1. Gandhinagar Institute of Technology Guided By: Prof. Amit Patel
Active Learning Assignment
Topics: “Introduction to Flywheels ”
Name
Enrollment no
Dave rushabh
Patel Deep
Deepak Kumar
Branch : Mechanical Engineering
Div: A
Guided By: Prof. Amit Patel

2. Introduction :-
A flywheel is a rotating mechanical device that is used to store rotational energy.
A flywheel is such a device which is attached to an engine, reciprocating, compressors, pumps etc.
Flywheel store energy mechanically in the form of kinetic energy.
Flywheels are one of the most promising technologies for replacing conventional lead acid batteries as energy storage system.

3. Flywheel is basically a rechargeable battery.
It is used to absorb electric energy from a source, store it as kinetic energy of rotation, and then deliver it to a load at the appropriate time, in the form that meets the load needs.
Power in
Input
electronics
Motor
Flywheel
Output
electronics
Generator
Power out

4. What does it do?
A flywheel at its most basic is a device to store energy. In the case of a flywheel used in automotive applications, it actually serves several purposes.
First, it does store energy to help smooth out the torque and power flow of the engine as it runs through its combustion cycles. The flywheel gains energy as the engine accelerates, and stores it as rotational kinetic energy.
It then gives some of that energy back to the system to help create momentum to carry the crank and pistons through the compression cycle and help optimize power delivery.
Secondly, the flywheel also helps deliver rotational and torsional stability and balance to the engine’s rotating assembly (crank, rods pistons, etc.) in order to help the engine run smoother and reduce wear.

5. It releases this energy between power impulses, and fluctuations in speed and smoother engine operation. The flywheel is mounted at the rear of the crankshaft near the rear main bearing
The flywheel on large, low-speed engines is usually made of cast iron. This is desirable because the heavy weight of the cast iron helps the engine maintain a steady speed. Small, high-speed engines usually use a forged steel or forged aluminum flywheel for the following reasons:
(1) The cast iron is too heavy, giving it too much inertia for speed variations necessary on small engines.
(2)Cast iron, because of its weight, pulls itself apart at high speeds due to centrifugal force.

6. Construction of Flywheel :-
Flywheels are typically made of steel and rotate on conventional bearings; these are generally limited to a revolution rate of a few thousand RPM.
The number of arms depends upon the size of the flywheel and its speed of rotation. But the flywheels above 2-5 meters are usually casted in two pieces. Such a flywheel is known as “ split flywheel”

7. Types of Flywheels :- Flywheels are of two types as follows
Disc type flywheel
Rim type flywheel

8. Otto engine and single cylinder desiel engine

9. Street car
The Connelly Compound Gas Engine: 1888 This is the intended application of Connelly's compound engine to a street-car. The engine is partly hidden behind the large fly-wheel and the variable-ratio friction disc, but the horizontal LP cylinder can be seen to the lower right.
The variable-ratio drive was intended to give full control of speed and forward/reverse by one lever. While it was relatively sophisticated, in that the friction wheel contact pressure was varied with the amount of power transmitted, it seems highly unlikely that it could have been made to work for very long.

11. Applications Typical applications for flywheels include;
Dynamic balancing of rotating elements.
Energy storage in small scale electricity generator sets.
Automotive applications such as clutches.

12. One Important point
A flywheel's momentum can be increased either by making it heavier or by getting it to spin faster.
In the past flywheels used for more ambitious energy-storing purposes have tended to be bulky.
That is because at speeds above several thousand revolutions per minute (rpm) the materials they were made of could disintegrate.
This made them practical for applications in which size does not matter much, such as balancing loads across power grids.
They have only found one widespread use in transport: on trains, where they propel some locomotives across gaps in the power rail

13. Advance and Modern Flywheel
Advanced flywheels are also now used for protecting against interruptions to the national electricity grid.
The flywheel provides power during period between the loss of utility supplied power and either the return of utility power or the start of a sufficient back-up power system
Flywheels have also been proposed as a power booster for electric vehicles. Speeds of 100,000 rpm have been used to achieve very high power densities.
Modern high energy flywheels use composite rotors made with carbon-fibre materials. The rotors have a very high strength-to-density ratio, and rotate at speeds up to 100,000 rpm. in a vacuum chamber to minimize aerodynamic losses.

14. Like the V60 PHEV and unlike most hybrids on the market today, the conventional and unconventional "motors" are separate. In this car, a production turbocharged four-cylinder gasoline engine drives the front wheels while the flywheel KERS unit drives the rear wheels.
The operation is fairly simple. Under braking, the wet clutch closes and the KERS drags on the rear wheels to spin up the flywheel.
When moving off again, the clutch closes again and feeds the mechanical energy from the spinning flywheel back to the rear wheels to move the car forward. While not currently designed to do so, Volvo says the KERS has enough energy to move the car from a stop. It can already power the car under light throttle to maintain speed.

16. Use of Flywheel in NASA
NASA use the flywheel for deep space propulsion

17. Benefits in Aerospace
Flywheels are preferred over conventional batteries in many aerospace applications because of the following benefits:
5 to 10+ times greater specific energy
Lower mass / kW output
Long life. Unaffected by number of charge / discharge cycles
85-95% round trip efficiency
Fewer regulators / controls needed
Greater peak load capability
Reduced maintenance / life cycle costs

18. Single acting cylinder
Double acting cylider application of fly wheel

19. Lets discuss about working of flywheels of heavy vehicles

24. Conclusion :-
Flywheels are one of the most promising technologies for replacing conventional lead acid batteries as energy storage systems for a variety of applications, including automobiles, economical rural electrification systems, and stand-alone, remote power units commonly used in the telecommunications industry.
Recent advances in the mechanical properties of composites has rekindled interest in using the inertia of a spinning wheel to store energy.

25. Abstract
In developing countries like India, with rapid growth in the economy, the demand for electricity is
also increasing. As the renewable energy percentage increases in the total energy mix, the inherent
intermittency and variability of renewable energy sources poses a challenge when these energy
sources are integrated. This is where energy storage becomes very critical as it improves the
dispatch rate of the electricity generated by renewable energy resource. With the rising demand for
reliable, cost-effective, and environmentally friendly energy storage, the Flywheel Energy Storage
System (FESS) is quickly coming into its own. This study presents an analysis which shows that using
an FESS is a promising alternative in mitigating energy storage problems in decentralized electricity
generation projects where an uninterrupted power supply (UPS) is required. With the help of
HOMER simulations, we have tried to establish that energy storage through flywheel is a viable
option.

26. Conclusion of research paper:-

27. Refernce