Savonius Wind Turbine New Design

Presented by:�Abdelrahman Elkaffas�Mohamed Rabeh�Christopher Fayez�Mohamed Ahmed

Supervised by:

Prof. ElSayed Saber

Prof. Adel Tawfik

INRODUCTION & SURVEY

Renewable Energy�

• Definition:

An alternative to fossil

fuels

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• Advantages:

Unlimited, non-polluting

And cheaper

History Of Renewable Energy

• Waterwheels in 200 BC
• Solar panels in 1860
• Wind turbines in 1927
• Zaafarana wind farm

In 2019

Fossil energy Vs. Renewable Energy

Types Of Renewable Energy�

• Solar Energy

• Hydro-Energy

Types Of Renewable Energy�

• Tidal Energy

• Geothermal Energy

Types Of Renewable Energy�

• Biomass Energy

• Wind Energy

Wind Turbines

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• Definition:

Devices used to harness Wind energy

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Types Of Wind Turbines

• HAWT

• VAWT

Horizontal Axis Wind Turbines

• Design:

Like that of an

air-plane wing

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• Working principle:

Pressure difference

Creates lift

Installation & Number Of Blades

• Upwind

• Downwind

Wind Turbines

• Components

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Vertical Axis Wind Turbines

• Design:

All designs has

a vertical axis

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• Applications:

Houses, storage units

Vertical Axis Wind Turbines

• Types:

Savonius, Helix & Darrieus

Darrieus Wind Turbine

• Design :

Looks like an egg-beater

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• Working Principle:

Creates lift to move

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• Advantages:

Easy sit-up

Always facing the wind

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Helical Wind Turbine

• Design:

Look like giant DNA helixes

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• Working Principle:

Creates lift & drag to rotate

• Advantage:

The are gearless

Increased Output

Savonius Wind Turbine

• Design:

Looks like the letter S

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• Working Principle:

Relies mainly on drag

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• Advantages:

Hard conditions capabilities, compact

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Icewind Design

• Formed in 2012

By Sæþór Ásgeirsson

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• A modified on Savonius

turbines

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• Hard weather conditions

capabilities

Icewind Design cont.

• Features added to the design

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• Efficiency Increased

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• A wide range of applications

VAWT vs. HAWT

VAWT vs. HAWT Cont.

LITURATURE SURVEY

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• A lot of researches worked on improving the performance of the Savonius turbine by improving the torque and power coefficients

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LITURATURE SURVEY

• Curtain Arrangement
• End Plates
• New Blade Profile
• Adding Fins
• Guide Box
• Number of Blades
• Number of Stages

THEORETICAL MODELING

Theoretical Modeling

• The aim of this part is to derive an equation for Torque with the angle of attack (a) to understand how (a) affects the torque.

Aerodynamics

Mechanics

• 𝑇 = 𝐽 ∝ [4]

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• J=nJ_b + J_s + J_d [5]

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• 𝐽 = ∫_mass 𝑟²𝑑𝑚 [6]

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Mechanics

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• 𝑟 = 𝑑 𝑐𝑜𝑠 ∅
• 𝑑𝑚 = 𝜌𝐻𝑡(𝑑 𝑐𝑜𝑠 ∅)𝑑∅

Mechanics

Mechanics

• T = force * distance

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Mechanics

Mechanics

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Mechanics

Using MatLap To Plot The Relation

• clear, clc
• R=0.1;
• H=0.2;
• p=1.12;
• v=[2.67 , 4.39 , 6.1127 , 7.81281 , 9.51284 , 11.2129 , 12.9129];
• Cd2=[1.4572 , 2.0132 , 2.266 , 2.483 , 1.4965 , 1.904 , 1.4934];
• Cd1=[0 , 1.2401 , 1.0092 , 0.9209 , 1.3418 , 1.3608 , 1.4041];
• alpha=[0 , 30 , 60 , 90 , 120 , 150 , 180];
• T=(1./2).*p.*(R.^2).*H.*(v.^2).*((sin(alpha)).^2).*(Cd2-Cd1)
• plot(alpha,T);
• xlabel('Angle of Attack \alpha') , ylabel('Torque (Nm)');
• title('The Effect of \alpha on Torque')

Relation Between T & a

Projected Area

Projected Area For a=0

Projected Area For a=180

Projected Area For a= 90 ͦ

EXPERIMENTAL STUDY

Experimental Study

• The experimental study will be carried out in two main experiments.
• Experiment 1: study the bearing friction force & drag coefficient.
• Experiment 2: measure the static torque for different angular position at various wind speeds.

