Cristian Cardona-Mancilla ¹, Jorge Sierra-Del Rio ¹, Diego Hincapie-Zuluaga ¹

Affiliations
1 Instituto Tecnologico Metropolitano. Medellin, CO

Abstract

Objectives: To increase the hydrodynamic efficiency of horizontal axis hydrokinetic turbines from the implementation of various geometric configurations of diffusers. Methods/Statistical Analysis: The turbine has a radius of 0.75 m and it’s made up of three blades, they were designed using the hydrodynamic profile NREL S822. On the turbine a second and third generation diffuser are also implemented. The simulation was developed in the ANSYS CFX18.2 program in transitory regime, using a turbulence model k-ε, a water input speed of 1.5 m s^-1 and a variation of the angular velocity from 0 to 160 RPM. Include the method adapted to study the objectives/sampling details or simulation or statistical analysis of data; technique employed; mention unique/important points of modification of methodology in the current study. Mention about test samples the control employed or approach used for comparing the test sample. Findings: As a result, the power coefficient (C_p) of the three generations of the hydrokinetic turbine was obtained, in addition to the velocity profile of each model. Increase in velocities both upstream and downstream of the turbine were found for the third-generation turbine, presenting values of 1.5 to 2.1 m s^-1 and 2.3 to 2.6 m s^-1, respectively. The maximum power coefficient (C_p,max) reached by the first, second and third generation turbine was 0.285 at a TSR of 100, 0.296 at a TSR of 90 and 0.487 at a TSR of 95, respectively. This is equivalent to an increase of 41.5% and 39.2% of the C_p of the third-generation model with respect to the first and second-generation turbine, respectively and of 82.1% in relation to the Betz limit. Mention your findings in the form of statements along with the conclusive data of statistical importance; Mention how your findings are unique and novel; how your findings are in consensus with the existing values/reports or how different are they from the already reported findings. Highlight how your results are helpful in adding more value to the existing reports. Application/Improvements: The implementation of this type of turbines is aimed at the generation of electric power, promoting in greater measure the distributed generation in isolated areas near water sources.

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