STUDY ISOVELOCITY FIELD TO VALUATION OF THE POSITIONING OF HYDROKINETIC

In open channels the water flow can be described through a mapping of longitudinal velocity or isovelocity fields (isovel), it described in the transverse section. The Maximum velocity region in the river cross section could be identifying when the interest is hydrokinetic energy generation in rivers. The purpose of this study is to analyze the maximum velocities variation in the transverse section of Maracá River, near by a sustainable development protection region. O objective is to estimate the potential hydrokinetic energy generation. The quantification methodology of isovel and seasonal flow was based in hydrometric techniques using propeller reel along vertical profile. The experimental measurements were performed twice: the first in October 2007 (minimum flow) and seconde in February 2008 (near maximum flow). In the analyzed period was observed a significant variation in the geometric positioning isovel, which occurred probably due to change in the flow characteristics and of influence on geometry of wet perimeter over the flow. The variation of the position of maximum isovel was significant, indicating need for lateral repositioning of the turbine axis hydrokinetic for each season. This study has observed that the seasonally variation could be considerate a relevant parameter in projects of structures of support of turbine axis, improving the turbine operational efficiency and the electric generation capacity. This proceeding could be carried out by a simple adjust in the lateral positioning in the machine axis indicates for the biggest isovel.