Raptor Aircraft

jsstevens said:
He repeated, word for word, his exact lecture section that I didn't understand in the first place.
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Some people find teachers and professors like this "cool" or appealing for some reason. In my opinion, people like that are @$$holes.. obviously if someone is going to office hours it's because they are proactively looking for additional help and tutelage.. repeating the lecture word for word is at best lazy, and at worst a passive aggressive of making the student feel bad

Richard Feynman was known not only for his outstanding contribution to science and theoretical physics, but for his ability to teach. The best teachers out there have a talent for getting their students to get to that "ah, I get it!" point
 
jsstevens said:
My first college Calculus professor (who may have been a great mathematician but was a lousy teacher!) once finished an example on the board and said "This result is obvious. [about a 3 second pause] To those who know it I suppose."
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The favorite lazy professor blow-off line from my days in engineering school was: "...and from here, the solution is intuitively obvious."
 
jsstevens said:
I went to this Calculus professor for help during office hours. He repeated, word for word, his exact lecture section that I didn't understand in the first place. He did that multiple times.
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:D

I think I had that same professor.
 
kyleb said:
The favorite lazy professor blow-off line from my days in engineering school was: "...and from here, the solution is intuitively obvious."
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my “favorite” professor was the one who made us buy a 300.00 textbook...that we ended up never using. Any guesses on who the author was?
 
Tantalum said:
Richard Feynman was known not only for his outstanding contribution to science and theoretical physics, but for his ability to teach. The best teachers out there have a talent for getting their students to get to that "ah, I get it!" point
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My sister got her BS in Physics from Caltech and had Richard Feynman as a professor. He was, according to her, as good as they say.
 
nauga said:
"...to even the most casual observer."

Nauga,
same attitude, different professors
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On the other hand, I was lucky enough for this guy to be one of my Freshman Calculus professors. Brilliant, approachable, and a really good lecturer. He got a standing ovation at the end of his last lecture of the quarter.

https://en.wikipedia.org/wiki/Michael_Barnsley
 
1RTK1 said:
In one bio/chem class, english was the professors third or forth language.:(
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It's always bothered me too..
jsstevens said:
My sister got her BS in Physics from Caltech and had Richard Feynman as a professor. He was, according to her, as good as they say.
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Hey that's pretty cool! The dude is a legend
 
Omalley1537 said:
my “favorite” professor was the one who made us buy a 300.00 textbook...that we ended up never using. Any guesses on who the author was?
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You may have forgotten the required study guide and lab workbook from the same author. Had a couple of these. Oh yeah they were both stapled mimeographed pages for $50 & $100!
 
This most recent video he says he’s trying to push 43 psi out of one of the turbos. That’s insanity for that engine.
 
jaxcessnadriver said:
This most recent video he says he’s trying to push 43 psi out of one of the turbos. That’s insanity for that engine.
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He’s pushing at least 60psi worth of hot air out of his mouth, lol

He must be going for the illustrious combo of early-80’s Reno Unlimited reliability coupled with low performance...
 
jaxcessnadriver said:
This most recent video he says he’s trying to push 43 psi out of one of the turbos. That’s insanity for that engine.
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To be fair, that's including ambient. So in reality he's more in the 28-29PSI range, which isn't really much out of line with what Audi does.
 
Tarheelpilot said:
I’m not following what you’re saying...
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The numbers he is talking about (43 psi) is including 1ATM. Normally automotive boost is measured/displayed without atmospheric pressure.

If you take 1 ATM our of his 43 PSI you're closer to 28 PSI, which isn't all that high for most Audi engines, especially the diesels.
 
jrcox19 said:
The numbers he is talking about (43 psi) is including 1ATM. Normally automotive boost is measured/displayed without atmospheric pressure.

If you take 1 ATM our of his 43 PSI you're closer to 28 PSI, which isn't all that high for most Audi engines, especially the diesels.
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Even if it is 43 psi gauge I personally don’t see what the big deal is. The question is, where does the manifold pressure really need to be to make the desired power? I bet this guy hasn’t determined that.
 
jrcox19 said:
The numbers he is talking about (43 psi) is including 1ATM. Normally automotive boost is measured/displayed without atmospheric pressure.

If you take 1 ATM our of his 43 PSI you're closer to 28 PSI, which isn't all that high for most Audi engines, especially the diesels.
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How does a pressure transducer on an intake manifold not measure the total pressure being delivered to the engine? Every turbo diesel I’ve had just measured the psi on the manifold downstream from the turbo and displayed it to me. Not sure how the transducer does any math to subtract anything... can you explain?
 
Tarheelpilot said:
How does a pressure transducer on an intake manifold not measure the total pressure being delivered to the engine? Every turbo diesel I’ve had just measured the psi on the manifold downstream from the turbo and displayed it to me. Not sure how the transducer does any math to subtract anything... can you explain?
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We live in a world of pressure. There is no such thing as vacuum, there is only less than ambient. Some gauges and transducers will start from an absence of pressure, so at ambient they will read 1 bar or 100 kPa. Those measurements are referred to as absolute.

