tobermoryphil
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How would you ever recognise it if there was?
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Merged DDWFTTW in a “Real” Wind
- Thread starter ynot
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How would you ever recognise it if there was?
What is this "inertial influence of the planet earth" of which you speak?
-- Roger
Ummm, yes he does. Here is the quote again:
"At this point the less informed among the cart crowd will say I have just shown the cart works, because the thrust is 250 N and the drag is 174 N, right? No, forces alone are not the whole story as we need to consider energy and power. The thrust force is what would be there IF and only IF, there is sufficient energy in the system to develop and sustain that thrust."
No I don't see. Are you saying that if someone is right about one thing than they are therefore right about all things?
You really don't get it, do you?
Oh, like the Javaprop data that was deliberately misleading?
The NALSA trial says 32N constant, and there is not one calculation that comes close to that figure, and all rise with speed.
I can post anywhere, and will.
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wrong
I have the math, I have presented it several times, you just don't understand it.
Was this a Prof quote?
"At this point the less informed among the cart crowd will say I have just shown the cart works, because the thrust is 250 N and the drag is 174 N, right? No, forces alone are not the whole story as we need to consider energy and power. The thrust force is what would be there IF and only IF, there is sufficient energy in the system to develop and sustain that thrust."
Wasn't this a Profpangloss quote? It seems way too articulate to be Humber.
Regards,
WindGrins
"At this point the less informed among the cart crowd will say I have just shown the cart works, because the thrust is 250 N and the drag is 174 N, right? No, forces alone are not the whole story as we need to consider energy and power. The thrust force is what would be there IF and only IF, there is sufficient energy in the system to develop and sustain that thrust."
Wasn't this a Profpangloss quote? It seems way too articulate to be Humber.
Regards,
WindGrins
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tobermoryphil
Thinker
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- Apr 23, 2011
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- 172
Ah, Javaprop are now in on the conspiracy too!
Funny you should say not one calculation comes anywhere near 32 N, just after I posted a calculation with a result of 33 N!
However, (Propfloss'?) figure that I used of 111 N at 9 m/sec for 1 KW is arbitary; it could just as easily be 3 kw we take out.
So, lets use 93% transmission efficiency again; same prop, revs, etc., but 2790 W input; thrust is now 485 N.
Retarding forces are 333 N, plus the same 63 N rolling and air resistance, so a total of 393 N.
We now have 85 N of spare thrust to accelerate the cart.
Also arbitary; I agree the actual energy input from slowing the wind has to be quantified to get realistic figures.
So keep on posting wherever you like, Humber- I expect the next one will be on the lavatory wall.
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"At this point the less informed among the cart crowd will say I have just shown the cart works, because the thrust is 250 N and the drag is 174 N, right? No, forces alone are not the whole story as we need to consider energy and power. The thrust force is what would be there IF and only IF, there is sufficient energy in the system to develop and sustain that thrust."
Wasn't this a Profpangloss quote? It seems way too articulate to be Humber.
Regards,
WindGrins
Yes, it was from his analysis posted over at TR. I quoted the whole analysis in post 6017 for fttw.
Yes. I know. And there are three things you should know.
1) He used Carteer numbers. Devil's Advocate
2) He says "if"
3) I posted that I thought it was a mistake to continue to adopt the Carteerian way, and that Yevgheni did not agree with the idea at all. He affirmed that he did not agree.
Do you think that someone who trenchantly disagrees with the entire idea is going to agree with the idea, or that you can erase the bogus trial and its 100 degree winds by mining for a word or two?
NALSA? I had never heard of them.
I thought the first part made sense. I don't see why if the thrusts work out you need to go on to consider the energy, but if you do, I think adding in extra drag at the rear wheel to get the 174N figure is incorrect. If that was the real drag at the rear wheel it should have been used in the first place instead of assuming 1kW and calculating 110N. That would make both analyses indicate that the cart would slow down; however even that, because of the real-world inefficiencies assumed in the analysis, wouldn't speak to the physicality of the situation.
This is actually somewhat interesting.
PPG:"At this point the less informed among the cart crowd will say I have just shown the cart works, because the thrust is 250 N and the drag is 174 N, right? No, forces alone are not the whole story as we need to consider energy and power. The thrust force is what would be there IF and only IF, there is sufficient energy in the system to develop and sustain that thrust."
This is actually interesting and shows some a serious lack of understanding of a "cart before the horse" variety. The excess thrust is what produces the energy/power to accelerate the cart.
