Interesting new plane: Celera 500L

[Logic]

Hmmm... Not the epitome of efficiency as they want you to believe.
More built for looks:

Aircraft (wing) with inherent stability: Dihedral, swept back wing.
That's what they have done here.

Aircraft (wing) with efficiency: Anhedral, forward swept wing.

If you want to get away with some anhedral angle and keep stability, you can go with a high wing as the Russian Elusion's have done.
But then where to put your landing gear?
These guys have made the wing so low that they've buggered up the laminar flow on the underside of the fuselage!

Except for that low wing to fuselage, it's amazing how stretching or thinning the fuselage a bit has improved it's looks.
The swept back wing also looks faster adding to the looks.

The engines in the stock Buz Jet style also does nothing for laminar flow and it's rebounding air 'squeezing' the fuselage forward effect.

So ye; They too have moved from efficiency to 'Looks!' to sell what is now almost 'just another run of the mill' aeroplane.

[freebeard]

For looks and efficiency -- the gull wing.

[Piotrsko]

Adding pylons makes more drag. You know that.

Engine intake is one of those cant win drag issues especially if you also need ccoling air.

[Logic]

Originally Posted by Piotrsko

Engine intake is one of those cant win drag issues especially if you also need ccoling air.

No it's not!

The Meredith effect is a phenomenon whereby the aerodynamic drag produced by a cooling radiator may be offset by careful design of the cooling duct such that useful thrust is produced by the expansion of the hot air in the duct...
https://en.wikipedia.org/wiki/Meredith_effect

...due to the Meredith effect, it has been possible
not only to eliminate the radiator drag, but also to increase the
total thrust of the system of about 2400 N at cruise speed.
https://www.researchgate.net/publica...eredith_effect

The P51 Mustang

https://www.supercoolprops.com/home/...h_effect2.html

You might also be interested in Porsche etc's graphs in this video and NB the similarity in duct shape:

http://www.youtube.com/watch?v=doP04J05QdQ

NB that car speeds are too low to get actual thrust, but the drag reducing effect is there.

Lastly; consider the paper below, where basically a 'bit too long' car belly-pan is dropped away from the car underside at it's rear, making a crude Meredith Effect cowl of the whole engine bay, decreasing the Cd of the vehicle.
(I'd make it hinged/adjustable and spring loaded. And round the top edge.)
https://ecomodder.com/forum/showthre...ard-41539.html

Naturally; all this will 'spontaneously disassemble' as it's Me who said it!

[freebeard]

Engine intake is one of those cant win drag issues especially if you also need ccoling air.

Interesting question should the intake area be subtracted from the frontal area or multiplied by the internal drag?

Cooling ram air is one case, but with a turbojet the intake is sucking on the ambient pressure.

[Logic]

Originally Posted by freebeard

Interesting question should the intake area be subtracted from the frontal area or multiplied by the internal drag?

Cooling ram air is one case, but with a turbojet the intake is sucking on the ambient pressure.

Good question!

In a stationary turbine (as is the case wit h a hovering drone);
The the air directly in front of the compressor blades/intake is being sucked toward the intake and thus the intake/engine sucked towards it in the opposite direction.
Then air not directly in front also being sucked into a stationary turbine causes a vacuum on the bell mouth surface.
So definitely subtracted here.

This cutaway animation is confusing in that the bell mouth half is 'transparent', but it gives you the idea.

https://www.youtube.com/watch?v=jFwo_3IxZyo

Now if the drone starts rising; still a negative.
But as the drone starts rising faster and faster; does it reach a point where it cannot imbibe that air fast enough and the number goes from a negative to a positive, with the thrust provided solely by hot jet squirting out the back?

When you NB that there are people trying to make variable diameter bell mouths it seems that a point is reached where the larger diameter of the bell mouth is trying to shovel in more air than the compressor can suck.
https://www.youtube.com/watch?app=desktop&v=orLjrswcpxI

Then when you head into high subsonic there's divergent ducting, similar to that used for the Meredith Effect and radiator ducts, slowing the air and increasing static pressure ahead of the compressor turbine.

(At a guess the Meredith Effect is likely considered in the (CFD) design of the combustor nowadays..?)

So yes at some speed the frontal area of the turbine does seem to go from being a negative to a slight? positive in CdA maths.
What that speed is; I don't know.. yet! And it will all get nuts at supersonic speeds with convergent-divergent ducts to slow the air down to subsonic.

Lets see... Well this over-complicates the answer and I wont be swatting it all up now!
https://core.ac.uk/download/pdf/188364971.pdf

[Piotrsko]

Drag is drag. don't matter what makes it, it's subtracted from total thrust.

[Logic]

Originally Posted by Piotrsko

Drag is drag. don't matter what makes it, it's subtracted from total thrust.

"Drag is drag" is not in contention here.

HowTF can you be equipped to answer a question if you don't know whatTF it is!?
If you aren't going to read the posts/questions with the intent to comprehend and understand them; why bother 'reading' in the first place? never mind replying..!

The question is:
Where the air is actually being sucked into a high bypass turbine or EDF rather than hitting a 'static' surface, what is the CdA of that turbine and how do the aero guys do the CdA maths of turbines? Especially as airspeed increases.

I'm afraid I cant summerise or dumb down the question further for you, but do feel free to ask if you are still having comprehension issues.

[freebeard]

The question is:

Thank you for your understanding.

"Somewhat crazed 1826 miles WSW of Normal"

Can't say you weren't warned. WSW is a tell. The costant sunshine gets to them.

[Piotrsko]

It's what google says my location is in respect to Normal Indiana. No meaningful relationship to anything else intentional or otherwise.

Somewhat crazed is my reply to Caveat emptor.

How is it that one's formun handle is actually meaningful or even relevant?

freebeard, or Logic. Hmmm not a lot of truthful significance in this.