Experimental Setup

Experimental Setup

Experimental Setup

Blades Design & Manufacturing

Shaft Design

• Shaft was made of three parts:
• Aluminum rod (D=25 mm)
• Artylon (acts as coupling between the two shafts)
• Steel pipe (Do=17 mm & Di=16 mm)

Data Reduction

Experiment 1

• Turbine rotor position in the downstream side of the wind tunnel exit section.
• Extending the turbine distance for the same wind speed to get a flow diagram of wind flow distribution.
• Repeating the experiment for different speeds.

Experiment 2: Bearing friction and aerodynamic effect

1. Disconnect the resisting mechanism at the end of the rotor assembly.
2. Start the wind tunnel with controlling the speed of the fan.
3. Adjust the speed of fan and measure the wind speed.
4. Measure the rotor speed at no load till reaching the steady state condition using the speed sensor attached to the rotor.

Experiment 2: Bearing friction and aerodynamic effect

5. Stop the stream of the turbine rotor by cutting the air flow using a power barrier.
6. Record the variation of the rotor speed with time and estimate the free braking time to
7. Repeat the steps 4-6 at different operating wind speeds.

Experiment 3: Static torque produced by Savonius rotor for different angular position at various wind speed

1. Adjust the rotor blades to be at the specified position 0,30,60,90,120,150 and 180.
2. Rotate the worm to increase the forces F1 and F2and then loading the rotor of the turbine , loading the break drum measuring system until the force f4 reach a value about 5 Kg.

Experiment 3

3. Start the wind tunnel and adjust the speed of the fan to obtain the required value of the air velocity at downstream from the wind tunnel exit section.
4. Use the pitot static tube which attached to the inclined manometer to measure the velocity of the free air stream up stream of the rotor position.
5. Make a fine turning for the fan speed to get the desired value of the free air velocity.

Experiment 3

6. Release the loading of the brake down system by ready the worm gradually in the c.c.w direction till the rotor start to move.
7. Make a fine turning for the motion of the worm to obtain the condition for static torque.
8. Record the value of F1 and F2.
9. Determine the value of static torque.
10. Calculate the static torque coefficient Cts.

Experiment 4: The torque coefficient and the power coefficient of the power rotor

1. Put the rotor at the desired position.
2. Put the pitot static probe upstream of the rotor about 10 cm to measure the velocity of the force stream of the air.
3. Start the wind tunnel and adjust the speed of the fan to obtain the required air velocity, measure the air velocity using pitot static probe.

Experiment 4

4. Adjust speed of the rotor by changing the resisting moment actin on the rotor by changing the forces F1 and F2 through the rotation of the worm.
5. Measure the values of rotor speed in RPM, F1 & F2.
6. Calculate the value of the torque T.
7. Calculate the tip speed ratio TSR.
8. Calculate the coefficient of torque Ct.
9. Repeat steps from 4 to 9 by changing rotor speed.

RESULTS & DICUSSION

Results

Results

Discussion

• The modified rotor provides higher torque at lower rpm than the traditional rotor.

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• The setup equipment provides an advantage of make many experiments in a compact unit.

Discussion

• At 2500 rpm torque is higher in modified Savonius wind turbine, but when the rpm reaches 3000 rpm centrifugal forces becomes higher than air pressure force that pushes the gates and the turbine acts as a traditional Savonius wind turbine.

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Conclusion

• A recommendation for this problem is to make the gates of a material that is lighter than aluminum or make the gate closer the shaft also to reduce the centrifugal force.
• Another recommendation is make the shaft lighter for smoother operation.

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THANK YOU

References

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