1. PRESENTATION BY:- DARSHAK.M.K
UNDERWATER WINDMILL
PRESENTATION BY:-
DARSHAK.M.K

2. DEFINITION
An Underwater windmill is a device which gets power from the tides. The gravitational pull of the moon produces a swift tidal current, which courses through the channel and spins the long blades of the turbine.

3. PRINCIPLE:
It works on the principle, much like windmills, but driven by flowing water rather than air.
Normally in a windmill the generators are connected to battery charging circuits and finally to large utility grids. In windmills the wind passes through the airfoil section of the blades and the lift produced generates a torque which is then transformed to electricity in the generator.

4. PARTS

5. TYPES: Marine Current Turbine 750 kW – 1.5 MW 15 – 20 m rotors
3 m monopole
10 – 20 RPM
Deployed in multi-unit farms or arrays
Like a wind farm, but
Water 800x denser than air
Smaller rotors
More closely spaced

6. Tidal Turbines (Swan turbines)
Direct drive to generator
No gearboxes
Gravity base
Versus a bored foundation
Fixed pitch turbine blades
Improved reliability
But trades off efficiency

7. Oscillating Tidal Turbine
Oscillates up and down
150 kW prototype operational (2003)
Plans for 3 – 5 MW prototypes

8. Production of electricity from underwater windmill
The moon's gravitational pull on water bodies creates tides. In turn, this movement creates kinetic energy that is carried by the water
The underwater current produced by the tides spins blades
These turbines are attached to a gear box, which is connected to an electrical generator.

9. UNDERWATER WINDMILL POTENTIAL
The first, and still by far the largest, tidal generating facility was built in northern France in 1966, with an impressive capacity of 50 MW
Similar but much smaller barrage plants--a type increasingly seen as too costly--have been built in Nova Scotia, Canada (10 MW) and in Kislogubsk, near Murmansk, Russia, on the Barents Sea (40 kW).
MCT – 4 to 5MW

10. The rotor should be placed about 20 to 30 meters deep and that currents have a maximum speed of at least 2.25 to 2.5 meters per second.
To get onto the rig, we use a rubber inflatable boat
A key innovative aspect of the Seaflow design is that its gearbox and turbine can be raised above sea level for servicing.

11. Test Bed Characterization
Created flow through scaled model of a tidal turbine in a 100’ long tow tank by attaching test bed to movable carriage
Ran carriage at three controllable speeds and multiple torsional loads
Data is collected.

12. RESULTS
Collected average steady state angular velocity and average torsional load is used to develop dimensional performance curves
Show the precision of the test bed and performance of turbine design.

13. Angular velocity and Avg T.Load

14. Dimensional performance curves

15. Performance of turbine design

16. Conclusion
Data was collected over a range of speeds and it was shown that the non-dimensionalized power curves collapsed to a single performance curve as expected. This was used to validate the performance of the test bed measurement system.

17. Advantages Underwater windmills are relatively cheap to manufacture.
Their environmental impact is negligible
Working tidal turbine can have much smaller diameter rotors than an equivalent power output winds turbine.
It does not depend on the vaguaries of the weather.
More power generated means greater returns on investment
Energy output is a 100℅ reliable, as tides are as sure as the moon.

18. Diasadvantages Most shrouded underwater windmills are directional.
Underwater windmills need to be below the mean low water level
Underwater windmills loads are 3 to 4 times those of the open or free stream turbine, so a robust mounting system is necessary
Shrouded underwater windmills may be hazardous to marine life

19. Conclusion
The Department of Energy has shown great enthusiasm regarding underwater windmill as one of the future energy source. Philosophy regarding energy will change drastically from the present into the future. In a society with increasing energy demands and decreasing supplies, we must look to the future and develop our best potential renewable resource. Underwater windmill fits the bill, a natural source of energy with many benefits. The planet's tidal capability greatly exceeds that of the world’s entire coal and oil supply. It is an ideal source of energy with great potential. When developed underwater windmills could be one of the type which provides energy for our future requirements

20. References [1] en.wikipedia.org/wiki/Tidal_stream_generator
[2] D’Epagnier, Chung, Stanway and Kimball, 2007: An Open sourced Parametric Propeller Design Tool; MTS/IEEE Oceans Conference, Vancouver, B.C.
[3] Zeh,M.: Development of a Six Axis Dynamometer for Tow Tank Testing; Undergraduate Capstone Project, April 2006 Maine Maritime Academy, Castine Me.
[4] W. Li, “Using the Current Generation of ‘Underwater Turbine’ Through
experiments,” Small and Medium-Sized Enterprise Technolony. China, vol. 7, pp. 11–11, May 2006.
[5] Garrett, C. and Cummins, P. (2005). "The power potential of tidal currents in channels." Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, Vol. 461, London. The Royal Society, 2563–2572.
[6]
[7] Shulman, Robin (September 20, 2008). "N.Y. Tests Turbines to Produce Power"
[8]
[9]

21. Thank you