Numerical Study of a Hydrokinetic Turbine

2021 ◽  
pp. 1-21
2021 ◽  
Vol 53 (1) ◽  
pp. 210102
Author(s):  
Ridho Hantoro ◽  
Sarwono Sarwono ◽  
Fernando Parsaulian Panjaitan ◽  
Erna Septyaningrum ◽  
Nuril Hidayati

2019 ◽  
Vol 13 (3) ◽  
pp. 5665-5688
Author(s):  
E. Septyaningrum ◽  
R. Hantoro ◽  
I. K. A. P. Utama ◽  
J. Prananda ◽  
G. Nugroho ◽  
...  

Due to its high energy concentration, hydrokinetic energy from tidal and rivers flow provides great expectation. One of the effective ways to meet the energy production target is to reduce the installation and maintenance effort arranging turbines in such configuration, known as hydrokinetic turbine array. The performance of array configuration is affected by turbine position and rotational direction. This research provides a comprehensive analysis of the effect of turbine rotational direction and position on the array performance. The experimental study and URANS simulation were carried out to gain deeper information. This previous study proposed 3 side-by-side configurations, i.e. Co-rotating” (Co), “counter-rotating-in” (CtI) and “counter-rotating-out” (CtO) and the current study proposed 2 multi-row configurations, i.e. 3T-A and 3T-B. The comprehensive information is provided. Both experimental and numerical study confirmed that the velocity superposition in the interaction zone gives the constructive effect on turbine performance. All site-by-site configurations is able to enhance farm effectiveness. Co configuration is recommended to install in the resource having unpredictable flow direction. However, the CtI is for canal or river since it has better performance. The study for multi-row configuration shows that the downstream turbine has performance decrement due to the bad effect of the upstream turbine wake.


Author(s):  
Cosan Daskiran ◽  
Jacob Riglin ◽  
Alparslan Oztekin

Three-dimensional steady state Computational Fluid Dynamics (CFD) analyses were performed for a pre-designed micro-hydrokinetic turbine to investigate the blockage ratio effect on turbine performance. Simulations were conducted using a physical turbine rotor geometry rather than low fidelity, simplified actuator disk or actuator lines. The two-equation k-ω Shear Stress Transport (SST) turbulence model was employed to predict turbulence in the flow field. The turbine performance at the best efficiency point was studied for blockage ratios of 0.49, 0.70 and 0.98 for three different free stream velocities of 2.0 m/s, 2.25 m/s and 2.5 m/s. Distinct blockage ratio results at a free stream velocity of 2.25 were compared to a previous numerical study incorporating the same rotor geometry within an infinite flowing medium. The pressure gradient between turbine upstream and turbine downstream for blocked channel flows elevated the turbine performance. The increment in blockage ratio from 0.03 to 0.98 enhanced power coefficient from 0.437 to 2.254 and increased power generation from 0.56 kW to 2.86 kW for the present study.


2016 ◽  
Vol 88 (4) ◽  
pp. 2441-2456 ◽  
Author(s):  
PAULO A.S.F. SILVA ◽  
TAYGOARA F. DE OLIVEIRA ◽  
ANTONIO C.P. BRASIL JUNIOR ◽  
JERSON R.P. VAZ

Energy ◽  
2019 ◽  
Vol 174 ◽  
pp. 375-385 ◽  
Author(s):  
Wenhua Xu ◽  
Guodong Xu ◽  
Wenyang Duan ◽  
Zhijie Song ◽  
Jie Lei

2021 ◽  
Vol 9 (8) ◽  
pp. 829
Author(s):  
Minh N. Doan ◽  
Shinnosuke Obi

An open-source 2D Reynolds-averaged Navier–Stokes (RANS) simulation model was presented and applied for a laboratory-scaled cross-flow hydrokinetic turbine and a twin turbine system in counter-rotating configurations. The computational fluid dynamics (CFD) model was compared with previously published experimental results and then used to study the turbine power output and relevant flow fields at four blockage ratios. The dynamic stall effect and related leading edge vortex (LEV) structures were observed, discussed, and correlated with the power output. The results provided insights into the blockage effect from a different perspective: The physics behind the production and maintenance of lift on the turbine blade at different blockage ratios. The model was then applied to counter-rotating configurations of the turbines and similar analyses of the torque production and maintenance were conducted. Depending on the direction of movement of the other turbine, the blade of interest could either produce higher torque or create more energy loss. For both of the scenarios where a blade interacted with the channel wall or another blade, the key behind torque enhancement was forcing the flow through its suction side and manipulating the LEV.


Author(s):  
Oumnia El Fajri ◽  
Joshua Bowman ◽  
Shanti Bhushan ◽  
David Thompson ◽  
Tim O'Doherty

2018 ◽  
Vol 2 (2) ◽  
pp. 70-79
Author(s):  
Anastas Todorov Yangyozov ◽  
Damjanka Stojanova Dimitrova ◽  
Lazar Georgiev Panayotov

A small turbine, working with air and water to generate electricity, was designed and its performance was reported in this paper. The rotor diameter is 150mm. The numerical calculations of the power coefficient, torque, and tip speed ratio of turbine were carried out for a wide range of inlet velocities. The flow passing through the turbine was investigated with commercial CFD code ANSYS CFX 18


Fluids ◽  
2021 ◽  
Vol 6 (5) ◽  
pp. 186
Author(s):  
Santiago Laín ◽  
Leidy T. Contreras ◽  
Omar D. López

This paper presents a numerical study of the effects of the inclination angle of the turbine rotation axis with respect to the main flow direction on the performance of a prototype hydrokinetic turbine of the Garman type. In particular, the torque and force coefficients are evaluated as a function of the turbine angular velocity and axis operation angle regarding the mainstream direction. To accomplish this purpose, transient simulations are performed using a commercial solver (ANSYS-Fluent v. 19). Turbulent features of the flow are modelled by the shear stress transport (SST) transitional turbulence model, and results are compared with those obtained with its basic version (i.e., nontransitional), hereafter called standard. The behaviour of the power and force coefficients for the various considered tip speed ratios are presented. Pressure and skin friction coefficients on the blades are analysed at each computed turbine angular speed by means of contour plots and two-dimensional profiles. Moreover, the pressure and viscous contributions to the torque and forces experienced by the hydrokinetic turbine are examined in detail. It is demonstrated that the reason behind the higher power coefficient predictions of the transitional turbulence model, close to 6% at maximum efficiency, regarding its standard counterpart, is the smaller computed viscous torque contribution in the former. As a result, the power coefficient of the inclined turbine is around 35% versus the 45% obtained for the turbine with its rotation axis parallel to flow direction.


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