Bob Hoover would love this man and this project. Ya'll get back to barking about how you should never turn into a dead engine on a twin now. Hehe.

I find this incredibly hard to believe! While I could understand a maritime engineer not understanding when to use TAS vs IAS, there is no way an even remotely competent maritime engineer would not have a better understanding of how a prop works! While a layman might consider air and water to be very different, to aerospace engineers and maritime engineers (naval architects) they are they same, a fluid (air becomes a compressible fluid as you approach the speed of sound, but it is still a fluid). We all took the same fluid dynamics classes so I know what you SHOULD know.

Anyone with the background you claim would have answered Ted's question about prop exit flow velocity over the fueselage in a tractor aircraft in terms of Mdot and Delta V and would have known intuitively that as a vessel's velocity increases, the change in velocity of the fluid flowing through the prop decreases. They also would have known intuitively that for an aircraft flying at 300 knots the delta V and therefore the change in drag verses a pusher design would not be as significant as you proposed.

You are capapble of posting terms phrases and facts, but you clearly have no understanding of the concepts behind them. I would be shocked if you had a real engineering degree that involves any study of fluid dynamics and propellers. If you do, hire a lawyer and sue the school for a full refund of your tuition! Seriously!

[quote="Chris ]

Guess my humor "just" a mass balance equation slipped by you.

What are the basic units of Mdot and DeltaV? Read what I wrote again. But this time actually understanding what Mdot and DeltaV really means.

Let me break it down for ya since it was too complicated the first time...

From my quote above...

How much drag do you have in lbs. <--- Explanatory I hope.
You need an equal amount of thrust to match it. <---- Again.. Self explanatory I hope.
So weight of air times volume of air gives velocity. <---- Mdot to match thrust needed Yes?
Add that to ship speed. <------DeltaV Yes?

Sorry for breaking down in terms folks could more easily understand. But more importantly breaking it down so "educated" folks can't abstract a little education into a argument that sounds good but makes NO sense when you dig into it from a first principles basis which is exactly what I was doing.

Go back and see how that particular thread ended and ask yourself who was right?

Good God there's lots of folks here that have been "educated" but don't really know what the hell they are saying.

And your assertion I don't understand the difference between TAS and IAS is gonna need a little more proof as well. Specifically the implications of which speeds are affected by mass and which is not and why, and specifically again why that matters in regards to, wait for it, the shape and slope of polars NOT being affected by mass.

I wrote a piece on it that a former F-16 driver and commercial airline captain (among a few others) upvoted... so MAYBE I know what I am talking about.[/quote]
Post the article.

Chris, after I posted not only the correct formula, but also and explanation and actual numbers, you were able to google it and figure out something you should have already known? Wow, google showed you how to get from a high school Newtonian physics to a simplified thrust equation so you could paste it here. Color me incredibly unimpressed.

BTW, Ted asked a question. You provided a condescending “it is simple” with a formula that while not incorrect, was not directly applicable, and of course no actual answer to the question. It is a pattern repeated throughout this thread since you showed up. You have not been able to directly answer any question, other than the ones you ask yourself. You thrive on misdirection, straw man arguments, and avoidance while simultaneously attacking anyone who disagrees with you. If you think that is earning you anyone’s respect, you are only fooling yourself.

Do you know what you are talking about? Clearly you know some things here and there, but it is even more clear that you genuinely lack any understanding. It also seems you are not who or what you claim.

I originally thought you were a misguided fan who was overly emotionally invested in the Raptor. Now I think you are simply a fraud, here for no other purpose than to kick up some dust for your personal entertainment. And because of that, I am out!

I am going to disagree with that assertion and characterization of events Matt. There are lots of folks here with varying levels of education and understanding and I have taken each individual issue and broken it down from simple Newtonian psychics with common sense and simple to understand explanations and then when the "educated" folks came in started throwing around big words, I posted handwritten integrals and derivations that are used to explain the point rate acceleration of fluid (in all three axis) across an airfoil for any given Reynolds number, which is used to build advanced fluid dynamics simulations you need a super computer to run.

Some folks here claim I don't know a damn thing. Others have claimed my answers are TOO precise and correct and quick so I must be a ringer brought in by the Raptor team.

