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

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electrodacus:

--- Quote from: fourfathom on September 17, 2021, 09:19:45 pm ---I am now halfway through this entire thread, and I apologize to all for beating a thoroughly dead horse.

--- End quote ---

The crowd effect is quite a bad thing especially here when the majority is wrong.

Kleinstein:

--- Quote from: electrodacus on September 17, 2021, 08:06:10 pm ---Have you watched my slow motion video https://odysee.com/@dacustemp:8/wheel-cart-energy-storage-slow:8
The energy storage is fairly visible there and you can see vehicle peak speed even above paper speed but average speed is much lower. Same will happen to blackbird if you waited long enough to see multiple cycles then it will look the same as my toy cart.

--- End quote ---
I watched the video, and when taking the paper as the reference and the ground as the driving system, the average velocitiy is larger - the vehicle moved to the right in the picture after all, so more to the right than the ground has moved.
The movement is a bit jerky, because the paper is not moved at a constant speed. Move the paper at a constant speed and vehicle would also more at a constant speed.


--- Quote from: electrodacus on September 17, 2021, 08:06:10 pm ---There can not be a sustained speed above wind speed and that I what I try to make people understand.

--- End quote ---
However this is only a claim and not a valid argument. This claim is also wrong - any most of us here have recognized this and try to explain how it is possible. The videos show it - just believe what you see and don't thing it is the red hering making this happen. It is much simpler.

electrodacus:

--- Quote from: Kleinstein on September 17, 2021, 09:31:33 pm ---
--- Quote from: electrodacus on September 17, 2021, 08:06:10 pm ---Have you watched my slow motion video https://odysee.com/@dacustemp:8/wheel-cart-energy-storage-slow:8
The energy storage is fairly visible there and you can see vehicle peak speed even above paper speed but average speed is much lower. Same will happen to blackbird if you waited long enough to see multiple cycles then it will look the same as my toy cart.

--- End quote ---
I watched the video, and when taking the paper as the reference and the ground as the driving system, the average velocitiy is larger - the vehicle moved to the right in the picture after all, so more to the right than the ground has moved.
The movement is a bit jerky, because the paper is not moved at a constant speed. Move the paper at a constant speed and vehicle would also more at a constant speed.


--- Quote from: electrodacus on September 17, 2021, 08:06:10 pm ---There can not be a sustained speed above wind speed and that I what I try to make people understand.

--- End quote ---
However this is only a claim and not a valid argument. This claim is also wrong - any most of us here have recognized this and try to explain how it is possible. The videos show it - just believe what you see and don't thing it is the red hering making this happen. It is much simpler.

--- End quote ---

The paper is moved at fairly constant speed and it is not the reason for the type of movement. Please look closer at the video as you will see paper always moves at a decently constant speed while vehicle just stops many times.
Not that vehicle needs to stop to demonstrate what I'm saying it can just speed up and slow down as it is the case with the gear version of the vehicle where there was less energy storage so the elastic/springy type of storage is smooth out by the vehicle kinetic energy that will no longer be zero when it starts to move.

If you understand what you see in this video then you will also understand how blackbird works is just that blackbird has so much larger energy storage and lower friction that cycle is hundreds of seconds instead of hundreds of milliseconds.
Look at the front wheel turning while back wheel is stationary. Is clear energy from front wheels is stored in the rubber band since that is stretched.
Then when front wheel starts to slip the stored energy is what is used to push the vehicle forward using the back wheels.
If there was no energy storage the front wheel will never turn without the back wheel also turning and since that can not work the front wheel will just slip in best case so vehicle will not move at all else vehicle will move backwards right to left as in my theoretical example.
In practice is a bit hard to get rid of both friction and energy storage.
Paper moves at least 2x faster from right to left than the vehicle moves from left to right in average but there are peaks where vehicle may move faster than paper in the opposite direction but the average speed is what counts and that is why a sail vehicle will win against a blackbird type vehicle if wining means getting first to finish line.

ejeffrey:

--- Quote from: electrodacus on September 17, 2021, 02:06:13 pm ---
--- Quote from: IanB on September 17, 2021, 07:43:30 am ---
--- Quote from: electrodacus on September 17, 2021, 03:49:04 am ---Do you not agree with that fact that all air molecules move in the opposite direction of travel when vehicle is above wind speed traveling in the wind direction?
--- End quote ---
No, we do not agree.

