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Automotive Electric car with the wind mill

  1. Feb 25, 2012 #1
    I am mechanical engineer and working on a project of electric car havin a wind mill on the top.
    i am using 7 lead acid batteries and a DC series wound motor. The car has a wind mill for the recharging of the batteries.
    I have read other thread on this forum which states that the wind mill on the car is not a productive idea.
    so whether it will be a good idea to use the wind mill only at the time when the car is parked. so that drag doesn't cause any work loss??
    and how much size and the power wind mill i should be using???

    Any relevant input will help
  2. jcsd
  3. Feb 27, 2012 #2


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    Science Advisor
    Gold Member

    If you are a mechanical engineer as you claim to be, you should go through a simple thermodynamic analysis which shows your system and where the power inputs are. You'll find that the only way the windmill can "provide" power to the system is for it to sap it from the car's speed as wind drag, and this speed has to have been added to the car by the engine. This means your windmill is just adding drag to the system and not providing power.

    You're wasting your time, save yourself the embarassment and stop while you're behind.
    Last edited: Feb 27, 2012
  4. Feb 27, 2012 #3


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    Staff: Mentor

    If you want to use the wind to help recharge the batteries when the car is stationary, that could work. However, it would take a pretty large windmill, and it would need to be pretty windy. You could have a stationary windmill at your home, for example, that you plug your car into when it is parked. You would definitely not want the windmill out in the windstream while you were driving!
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