Design of a Windmill for the Water Pumping in a Sprinkle Irrigation System

Abstract

Introduction: The use of the wind energy with practical ends is referred from old times; however at the present time it recovers validity for the necessity of finding alternative sources of energy in front of the conventional fossil fuel that is more and more scarce and it causes serious problems of environmental contamination.   Objective: Design a windmill for the extraction of water in a simple and efficient way, from the principles of a multiblades windmill and the use of materials recovered in the locality that allows the irrigation of the garlic cultivation with sprinkle irrigation system at the minimum possible cost.   Methodology: Different methodologies like the experience of the producers, established technical approaches for the selection of the relationship of speeds diameter of the rotor, coefficient of sustentation; haulage coefficient and attack angle were used. The analytic method was used for the calculation of the coefficient of solidity, the cord angles, the coefficient of power, the useful power, real flow, hydraulic power of the pump, total force in the piston, centrifugal force, sustentation force, drag force and the starting torque generated in a windmill.  Results: They were obtained starting from the wind speeds registered in the locality during 30 years of systematic studies and the defined parameters and calculated for the wind rotor and the volumetric pump.  It was possible to design a windmill with the mechanical and hydraulics characteristics appropriate to be used in the agriculture.  Conclusions: The investigation demonstrated that the design of the windmill allows to complete the demands of the pumping of water for the irrigation system when guaranteeing a real flow of 0,17 L s-1 and a volume of water of 0,30 L displaced by the pump in each revolution of the wind rotor. The power generated by the wind rotor satisfies the power required by the pump.