--- End quote ---

Please provide details if you do not agree.
My statement is not only very simple but also correct so I wait for you explain how my statement is incorrect

--- End quote ---

We do not agree that there is an apparent violation of conservation of energy -- because there isn't: the vehicle extracts energy from the velocity difference between the wind and the ground and uses that to make the vehicle go faster.

We don't agree that kinetic energy is a vector.  Because it is not, as taught in every physics class since Newton.   Momentum is a vector, kinetic energy is a scalar.  This is your most fundamental, most wrong misunderstanding of basic physics. See: Kinetic energy is a scalar

We don't agree that "the resultant velocity must be in the direction of the net work" because that is a meaningless statement based on the above two points.

We don't agree that energy storage beyond the kinetic energy of the vehicle is relevant in any of the demonstrations because they are not, and you have not been able to quantify or explain them

We solved the free body diagram to find the net torque and direction of motion of the mechanical analog.  You don't agree that we did math correctly, but you didn't explain why other than your misguided "net work" argument.

And now that you finally agree that a moving piece of paper is equivalent to a treadmill, you have invented a new energy storage theory that also makes no sense.  I did the experiment you said would prove you right or wrong, it proved you wrong, and you don't believe it.  I was sitting right there and I can tell you that the belt was stretching a negligible amount and not storing energy.

Multiple experiments demonstrate that you are incorrect, so yes we disagree.

electrodacus:

--- Quote from: ejeffrey on September 17, 2021, 10:50:27 pm ---
We do not agree that there is an apparent violation of conservation of energy -- because there isn't: the vehicle extracts energy from the velocity difference between the wind and the ground and uses that to make the vehicle go faster.

We don't agree that kinetic energy is a vector.  Because it is not, as taught in every physics class since Newton.   Momentum is a vector, kinetic energy is a scalar.  This is your most fundamental, most wrong misunderstanding of basic physics. See: Kinetic energy is a scalar

We don't agree that "the resultant velocity must be in the direction of the net work" because that is a meaningless statement based on the above two points.

We don't agree that energy storage beyond the kinetic energy of the vehicle is relevant in any of the demonstrations because they are not, and you have not been able to quantify or explain them

We solved the free body diagram to find the net torque and direction of motion of the mechanical analog.  You don't agree that we did math correctly, but you didn't explain why other than your misguided "net work" argument.

And now that you finally agree that a moving piece of paper is equivalent to a treadmill, you have invented a new energy storage theory that also makes no sense.  I did the experiment you said would prove you right or wrong, it proved you wrong, and you don't believe it.  I was sitting right there and I can tell you that the belt was stretching a negligible amount and not storing energy.

Multiple experiments demonstrate that you are incorrect, so yes we disagree.

--- End quote ---

Obviously there is no violation of conservation of energy just your explanation if it where to be true (it is not) will violate the conservation of energy.

If you know the vehicle weight and kinetic energy you can find out the speed. Since weight is constant we can agree that a drop in kinetic energy will result in a drop of speed so when I use vehicle kinetic energy I'm using that to demonstrate that speed can not increase.
The wheel only vehicle has mostly kinetic energy stored in vehicle but in case of the propeller version the propeller kinetic energy is significant and needs to be considered.
Using forces only is your main problem as force on the wheel is not the same with force on vehicle when gear ratio is different from 1:1.
I do not invent anything it is super clear from my video that without energy storage the vehicle can not move from left to right. If you do not see that please look closer and try to find anything else that will allow vehicle to move from left to right.

How can you say the belt is not storing energy ?  Negligible amount is your definition but I will say sufficient not negligible.  This is a ultra small ultra light vehicle and in slow down video it is clearly seen how vehicle stop's and starts multiple times (same as back wheel) while front wheel always rotates.
Multiple experiments are interpreted incorrectly. None of the experiments contradict my explanation.

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