Which is it? Can't be both right? Maybe it is just like I said it was...

I am interested in the project and have been watching this thread and the videos online for a year.

I've run nuclear reactors, worked in the maritime/offshore and onshore oil patch, and have designed and sold some propriety oil separation and and water cleaning equipment I designed and brought to market. As well as writing software for companies like Compaq, Halliburton and Sikorsky. My dad flew military and private. So have been around aviation since I needed two phone-books and a boat cushion to see over the hood. I built and raced RC planes and pylon racers when I was kid. I started flying hang gliders when I was 17 and competition (sailplanes as well) for about ten years. So have been around aviation for a while given I am 49 years old.

I came here hoping to air out what I though were my biggest concerns for the project (nearly none of which have been identified here) and got caught up in a bunch of ankle biting naysayers who got their shorts in a twist when it has been proven time after time (using common sense to advanced math as each case required) they don't know quite as much as they though they did.

Folks laughing about polar is a prime example. Go back and look at the folks that have up-voted my posts (especially the technical ones) and see if you can identify the common thread among them. I can.

Like I said.. it is all gonna be over except the crying pretty soon. Everyone take a good look around at the naysayers. Mike won't quit till he is dead, which some here will joke about. He has a hell of a lot more guts and grit then 99% percent of us and ALL off folks spewing BS. And I happen to think he is dead on the money with his approach to solving the problems he set out to solve. And I have more than adequate proven my technical chops here in aerodynamics and engine knowledge to make you think twice before you discount my opinion.

You can toss around all the technical terms you want to given your education Matt. It is just air... moving air. I don't think you like it when folks demystify what you studied so long to learn. And I think you really don't like it when someone takes you to the mat and proves from a first principles perspective you don't know what you are talking about. And the backs it up with deep understanding of the calculus involved. And walks you through step by step.

I am beginning to believe flying with polar bears is dangerous

Only the non aerodynamic ones

For one thing, it is possible to have a conventional design (main wing up front) that generates positive lift on the tail over a small CG range (IIRC the Bonanzas fit this description). Some other factors in the canard vs conventional layout include changes in airflow over the rear wing caused by the canard, and the added complexity of lift enhancing devices needed to overcome the inherently higher landing speeds.

One of the biggest challenges in aircraft design is that virtually every potential performance improvement comes with some adverse consequences that all too often more than cancel the expected improvement. Another is the well known fact that real world performance never comes close to the theoretical maximums.

BTW, I have a couple questions WRT the Raptor's engine and associated performance:

1) Even if (by some miracle) the Audi engine plus belt drive can deliver a reliable 300 HP to the prop and the drag is so small that 300 HP can actually deliver 300 Kt, will the engine actually be able to CRUISE at 300 HP? Using the common max cruise power to full rated power ratio of .75 that would mean a 400 HP engine.

2) Doesn't the Lancair IV get a significant portion of it's drag reduction compared to other airplanes from close attention to the area rule. I don't see that in the Raptor, am I missing something?

Man, I just hate it's going to be December before the test pilot gets to come out to review everything. 2 months of Chris telling everyone how dumb they are and how polar everything is.

I do see he has ventured over to the homebuilt page to defend the raptor. There's a few guys in that thread that are going to be more than happy to take him to task.

"homebuilt page"?

Where's that?

I like how he assumes because many of us think the raptor will fall short and not be a super success - he assumes we’re anti-experimental.

Right....

We’re not supposed to use the T word, but this is the most successful one in the history of BT.

homebuiltairplanes.com

Disabusing myself of the idea folks can't refuse to believe their lying eyes. Again.

Lots of folks over there convinced there is a ton of slop in the control linkage between the control horn on the aileron's and stick in the cockpit given the spade is "bouncing up and down freely" during high sped taxi.

Pointed out the run way is rough as hell, and you can actually see the hood bouncing/right stick moving in the cockpit so the ailerons are indeed tightly coupled to it. Hilarity of other "explanations" ensue.

It's at least comforting, I suppose, to know the "disease" is not localized in one locale.

Ego being the anesthesia that deadens the pain of stupidity is not a localized phenomena. Rest easy folks.

Delenda Carthago!