8 ’ 80 B Journal of Applied Sciences 4 (1): 144-148, 2004 ISSN 1607-8926 © 2004 Asian Network for Scientific Information Corresponding Author: Dr. Ali Vardar, Department of Agricultural Machinery, Faculty of Agriculture, Trakya University, 59030 Tekirdag, Turkey, Tel: +902822931442 (192) E-mail: avardar@tu.tzf.edu.tr 144 An Experiment on the Electric Energy Performance of the Wind Turbine Rotors Ali Vardar and Bülent Eker Department of Agricultural Machinery, Faculty of Agriculture, Trakya University, 59030 Tekirdag, Turkey Abstract: First of all 270 sets of miniature wind turbine rotors with different properties were produced by using some NACA profiles. The produced 270 sets of rotors of different forms were tested in a wind tunnel. During the test, the electric voltages and the electric currents that each rotor form generated under different wind speeds were measured. Then the performance of each rotor form was laid down in view of such measurements. The rotor form made of NACA 4412 profile, with two blades, which are coupled to the rotor with a twisting angle of 0° and a blade angle of 5° was defined as the rotor form yielding the highest performance. The energy which was generated by this rotor form was 161,73 mW. Key words: Wind turbine, rotor blade, electric energy performance INTRODUCTION Nomenclature Energy is the most important power on the earth. But B : number of blades the electric energy that is produced on the earth causes C : tip chord width (m) environmental problems of which reason lies at its source. D : rotor diameter (m) Nowadays has come to use such energy sources, which A : rotor cross section area (m ) are clean and sustainable. d : rotor diameter (m) While investigating solutions for the energy problem, N : electric energy generated by electro motor (mW) some sectors should also consider the alternative to U : electric voltage produced by electro motor (V) demand less energy from the national energy network by I : electric current produced by electro motor (mA) producing their own energy, rather than producing more. In view of this, small and medium size operations could MATERIALS AND METHODS produce their own energy in order to meet their energy requirement. Blades: The blades that were used during the tests are Clean and sustainable energy sources by which small made of “Balsam” (Fig. 1) tree with a considerably low and medium size operations could produce their own strength and with a density of 0.075 g cmG . The blades energy are miscellaneous. One of those energy sources is are designed with a rotor diameter of 310 mm and a hub the Wind Energy. diameter of 48 mm (the component at the centre of the The installation cost of giant wind turbines that are rotor that conveys to the blades the wind incoming to the intended and designed to generate electric energy is very rotor centre) and a blade length of 130 mm (Fig. 2). high therefore small and medium size operations could The guidelines that are recommended by NACA were hardly afford it. For this reason, high-performance wind considered in selecting blade profiles . turbines that could be afforded by small and medium size The number of blades of the blade profiles used operations must be developed . during tests as well as their tip speed ratios could be [1] Attaining a high performance from a wind turbine computed by the following equation (3): depends on a variety of factors. Among such factors are the height of the wind turbine and the rotor area. Still (1) another one is the blade structure. The factors as the turbine height and the rotor area shall require a larger turbine size. This in turn will directly influence the cost. When the number of blades used during test is taken But optimisation of the blade structure shall not require two, three and four in the above equation, the tip speed any increase in size and thus its cost will be low. ratios shall be as follows: 8 : tip speed ratio 2 3 [1] [2]