD Simulations

Abstract: It is now possible to virtually assess performances and optimize the new wind turbines designs, due to the computer systems’ increased power and permanently development of the computational fluid analysis (CFD) software. There are various analysis methods, each with benefits and disadvantages. Generally, very accurate results mean a high consumption of computer resources and a significantly long period of calculus. This paper presents the results of the CFD simulation in case of a Savonius wind turbine. Two analyses are made by means of a commercial CFD software: first on a 2D model, and second on a 3D model. Even it is more pretentious from a computing resources point of view, the Shared Stress Transport theoretical model is used as it is more precise. All the results are compared with those from a real model tested in the wind tunnel. Final conclusions take into consideration the simulation time for both analysis and the closeness between the simulated and real results.