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Mess with your minds: A wind powered craft going faster than a tail wind speed.
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Labrat101:

--- Quote from: gnuarm on December 31, 2021, 06:36:00 pm ---I don't follow at all about the front wheels lifting for lower drag causing the car to accelerate.  Do you mean the drag of the wheels on the road?

--- End quote ---
I think you will find the blackbird gearbox is on the back wheels as I remember it's a chain and cog drive . So the front wheels are only for supporting the front & steering..
In thrust the noise will lift . It's an aerodynamics it will rise against thrust due to centrifugal force from the prop and air under the fuselage.
I am Not going into a mile of advanced math in aerodynamics.  Take it as is . It does and will.
 
IanB:

--- Quote from: Labrat101 on December 31, 2021, 07:18:29 pm ---I think you will find the blackbird gearbox is on the back wheels as I remember it's a chain and cog drive . So the front wheels are only for supporting the front & steering..
In thrust the noise will lift . It's an aerodynamics it will rise against thrust due to centrifugal force from the prop and air under the fuselage.
I am Not going into a mile of advanced math in aerodynamics.  Take it as is . It does and will.

--- End quote ---

But it doesn't really matter, and has no relevance to anything important about how the vehicle works. So it is best left to one side, or it will just become another red herring to divert the discussion.
Labrat101:
Ok
Can I just say I need to know how
Much energy is required to open a bottle
Of good whiskey and get drunk.
Happy new year 🎉
..
No more off topics.  :popcorn:
fourfathom:

--- Quote from: IanB on December 31, 2021, 07:17:27 pm ---Remember that gearing can be placed between the motor and the wheels. [...]
--- End quote ---

No, I'm comfortable with all that, it's just the fundamental discussion of work, energy, force, etc.  And I'm actually pretty good with those as well.  It's just where does the motor (or solenoid) power go, if not into motion?  I think the answer is "heat".

As for upwind, I see no need to bring that in, other than as an interesting implementation detail.  Direct upwind movement, using a vehicle-mounted wind-driven generator (or mechanical gear drive) is easy to demonstrate and understand.  Okay, I suppose we can also consider DDWFTTW as "upwind", so perhaps some insight into the question can be gleaned.

And why bother discussing feathering props?  Yes, these can improve efficiency, but fixed-props have been shown to work in DDWFTTW tests.

IanB:

--- Quote from: fourfathom on December 31, 2021, 08:11:26 pm ---No, I'm comfortable with all that, it's just the fundamental discussion of work, energy, force, etc.  And I'm actually pretty good with those as well.  It's just where does the motor (or solenoid) power go, if not into motion?  I think the answer is "heat".
--- End quote ---

Right, but the key thing is the motor the doesn't need any input power if the vehicle is stationary, because the vehicle is held in place by the gears that can't turn backwards. So from that stationary starting position, any tiny bit of power applied to the motor can make it turn forwards. There is no need for any "holding torque" on the motor to waste power as heat.

But clearly if you stall an electric motor by preventing it from turning when applying power, then the electrical power will be dissipated in the windings as heat (and may burn out the motor if it persists for too long).
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