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Influence of the diffusor angle and a damper opening angle on the performance of a hydrokinetic turbine
Author(s) -
Chica E.,
Pérez F.,
RubioClemente A.
Publication year - 2018
Publication title -
environmental progress and sustainable energy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.495
H-Index - 66
eISSN - 1944-7450
pISSN - 1944-7442
DOI - 10.1002/ep.12706
Subject(s) - turbine , diffuser (optics) , damper , computational fluid dynamics , airfoil , marine engineering , mechanics , power (physics) , angle of attack , tip speed ratio , flow (mathematics) , materials science , structural engineering , environmental science , engineering , aerodynamics , mechanical engineering , physics , optics , thermodynamics , light source
Computational fluid dynamic (CFD) technique has been used to investigate the effect of the diffuser expansion angle on the power coefficient of a hydrokinetic turbine. The performance coefficient was compared to that of a conventional bare hydrokinetic turbine of 1 Hp (746 W) designed for a water velocity of 1.5 m s −1 with a tip speed ratio of 6.325; an attack and pitch angle of 5 and 0 degrees, respectively; a power coefficient of 0.4382; a drive train efficiency of 70% and a S822 airfoil profile. The CFD results showed that the extracted power of the hydrokinetic turbine with diffuser can be larger than the power extracted by a bare turbine with the same area. Nevertheless, the level of stress on the blade structure was also increased due to the hydrokinetic turbine with diffuser was exposed to a larger structural loading condition by the water flow. Additionally, the numerical analysis of a damper located at the exit of the turbine diffuser was developed. It was observed that when the opening angle of the damper is between 0 and 20 degrees, an increase in the mass flow through the turbine blades is achieved, resulting in a slight increase in the power coefficient. © 2017 American Institute of Chemical Engineers Environ Prog, 37: 824–831, 2018