How to properly design a VTOL/ADAV helicopter-plane?

[Christophe]

Shall we go Remundo?

Info: http://inter.action.free.fr/docs/02-avis-general.pdf

[Remundo]

Saint Yan, it's not far from my home, it's worth going there.

an exceptional reduction of 180 € is granted if the registration is done
during aeronautical gatherings (RSA, ULM Blois). She is still from
100 € if the registration reaches us before April 1, 2023 (and 50 € if it
arrives before May 1).

kézaco the RSA, ULM Blois?

probably this: https://www.rsafrance.com/index.php/age ... el-a-blois

[Christophe]

Yes, these salon discounts are weird...

I will contact Michel Kieffer again, he has been in the association for a long time...

[Remundo]

Lift, Drag and Wing Smoothness

Also, there is a tendency to lengthen the wing, to reduce the chord at the wing tip[/b], but also to install devices there to reduce these parasitic vortices such as fins / winglets.

Found on facebook, this concept that doesn't skimp on winglets

Atea_VTOL_ascendant_flight_technologies.png (332.91 KiB) Viewed 1743 times

Which in my opinion mixes the good and the less good.

I find that the layout of the wings is interesting, especially at the front where the "duck" fins are very developed to the point of forming almost a normal-sized wing.

The aerodynamics of the fuselage in airplane mode seem to be of good quality.

On the other hand, the installation of the propellers in the wings is harmful; this probably decreases lift in airplane mode in addition to generating turbulence/drag on the wings.

If you have money, here it collects by tens of millions €..., very proud of their aerodynamically questionable project at first glance.

[Christophe]

Not even made and already expired: there are double winglets

I find it hard to believe in the stability and performance of pierced wings...

21 Million, 245 promises of sale based on a prototype that never flew (at least not in the air…)…here is the start-up nation of big mouths that is banding… Macron…

[Christophe]

I found this Remundo in a professional equipment magazine, it's in your corner apparently: Fleasy X8ed in flight...virtual!

I didn't know that we could certify on the basis of scale models!!

X8ed.jpg (350.8 KiB) Viewed 1687 times

This allowed me to discover: https://hionos.com/ which looks interesting!

[Remundo]

yeah the shape of the wings inspires. They are looped, which reduces the marginal vortices at the tips of conventional wings.

This contraption on the other hand is a little strange, it is an "octocopter" whose wing seems to tilt.

But it is above all by its propulsion which in my opinion is a big pipe...

I quote "a turbocharged high temperature fuel cell"...

Not content with this gas plant, the designers added a tank of hydrogen... liquid, that is to say close to absolute zero...

I bow !

[Christophe]

Apparently it goes to the EASA!

[Remundo]

Lift, Drag and Wing Smoothness

The wings of an airplane (and even the blades of a helicopter) have the task of moving through the fluid creating the greatest lift and the minimum drag.

The smoothness of a profile is defined by Lift / Drag = Cz / Cx
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The shapes of wings and choice of profiles are very numerous, but for light and economical aviation, it is necessary to choose wings of high glide ratio.

Note that the data below are indicative as they depend on the Reynolds number

A US site: Airfoil Tools provides you with all the profiles and technical characteristics of this table.

I come back to you with a question.

I look for a wing with a flat (or almost flat) lower surface with a small Cx and a good Cz. Also called "plano-convex wing"

In English, these coefficients are respectively called Cd (Cdrag-drag) and Cl (Clift-lift).

On the American site "airfoil tools", I found this reference "Daytonwright6-il rather interesting.

Here is an image captured for the archive.

aile_intrados_plan.png (246.18 KiB) Viewed 837 times

the "alpha" parameter is the angle of inclination of the wing with respect to the horizontal.

Are flat-bottomed wings the subject of a site that lists them according to this criterion?

[Remundo]

Short video report from the ULM World Cup in Blois which was held from September 1st to 3rd in BLOIS

From 4 minutes 50sec, you will see Christophe helping a pilot to familiarize himself with his contra-rotating twin-rotor electric paramotor DRAGONGLY.