Maximizing Car Efficiency: Utilizing Flywheels for Rotational Motion

In summary, the conversation discusses the use of a flywheel to convert linear motion into rotational motion in cars. It is suggested that this could potentially be used to replace brakes and fuel, but it is not practical due to limitations in energy storage and conversion time. However, it can supplement both brakes and fuel, making it a useful addition to a car's power system. Some examples of where this technology is currently being used, such as in F1 racing and flywheel-powered buses, are also mentioned.
  • #1
omar alaa
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can we convert the linear motion into rotational motion in cars using a fly wheel under the car ?
 
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  • #2
omar alaa said:
can we convert the linear motion into rotational motion in cars using a fly wheel under the car ?

Certainly. It would be simpler to use the regular wheels. Look up regenerative braking.
 
  • #3
ok but will it replace the brakers ,its impossible as how would they convert the great linear kinetic energy of the car into rotational energy in very short time ? would the fly wheels replace fuel and brakes ?
 
  • #4
See..

http://en.wikipedia.org/wiki/Kinetic_energy_recovery_system

KERS could in theory be used to replace brakes but I believe it's hard to make a KERS system work efficiently over a wide speed range and there is the safety issue - what happens if the KERS system fails?

KERS would save fuel in a road car but you have to work out if the extra weight of the KERS system is going to effect performance in other ways. I believe many electric cars have regenerative braking/KERS as they already have most of what's needed to add KERS anyway.

Instead of saving fuel the F1 motor racing rules allow the recovered energy to be used to provide a short burst of extra power to make overtaking easier.

These days all F1 cars use an electrical system where the energy is stored in batteries, however the Williams team did develop a flywheel based system which is still used but not in F1..

http://www.williamshybridpower.com/
 
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  • #5
omar alaa said:
ok but will it replace the brakers ,its impossible as how would they convert the great linear kinetic energy of the car into rotational energy in very short time ? would the fly wheels replace fuel and brakes ?

It works the other way with motor cars, where the rotational energy of the engine is converted to linear Kinetic Energy.
Also, there are 'flywheel powered buses' which are 'charged up' by spinning a flywheel at the terminus and they make it round their route. A clutch is used to engage and disengage the drive for the wheels. I don't think regen braking is used, though.
It is difficult to do away with brakes completely because it's difficult to produce the level of negative acceleration that braking requires. You need around -1g for breaks whereas an engine only needs to give say g/5, for passenger comfort.

The transmission system would need to be very robust for a flywheel to do this and you would also need a very flexible gear system. Doing it electrically is probably the best way. (You couldn't do without brakes!)
 
  • #6
omar alaa said:
ok but will it replace the brakes , its impossible as how would they convert the great linear kinetic energy of the car into rotational energy in very short time ? would the fly wheels replace fuel and brakes ?

The flywheel replaces neither fuel nor brakes, although it supplements both.

It can't completely replace the fuel because you need some way of getting the car and the flywheel moving when the flywheel is completely spun down, because a practical flywheel cannot store nearly as much energy as an equivalent weight of fuel, and because a flywheel large enough to completely replace the fuel tank would take much longer to spin up to speed than it takes to refill the fuel pump.

It can't completely replace the brakes, both because of the possibility of mechanical failure and because (as you surmise) it's not practical to convert all the kinetic energy of a moving vehicle in the time needed to do a full controlled panic stop. However, most driving doesn't involve panic stops, and recovering the kinetic energy in those cases instead of wasting heating up the brake pads, is advantageous.

You might want to google for "Porsche 911 GT3 R", see what you find.
 

1. How do flywheels improve car efficiency?

Flywheels store rotational energy, which can be used to power the car's engine and reduce the amount of fuel needed to operate the vehicle. This results in improved efficiency and fuel economy.

2. How does the use of flywheels impact driving performance?

Flywheels can provide additional torque to the car's engine, resulting in improved acceleration and overall performance. They can also help to stabilize the car's speed and reduce engine strain during gear shifts.

3. Are there any limitations to using flywheels in cars?

One limitation is the added weight and size of the flywheel, which can affect the car's handling and maneuverability. Additionally, flywheels can only store a limited amount of energy, so they may not be as effective for longer trips or frequent stops and starts.

4. How does the cost of flywheel technology compare to other methods of improving car efficiency?

The cost of implementing flywheel technology in cars can vary depending on the specific design and materials used. However, in general, it is relatively more expensive compared to other methods such as hybrid or electric vehicles.

5. Are there any safety concerns associated with using flywheels in cars?

Proper engineering and design are essential to ensure the safe use of flywheels in cars. One potential safety concern is the risk of the flywheel disintegrating in the event of a crash or failure. However, with proper precautions and testing, this risk can be minimized.

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