478
V. Kaushik and R. N. Shankar
Table 2 (continued)
Authors
Wind tunnel
dimension
(m × m)
Test section
type
Dimension of
rotor of VAWT
(H × D) (m ×
m)
Maximum C p TSR
Three stage
0.225 × 0.225
0.96 × 0.289
Three stage
13.2
0.77
Sheldahl [30]
4.6 × 6.1
Open type 2 × 0.98
0.32
4.70
Gupta et al. [4]
0.3 × 0.3
Open ckt
1.2 × 0.08
0.3579
0.4950
Scungio et al. [13] 0.3 × 0.3
Closed ckt 0.15 × 0.2
0.161
1.24
Meana-Fernandez
et al. [31]
4.45 × 2.80
Closed loop
open jet
0.4 × 0.6
0.45
3.5
Wenehenubun et al.
[23]
–
Open
circuit
0.37 × 0.37
0.35
0.555
(2) Many field tests that have carried out by the researchers have been included
in this paper to understand about the three-dimensional characteristics and
performance under natural wind conditions.
(3) The aerodynamic design of the rotor has also evaluated by the wind tunnel
experimentation to measure various parameters like tip speed ratio, power coefficients, torque coefficient, blockage effects, overlapping effects, effect of Re
number, and effect of blade number on the performance of the rotors.
5 Future Scopes for Research
1. Development of the methods to evaluate the innovative configurations of VAWT
which comprises of variable pitch blades and tip devices for the rotor which can
automatically adjust itself as per the flow field, so as to enhance the aerodynamic
performance.
2. Many researches have to be carried out on various configurations which include
the confined or closed VAWT structure which is having a nozzle-like structure
at the opening end of the rotor from where the air is directed toward the blades
of the turbine.
3. Development of the techniques for the flow visualization and to determine the
flow separation points during turbulent flow and methods to avoid the flow
separation.
V. Kaushik and R. N. Shankar
Table 2 (continued)
Authors
Wind tunnel
dimension
(m × m)
Test section
type
Dimension of
rotor of VAWT
(H × D) (m ×
m)
Maximum C p TSR
Three stage
0.225 × 0.225
0.96 × 0.289
Three stage
13.2
0.77
Sheldahl [30]
4.6 × 6.1
Open type 2 × 0.98
0.32
4.70
Gupta et al. [4]
0.3 × 0.3
Open ckt
1.2 × 0.08
0.3579
0.4950
Scungio et al. [13] 0.3 × 0.3
Closed ckt 0.15 × 0.2
0.161
1.24
Meana-Fernandez
et al. [31]
4.45 × 2.80
Closed loop
open jet
0.4 × 0.6
0.45
3.5
Wenehenubun et al.
[23]
–
Open
circuit
0.37 × 0.37
0.35
0.555
(2) Many field tests that have carried out by the researchers have been included
in this paper to understand about the three-dimensional characteristics and
performance under natural wind conditions.
(3) The aerodynamic design of the rotor has also evaluated by the wind tunnel
experimentation to measure various parameters like tip speed ratio, power coefficients, torque coefficient, blockage effects, overlapping effects, effect of Re
number, and effect of blade number on the performance of the rotors.
5 Future Scopes for Research
1. Development of the methods to evaluate the innovative configurations of VAWT
which comprises of variable pitch blades and tip devices for the rotor which can
automatically adjust itself as per the flow field, so as to enhance the aerodynamic
performance.
2. Many researches have to be carried out on various configurations which include
the confined or closed VAWT structure which is having a nozzle-like structure
at the opening end of the rotor from where the air is directed toward the blades
of the turbine.
3. Development of the techniques for the flow visualization and to determine the
flow separation points during turbulent flow and methods to avoid the flow
separation.