TY - GEN
T1 - Micro-hydrokinetic turbine operating in the vicinity of a free surface
T2 - ASME 2019 International Mechanical Engineering Congress and Exposition, IMECE 2019
AU - Attiya, Bashar
AU - Altimemy, Muhannad
AU - Daskiran, Cosan
AU - Liu, I. Han
AU - Oztekin, Alparslan
N1 - Funding Information:
This work used the computational resources of the Extreme Science and Engineering Discovery Environment (XSEDE) through the National Science Foundation grant (TG-CTS170051). Specifically, the Bridges system at the Pittsburgh Supercomputing Center (PSC) is used for simulations.
Publisher Copyright:
Copyright © 2019 ASME.
PY - 2019
Y1 - 2019
N2 - Large Eddy Simulation (LES) turbulence and multiphase Volume of Fluid (VOF) model are employed to predict the spatial and temporal characteristics of the turbulent flow structures near micro-hydrokinetic turbine operating in the proximity of a free surface. The turbine power performance and the free surface dynamics, and its interaction with the turbine are characterized by examining the results of both single-phase and multiphase flow simulations. Simulations are conducted at the turbine’s best efficiency point at a tip speed ratio of 1.86 with the rotation rate of 150 rpm and the free stream water velocity of 2.25 m/s. The multiphase flow simulation is carried out at Froude number of 1.06. The results indicate slight interaction between the deformed free surface and the turbine wake structures. Acceleration in the flow velocity is observed near the free surface due to the physical confinement. The results indicate that turbine power generation is reduced by about 2.0%, and the thrust coefficient is reduced by 1.60%. It is demonstrated that the turbine performance at this Froude number is hardly influenced by the presence of the free surface.
AB - Large Eddy Simulation (LES) turbulence and multiphase Volume of Fluid (VOF) model are employed to predict the spatial and temporal characteristics of the turbulent flow structures near micro-hydrokinetic turbine operating in the proximity of a free surface. The turbine power performance and the free surface dynamics, and its interaction with the turbine are characterized by examining the results of both single-phase and multiphase flow simulations. Simulations are conducted at the turbine’s best efficiency point at a tip speed ratio of 1.86 with the rotation rate of 150 rpm and the free stream water velocity of 2.25 m/s. The multiphase flow simulation is carried out at Froude number of 1.06. The results indicate slight interaction between the deformed free surface and the turbine wake structures. Acceleration in the flow velocity is observed near the free surface due to the physical confinement. The results indicate that turbine power generation is reduced by about 2.0%, and the thrust coefficient is reduced by 1.60%. It is demonstrated that the turbine performance at this Froude number is hardly influenced by the presence of the free surface.
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U2 - 10.1115/IMECE2019-10899
DO - 10.1115/IMECE2019-10899
M3 - Conference contribution
AN - SCOPUS:85078765048
T3 - ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE)
BT - Fluids Engineering
PB - American Society of Mechanical Engineers (ASME)
Y2 - 11 November 2019 through 14 November 2019
ER -