In the present paper the new wind tunnel located in the Fluid-dynamic Laboratory of the Dipartimento di Ingegneria Meccanica e Gestionale (DIMeG) of the Bari Polytechnic will be shortly described and the first experimental measurements on a vertical axis wind turbine (VAWT) will be shown. The DIMeG wind tunnel has been designed by the research group on wind energy of the Department. It is a subsonic, closed loop, wind tunnel with a transparent test part where small scale models can be analyzed. A four bladed axial fan is driven by an asynchronous three phase electric motor, which is connected to an inverter in order to change the wind speed. Angular blades have been inserted at the two curves between the fan and the test section in order to increase the uniformity of the velocity profile after the two curves. An optimization fluid-dynamic study has been carried out in order to find the best blade profile. A honeycomb has been also inserted upstream the test section in order to destroy the still existing small vorticity generated by the fan and the curves. A three-axis traversing, called Cartesian robot, has been designed and built above the test section, in order to move the hot wire probe, for wind speed measurements, by means of four step by step electric motors controlled by a personal computer. A data acquisition system has been set up. All the principal commands and controls can be performed by a dedicated personal computer, which has been programmed using LabVIEW® G-programming language. The first experimental activity has been performed on a VAWT model, of the Giromill type with parallel blades. The turbine has been connected to an AC brushless servo, able to control the braking torque. Experimental results of the flow field in two horizontal planes have been set up using a two component hot wire probe (Dantec 55R51) calibrated with the manual system Dantec 54H10. The measurement grid adopted is formed by 20 nodes in the Y direction (main flow direction) and 10 nodes in the X direction.
|Titolo:||Experimental results of a vertical axis wind turbine|
|Data di pubblicazione:||2010|
|Nome del convegno:||ASME 2010 10th Biennial Conference on Engineering Systems Design and Analysis, ESDA 2010|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1115/ESDA2010-25251|
|Appare nelle tipologie:||4.1 Contributo in Atti di convegno|