Variable Geometry Control Surfaces

[ToniT]

Regarding laminar air flow, how would one better provide laminar air flow AFTER the trailing edge of a wing. I propose that turbulent air after a wing produces a minor vacuum; though I don't have any such data (moving a leaf trapped in the vacuum of a paddle as the paddle is swept through the air).

 

As you can see in the below video, laminar air flow breaks up after the trailing edge of a wing. The air splitting at the leading edge DOES NOT meet up at the same time with the air at the trailing edge.

 

Cambridge scientist debunks flying myth

 

So could a pressurized plenum create a smooth transition of air flow at the bottom trailing edge of an airfoil, to provide laminar air flow after the passing of the wing?

 

The purposes being:

 

1) more aerodynamic wing; lift with less drag

 

2) quieter wing, potentially applying to propeller design

 

3) an alternate form of propulsion (already been done in youtube videos)

 

4) with a sensor array, a dynamic way of controlling aircraft wing flutter

 

5) to neutralize vibrations and heaving from thermals to provide a more pleasant passenger experience

 

Are pressurized slots in the top of the wing needed, if the laminar flow is constant and turbulence is neutralized after the trailing edge of the wing?

 

The power needed reduced by creating a bump just before the pressurized plenum, so that a much smaller volume of air is needed to match the velocity of the upper wing trailing edge air flow.

 

Or even eliminating the trailing edge, by providing a pressurized plenum as the trailing edge.

 

 

[bexrbetter]

True, but then birds don't cruise at .8 mach either.

Obviously you have never come across Melbourne Magpies.

 

Gee, Nev, you need to catch up with Duan Phillips, the Phillips helicopter designer.He's 20 years in front of you, and he only needs a few thousand dollars more, to get airborne!

Wow, he's been at it since before 1972!

 

Popular Mechanics

 

Con-your-dough-a effect UFO's have flown before.

 

 

 

 

[facthunter]

Relating to the video and explanation. The air particles having to reunite at the trailing edge was always a BS proposition. It's easily disproven as is shown with the smoke in the wind tunnel.

 

Also Bernoulli is hard to understand for most people. (Static plus Dynamic pressure is a constant.)

 

Air is a gas having density and viscosity. Density is proportional to lift achieved.

 

Newtons laws of MOTION simplified. Something stays still or travelling in a straight line unless another force changes that situation which will then produce an equal and opposite reaction. That reaction when a wing produces it is called LIFT. ie A certain mass of air has been moved from where it was to somewhere else by the passage of the wing through it in a certain time. That uses energy. You are either gliding (using potential energy) or you have a power plant but you get the force you need to stay in the air, as a result of you wing working on the air it is passing through.

 

The only way to move a gas (accelerate it or make it describe a curve) is to have a lower pressure in the direction you want it to accelerate towards. This happens on a large scale with wind systems shown on met charts by the isobars. NO wind gradient NO wind. Nev

 

 

[ToniT]

Nev, agree broadly, but I'm thinking of a turbo prop helio-courier. In a demonstration, the plane took off from a runway and entered a climb that traced back on the ground over its point of take off and then landed back on the same runway it took off from.

 

The relative wind and high angle of attack provided a lift vector up and backwards.

 

I'm thinking an actual/virtual pressurized air plenum could change the shape of an already safe fast wing, provide laminar slots and burble cancellation at high speed (slipping through the air with less drag), and leading edge thickening at slow speed (providing STOL performance).

 

By itself, a single rotating cylinder makes a poor leading edge for a high speed air foil; it's a cylinder and not aerodynamic. But what about a slotted leading edge. Not just providing for laminar air flow, but also a virtual air plenum to dynamically change the effect of the relative wind over the wing; i.e. changing NACA air foil shapes.

 

By having zones of independent pressure control of the laminar flow slots, this provides a safe variable geometry air foil. If the system fails OFF, the plane reverts to a high speed air foil. If a zone loses pressure control, shut it off and revert to a high speed air foil.

 

All flight has risks, and engineering a high reliability blower and pressure control seems plausible.

 

The highest risks occurring during takeoff and landing transitions; when STOL performance is wanted.