Most people are accustomed to seeing gauges that read “0” at ambient pressure, which ignores the first bar or 100 kPa of pressure.

Every pressure transducer I’ve seen plugged into an engine controller measures in absolute but most people think in gauge.

Think about the manifold pressure gauge in many piston airplanes. With the engine off, it sits at 28-30ish inches. This is measuring absolute pressure.
 
mondtster said:
We live in a world of pressure. There is no such thing as vacuum, there is only less than ambient. Some gauges and transducers will start from an absence of pressure, so at ambient they will read 1 bar or 100 kPa. Those measurements are referred to as absolute.

Most people are accustomed to seeing gauges that read “0” at ambient pressure, which ignores the first bar or 100 kPa of pressure.

Every pressure transducer I’ve seen plugged into an engine controller measures in absolute but most people think in gauge.

Think about the manifold pressure gauge in many piston airplanes. With the engine off, it sits at 28-30ish inches. This is measuring absolute pressure.
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Now I get it thanks.
 
Tarheelpilot said:
Now I get it thanks.
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mondstster explained it much better than I did. This is definitely a case where airplane gauges (Manifold pressure) and automotive gauges (boost) don't display base on the same zero point. While I have no direct experience with this Audi motor, his boost target doesn't seem too high to me. Although there are much bigger problems with his engine plan than just boost, as others have pointed out.
 
Omalley1537 said:
He’s pushing at least 60psi worth of hot air out of his mouth, lol

He must be going for the illustrious combo of early-80’s Reno Unlimited reliability coupled with low performance...
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Skip forward to 13:00 in the latest video to miss most of the pointless blather, then the good stuff comes out, for example, his admission he didn't think placing the induction air aftercooler ahead of the radiator would cause the coolant temperature issues he's having. This is another acknowledgement that common sense didn't play a part in his decision making, much less math.

The temperature of the external air being passed through the aftercooler increases about 100° F at full power. Add to that the ambient air temperature, along with the temperature under the cowling, and the air passing through the radiator during ground and takeoff operations could easily be close to 200° F on a summer day.

It follows there should be no surprise engine coolant temperatures immediately increase upon application of moderate power levels and show no indication of leveling off.

In the video Muller also mentions he'll have "way less drag" with the main gear wheel wells covered. Such are the straws he is grasping at. Combined with his experiments with the wastegate springs, he now thinks after reducing power to 65%, he'll be able to climb to pattern altitude without frying the engine.

This is indeed incredible progress
 
jrcox19 said:
To be fair, that's including ambient. So in reality he's more in the 28-29PSI range, which isn't really much out of line with what Audi does.
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Shouldn't be too much of a stretch on just about any turbo diesel. My Ford 6.0 will hit 25-27psi on moderate acceleration getting up a highway on-ramp. I don't hardly ever floor it, but I'd bet 29psi is probably were it would end up but I don't feel like testing the ability of the intercooler/intake boots to remain in place. I don't want to be reattaching the boots on the side of a highway, lol.
 
I really don't see what the obsession with the manifold pressure here is. No matter how high he runs it, it is likely to be the least of the concerns.

Some of you guys need to get out more. Many bone stock turbo diesels will make 50ish psig manifold pressure. It's no big deal.
 
Peter’s latest video is entitled “One last check”. I hope it’s not prophetic, as he indicates his next video will be about the second flight......

I wish him well in his endeavor, but would hate to see harm come to him. Be safe sir.
 
painless said:
second flight
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I guess there was too much wind

BUT.. the man redeemed himself a little bit, he's installing an intercooler! I was worried he'd spend the time adding more tanks but he's talking about installing a naca vent in the nose and funneling that to an intercooler
 
Tantalum said:
I guess there was too much wind

BUT.. the man redeemed himself a little bit, he's installing an intercooler! I was worried he'd spend the time adding more tanks but he's talking about installing a naca vent in the nose and funneling that to an intercooler
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Too much wind ... was it gusting to 2 knots again?

ETA: Seriously, I haven’t found a place with less wind than Valdosta. When I first started flying, I was signed off to fly a J-3 Cub with a wind restriction that let me fly in conditions he is rejecting in the 2-ton Raptor, even if I had to use the wrong runway and take it as a direct crosswind.
 
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What is the point of flying it to the pattern at 65% power? Seriously? Is there any logical reason to waste time trying to do that? Nobody is going to fly the plane under those limitations. Flying it without resolving the heat issue isn't really moving anything forward, is it?
 
I haven't watched the whole video but perhaps he's trying to see if it will wobble less with the sheet metal duct taped to the bottom of the wing over the wheel wells
 
Tantalum said:
I haven't watched the whole video but perhaps he's trying to see if it will wobble less with the sheet metal duct taped to the bottom of the wing over the wheel wells
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But isn't that sort of like fixing the shimmy in the wagon wheel when the horse pulling it has a stone in the hoof?
 
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