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CHAPTER III RESEARCH METHOD
3.1. Research Place
The research was conducted at Heat Transfer Laboratory of Mechanical Engineering Department of Engineering Faculty of Sebelas Maret University in Surakarta
3.2. Apparatus
a. Model of Vertical Axis Wind Turbine Savonius
Contrive the wind turbine model as following specifications: -
Turbine diameter : 20 cm
- Axis height
: 18 cm -
Overlap of blade : 1 cm
- Number of blade
: 2 blades -
Material of blade : Aluminum
a. Two-blade Savonius Rotor
b. Savonius Rotor with Guide Vane
Figure 3.1 Models of Vertical Axis Wind Turbine Savonius perpustakaan.uns.ac.id
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22 Figure 3.2 Savonius Wind Turbines with Guide Vane Model
c. Guide Vane
This research uses four guide vane designs with the specification of each guide vane as follows:
Figure 3.3 Models of Various Guide Vane Design d.
Wind Source The source of wind for the turbine is fan. The velocity variants were 7.7 ms, 8.6
ms, 9.7 ms, and 10.7 ms. perpustakaan.uns.ac.id
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Tachometer It used to measure rotation speed rpm of the Savonius wind turbine
f. Anemometer
It used to measure wind speed in front of and the turbine.
3.3. Research Procedure
1. Experiment Set-up
- Contrive the model of Savonius wind turbine based on its design
- Prepare and set up the instruments that will be used according to the following
scheme:
Figure 3.4 Experiment set-up 2.
Experiment Steps -
Experiment steps of Savonius wind turbine without guide vane 1
Turn on the fan 1.2 m in front of the Savonius wind turbine at wind velocity of 7.7 ms and wait 3 minutes in order to attain steady wind flow to start taking data
or measurement. 2
Measure the wind speed in front of Savonius wind turbine system from several points using anemometer.
3 Measure the rotation speed rpm on the axis of turbine using tachometer.
4 Repeat the step 2 and 3 for twice, so it would be got three data of wind speeds
and rotation speeds. 5
Make an average of the three data of wind speeds and rotation speed above. The result will be the final data.
6 Repeat the step 1 to 5 for each velocity.
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Experiment steps of Savonius Wind Turbine with guide vane 1
Set-up the guide vane with the basic design to Savonius wind turbine. 2
Turn on the fan at the wind velocity of 7.7 ms and wait for 3 minutes to attain steady wind slow before taking the measurement.
3 Measure the wind speed in front of wind turbine using anemometer. Take the
data of wind speed in some points of wind turbine with guide vane area and average the data from the some spots. The several points were taken at center of
Savonius rotor. Eight points were taken from guide vane system, which were four points at corner of inner height of guide vane, four points at corner of outer
height of guide vane. Two points were about 5 cm away on above and under the Savonius rotor system. The two last points were about 5 cm away on left and
right side of the Savonius rotor system. The result will be the final data. 4
Measure the rotation speed rpm on the axis of wind turbine using tachometer. 5
Repeat the step 1 to 4 for each guide vane designs, which are guide vane with tilt angle of 15°, guide vane with tilt angle of 30° and guide vane with tilt angle of
45°. 6
Repeat the step 1 to 5 for each wind velocity.
3. Data analysis
The data that can be taken after experiments are the wind velocity ms and the rotation speed rpm from the Savonius wind turbine without guide vane and Savonius
wind turbine with variation dimension designs of guide vane. Further, it can be calculate to determine power coefficient C
p
, tip speed ratio λ and torque coefficient Ct. Based
on those calculations, the correlation between wind speeds ms, rotation rpm, tip speed ratio λ, power coefficient Cp and torque coefficient Ct can be clearly drawn on
figure either for Savonius wind turbine without guide vane or the Savonius wind turbine with various designs of guide vane that is presented on the present study.
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3.4. Steps of Research Diagram
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