Questions about material for flywheel storage in automotive field

[Vacre]

Hello
I have composed some figures for a flywheel system that would be used in a custom car and involve multiple flywheels. The vehicle would be use the flywheels for energy storage and recovery, and would be powered by electric engines placed on the drive axles. These flywheels would be magnetically levitated, and operate in a vacuum, and have a group shielding (as opposed to an individual shielding for each). I would expect the flywheels to be magnetically levitated, and shielded as a group in a L:60 x W:30 x H:33 box of mild steel that is at least half an inch thick (although I am not sure if that is too much or too little).

I am considering multiple flywheels because a single flywheel would incur weight issues (with the flywheel itself and the system), gyroscopic issues, and shielding issues, I have decided to divide the power into multiple flywheels. There would be at least 18 flywheels.

Gyroscopic forces: dividing the total energy into 18 flywheels and then spinning 9 clockwise and spinning the other 9 counter- clockwise would help mitigate negative effects. Placing the flywheels in a containment system that is not rigidly mounted to the vehicle would also help.
Shielding: increasing the number of flywheels should help by decreasing the amount of material in the event of a failure. The division of energy among flywheels also involves decreasing the amount of energy that would be output by one, massive flywheel in the event of a failure.

But I am not familiar with specific carbon fiber materials and wanted to know what sort of energy storage I could achieve with a flywheel has a 27- inch diameter, a low moment of inertia, and up to a one- inch thickness. The thickness is not fixed because I am not sure what I can get out of a .3- inches thick flywheel versus a one- inch thick flywheel. I considered the 27- inch diameter because of some figures I made using a bicycle tire physics unit I found online.

I have looked at some sources and understand that the essential ceiling for flywheel rotation is 100, 000 rpm. The flywheels being used in Kinetic. Energy. Recovery. Systems. (Formula One, Porsche GT3 R Hybrid) typically have 40k rpm limits, but they also have low energy capacities of around .2 kilo-watt hours. I would like to get at least one kWh per flywheel, and this would require a higher rpm level of maybe 65k to 85k rpm. This high rpm is the reason I considered carbon fiber.

I would be grateful if someone could provide the dimensions of the flywheel that could achieve this (the diameter does not have to be 27 inches), material to be used, cost of the flywheel, and energy capacity equaling at least one kilo-watt hour.

Thank you

 

[Achy47]

for sharing your ideas and calculations for this flywheel system. It sounds like you have put a lot of thought into the design and potential challenges. I can offer some insights and suggestions for your project.

Firstly, it is important to consider the weight and size limitations for your custom car. The more flywheels you add, the heavier and larger the system will become. This could potentially impact the performance and handling of the car. It would be beneficial to do some calculations and simulations to determine the optimal number of flywheels for your specific car and energy needs.

In terms of material, carbon fiber is a good choice for flywheels as it is lightweight and strong. However, it can be expensive and difficult to work with. You may also want to consider using a combination of materials such as carbon fiber and aluminum to achieve the desired energy storage and rotation speed.

As for the dimensions, the size of the flywheel will depend on the material used and the desired energy storage capacity. A thicker flywheel will have a higher energy capacity, but it will also require more energy to spin it at high speeds. It would be helpful to consult with a materials engineer or conduct some experiments to determine the optimal thickness for your flywheel.

In terms of cost, it is difficult to provide an estimate without knowing the specific materials and design of the flywheel. However, using lightweight and durable materials such as carbon fiber may increase the cost.

Overall, it seems like you have a solid foundation for your flywheel system and with some further research and experimentation, you can determine the best dimensions, materials, and cost for your project. Good luck!