 

 

[facthunter]

The design doesn't need a separate engine. Higher pressure air can be controlled to augment lift by boundary layer control and rearward HP flow gives thrust. The control would be by louvres and/or valving and engine power. Thanks for replying. Nev

 

 

[ToniT]

Declassified Reports related to Boundary Layer Propulsion

 

In all developments vacuum/suction was used

 

FLIGHT TEST EVALUATION OF A DISTRIBUTED SUCTION HIGH-LIFT BOUNDARY LAYER CONTROL SYSTEM ON A MODIFIED L-19 LIAISON AIRCRAFT

 

US NAVY Aviation Materials 1966 (declassified)

 

http://www.dtic.mil/dtic/tr/fulltext/u2/635953.pdf

 

APPLICATIONS OF HIGH EFFICIENCY BOUNDARY LAYER CONTROL

 

OFFICE OF NAVAL RESEARCH (declassified)

 

http://www.dtic.mil/dtic/tr/fulltext/u2/135753.pdf

 

Public Domain

 

NASA jet engine used to propel aircraft by sucking intake from boundary layer

 

NASA Runs First-Ever Test of New Jet Engine Tech

 

The Jet Airplane Using Boundary Layer Air for Propulsion

 

Douglas Aircraft Company

 

http s://arc.aiaa.org/doi/abs/10.2514/8.1273?journalCode=jans

 

 

[facthunter]

Thanks for that. In the interests of simplicity I'm not using suction but a pressurised plenum and ducting that is part of the structure with ports that assist boundary layer control and provide propulsion from controlled and suitably orientated exits. This eliminates an exposed propeller (safety), enables engine heat and exhaust to contribute to thrust . Allows the engine to be mounted more centrally Lowers undercarriage height etc .Nev

 

 

[ToniT]

...a pressurised plenum and ducting that is part of the structure with ports that assist boundary layer control and provide propulsion from controlled and suitably orientated exits .Nev

I look forward to your developments. I wonder if an RC mock-up would reduce the cost and iteration time involving implementing your concepts. Also, a related YouTube video could potentially support a Kickstarter fund raising campaign to built a full size prototype.

 

...

 

Plus I think seeing your concepts in a video would be .. Cool as H_LL !!!

 

 

[facthunter]

I'd like someone with facilities to take it up. There's no doubt it will work. I' a bit concerned with the efficiency, but otherwise ..... Nev

 

 

[ToniT]

Sometimes, performance capability with specific characteristics outweighs the priority for efficiency based on a specific or class type of mission. I think for your concepts, maybe don't restrict your development strictly to energy efficiency and consider other potential performance benefits. Even Gyroplane Jump Takeoff, is not energy efficient as compared to runway takeoff. But it serves a function when there is no runway. VTOL as far as I know is never energy efficient, but it serves a purpose that outweighs the interest in energy efficiency.

 

Thinking outside the box on the wild side, your concept could potentially be applied with a computer to provide a flat spin with lift, to act as an emergency measure to arrest a fall like a ballistic parachute without the parachute. An airliner instead of doing an emergency landing along a long stretch of obstacles, might land vertically at an acceptable sink rate. This is just an example of thinking of how energy efficiency is of lesser importance than the applied mission.

 

Maybe make a long and wild list of missions that you think your concepts might apply to, and add to it every few days (the brain needs 3 days to correlate 75% of what we previously considered). Then after a while, see if anything jumps out at you and/or your associates as a direction to apply efforts.

 

Something about "Moments of Inspiration" (genius). Everyone has moments of inspiration many times every day. However, they only last about 3 seconds and then they are forgotten. Keep a pocket notepad and pencil with you every moment of every day. When your brain correlates momentarily vast relationships to provide you with an inspiration, write it down as fast as you can in detail. This will help you remember the details of your inspiration so you can come back to it later. If you do not capture your moment of inspiration, it is gone forever; until someone else has a similar inspiration to explore. For the Moments of Inspiration you do not plan to develop, create a blog and write them down for humanity to explore. These become part of other people's inspirations and you become part of progress.

 

 

[ToniT]

To get a following of people interested in your inspirations, Google provides a good free blog site at

 

blogspot.com

 

or otherwise known as

 

Blogger.com - Create a unique and beautiful blog. It’s easy and free.

 

I recommend creating a page of links to your posts. Where the links are organized into a Table of Contents; with Headings like Aerodynamics, Aircraft Missions, Music Melodies, Physics, ... whatever categories interest you. That way you can blog about random topics, and yet visitors and yourself, can easily find groups of articles that interest them.

 

Over 40,000 people visited my pages, until I took my blog down because I professionally was looking for an opportunity, and I didn't want my often non-mainstream views from blocking access to the opportunity I was seeking.

 

I suggest creating your blog under a fictitious name so your published views do not effect your access to professional opportunities.

 

Google provides reports of how many people (anonymous) visit each post, and where they are from geographically.

 

 

[facthunter]

Thanks ToniT, I don't want a radical plane to change the world, and I usually get more results from Perspiration than Inspiration and have had this project in mind for at least 20 years. It has to be cheap, safe, and work in, a practical sense for the sort of plane WE could build and fly. The forum thread title is misleading in regard to what I have in mind. Thanks for your contribution but I'm flat out otherwise as well and can't commit to the effort required to do a blog properly. I already spend too much time on line. Nev