As I stated earlier, any competent energy or power analysis would be consistent with a force calculation. So the the premise put forward makes no sense:
PPG"The thrust force is what would be there IF and only IF, there is sufficient energy in the system to develop and sustain that thrust."
A reasonable way to state something meaningful would be that for the system to have the energy to accelerate, the force calculation must show excess sustained force (above losses) to increase the cart's KE since work =F*D.
Regards,
WindGrins
PPG:"At this point the less informed among the cart crowd will say I have just shown the cart works, because the thrust is 250 N and the drag is 174 N, right? No, forces alone are not the whole story as we need to consider energy and power. The thrust force is what would be there IF and only IF, there is sufficient energy in the system to develop and sustain that thrust."
This is actually interesting and shows some a serious lack of understanding of a "cart before the horse" variety. The excess thrust is what produces the energy/power to accelerate the cart.
As I stated earlier, any competent energy or power analysis would be consistent with a force calculation. So the the premise put forward makes no sense:
PPG"The thrust force is what would be there IF and only IF, there is sufficient energy in the system to develop and sustain that thrust."
A reasonable way to state something meaningful would be that for the system to have the energy to accelerate, the force calculation must show excess sustained force (above losses) to increase the cart's KE since work =F*D.
Regards,
WindGrins
From Spork, who according to you, must also be a conspirator.
Thrust= 49.9167099(lbs)
Torque= 124.131477(ft-lb)
Power= 2.83614945 (HP)
2100W
vc=18*1.467 (this is 18 mph airspeed)
omega=120 RPM
That is for an airspeed of 18mph, and not for a land speed of 28mph. The cart does not run at 120mph at 28mph, but 75 - 80rpm so all numbers are inapplicable to the cart.
The gears force a relationship between airspeed and AV, that has no theoretical support, and certainly not from Javaprop. The author of that programme, definitively says that props do not screw through the air.
Propeller power demand rise as the cube of AV, and the supposed wheel power will rise linearly with AV
None of the numbers are close to reality, or predict a constant net force, because they are ad-hoc fabrications.
AND THE WIND CHANGES 100 DEGREES.
1) There were no "carteer numbers"
2) He did not say if.
3) You had nothing to do with the post. He said he agrees with the force calcs but says that it is not the "whole story as we need to consider energy and power".
How many times do I have to post the quote before you read it?
PPG:"At this point the less informed among the cart crowd will say I have just shown the cart works, because the thrust is 250 N and the drag is 174 N, right? No, forces alone are not the whole story as we need to consider energy and power. The thrust force is what would be there IF and only IF, there is sufficient energy in the system to develop and sustain that thrust."
This is actually interesting and shows some a serious lack of understanding of a "cart before the horse" variety. The excess thrust is what produces the energy/power to accelerate the cart.
As I stated earlier, any competent energy or power analysis would be consistent with a force calculation. So the the premise put forward makes no sense:
PPG"The thrust force is what would be there IF and only IF, there is sufficient energy in the system to develop and sustain that thrust."
A reasonable way to state something meaningful would be that for the system to have the energy to accelerate, the force calculation must show excess sustained force (above losses) to increase the cart's KE since work =F*D.
Regards,
WindGrins
Good, then you will like the next analysis.
Subduction Zone
Muse
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That is not the first time Harold misused the term "inertia". He talked of inertia building up on the treadmill too. For someone who supposedly does not believe no perpetual motion this is a rather strange concept. Since inertia is equivalent to mass his belief that the treadmill can increase inertia is the same as believing that the treadmill can create mass out of thin air. And long ago Einstein showed that there is a relationship between mass and energy. In other words the one person who seems to believe in energy coming out of nowhere is Haryevchrischroderppg
PPG:"At this point the less informed among the cart crowd will say I have just shown the cart works, because the thrust is 250 N and the drag is 174 N, right? No, forces alone are not the whole story as we need to consider energy and power. The thrust force is what would be there IF and only IF, there is sufficient energy in the system to develop and sustain that thrust."
This is actually interesting and shows some a serious lack of understanding of a "cart before the horse" variety. The excess thrust is what produces the energy/power to accelerate the cart.
As I stated earlier, any competent energy or power analysis would be consistent with a force calculation. So the the premise put forward makes no sense:
PPG"The thrust force is what would be there IF and only IF, there is sufficient energy in the system to develop and sustain that thrust."
A reasonable way to state something meaningful would be that for the system to have the energy to accelerate, the force calculation must show excess sustained force (above losses) to increase the cart's KE since work =F*D.
Regards,
WindGrins
I agree. That's why I keep posting that I find his math so hilarious.
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