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1. Impulse Turbine with Self-pitch Controlled Guide Vanes for Wave Power Conversion: Performance of Mono-vane
Type, International Journal of Offshore Polar Engineering.
2. A Review of Impulse Turbines for Wave Energy Conversion, Renewable Energy Journal.
3. Experimental Investigation on the Dynamic Response of a Moored Wave Energy Device under Regular Sea
Waves, Ocean Engineering Journal.
4. Hydrokinetic Energy Conversion Systems and Assessment of Horizontal and Vertical Axis Turbines for River and
Tidal Applications, Applied Energy Journal.
The turbine can be used for very small head differences and large flow volume
(suitable for river, artificial channel and ocean conditions). The wheel is designed
with eleven blades installed in different arrangements of blades. One important of
this tidal energy converter is environmentally friendly and simple in operating and
maintenance.
Hydrokinetic conversion systems, albeit mostly at its early stage of development,
may appear suitable in harnessing energy from such renewable resources (tides,
wind, etc.). A concept of tidal energy converter (TEC) which is based on shape of
the conventional water wheels, is introduced in this study. Basically, this turbine
has several special features that are potentially more advantageous than the
conventional tidal turbines, such as propeller type tidal turbines. The research
aims to study the potential possibility of eleven-blade turbine using Computational
Fluid Dynamics (CFD) in extracting the hydrokinetic energy of tidal current and
converting it into electricity, and evaluate the performance of the turbine at
different given arrangements of blades which are inclined to the wheel centreline
with angles of 0, 10, 20 and 30 degrees. In all cases of tip-speed ratio (TSR), the
straight blades type (or inclined to the wheel’s centreline with an angle of 0
degree) showed the most effective performance than the others. In the other
words, this type extracts tidal stream energy better than all cases in the study. In
addition, the torque extraction at the rotor shaft of the 0 degree inclined blade type
is the most uniform comparing to the others due to the less interrupted and
fluctuated generation of force for a period of time.
Comparison of performance between different types (especially 0 and 30-degree cases) was done using visualizations of pressure and
force contours on blade surface no. #1 as shown in the picture below. It indicated that the 0-degree type has the highest values of force
distributed on the blade surface at different tip speed ratio (TSR) values.
Abstract
A Numerical Study on Performance of
Water Wheel Type Tidal Turbine M. H. Nguyen, H. C. Jeong, B. G. Kim, J. H. Kim, C. J. Yang
Mokpo National Maritime University, Mokpo City, Republic of Korea
Results
Turbine Design
Conclusions
Meshing Method and Boundary Conditions
References
International Conference on Ocean Energy (ICOE) 2016 – Edinburgh – 23-25 February 2016
High quality mesh strategy is done using ANSYS-Meshing for two calculation
domains: rotor and stationary parts. The dimensionless wall (Y-plus) is ranged
from 1-7 at rotor blades region.
Comparison of force and torque variations extracted in one revolution from the blade No.#1 between 0 and 30-degree types.
Comparison of power efficiency among four kinds of blade arrangement at different TSRs.
1. The 0deg. inclined blade WWT shows the best performance in comparison to
the others, highest discrepancy at TSR 1.2, up to over 10% power coefficient
deviation.
2. WWT works efficiently at TSR range from 0.9 to 1.1, up to 38% power
coefficient at TSR = 1 for 0deg. inclined blade type.
3. When increasing the working angles of the blade inclined to the center of the
rotor, the force of the water flow acting on the blade will be reduced. As a
result, the torque and power extracted will be reduced as well, especially at
TSRs higher than TSR = 1.
4. This kind of turbine has some more advantages than the conventional
turbine, like propeller types, etc. about manufacture, repair and maintain.
00
Hub
300
Blade
Hub
Water
flow
Water
flow
Rotor diameter (m) 1.2
Rotor width (m) 0.5
Blade dimensions (m)
(L x W x T) 0.3 x 0.5 x 0.01
constant for all cases
Number of blades 11
Rated flow speed (m/s) 1 (fixed)
Working angles of blade 00, 100, 200 and 300
Hub
Blades
ω
Water flow
V1
d d
V2
F
ω
Hub
Hub
Side
wall
Inflation
Y-plus
TSR 0.7 0.8 0.9 1 1.05 1.1 1.2
RPM 11.141 12.733 14.324 15.916 16.712 17.508 19.099
Operating Principle
Water flow
Blade No. #1
Water flow
Blade No. #1
Front face Back face Front face Back face
Front face Front face
-200
-150
-100
-50
0
50
100
150
200
250
0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360
Force-TSR 1 - 30deg Torque-TSR 1 - 30deg
Torque-TSR 1 - 0deg Force-TSR 1 - 0deg
Positive value
Negative value
-200
-150
-100
-50
0
50
100
150
200
250
0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360
Force-TSR 1.1 - 30deg Torque-TSR 1.1 - 30deg
Torque-TSR 1.1 - 0deg Force-TSR 1.1 - 0deg
Positive value
Negative value
TSR = 1
Comparison of water flow-turbine interaction at different TSRs for 30-degree type.
TSR = 0.9 TSR = 0.7
TSR = 1.2 TSR = 1.1
0
0,1
0,2
0,3
0,4
0,6 0,7 0,8 0,9 1 1,1 1,2 1,3
TSR
Power Coefficient
30deg inclined type 0deg inclined type
10deg inclined type 20deg inclined type
0
0,1
0,2
0,3
0,4
0,6 0,7 0,8 0,9 1 1,1 1,2 1,3
TSR
Torque Coefficient
30deg inclined type 0deg inclined type
10deg inclined type 20deg inclined type
Rotor blades Conversional
equipment
Channel
Inlet
The study was tested at different TSRs, ranged from 0.7 to 1.2 by fixing inflow
velocity at 1m/s, but changing rotational speed.