Powered aircraft must produce forward "thrust" to overcome rearward "drag" and then also be able to accelerate forward. The forward thrust also enables aerodynamic lift to occur, which balances the weight of the aircraft. Much of the drag that exists that is associated with airfoils (wings) is due to turbulence that develops along the top of airfoil and behind the airfoil surface. Until now, very sleek airfoil shapes and relatively narrow wings have been the standard ways of trying to minimize this turbulence effect. However, these sleek shapes also necessarily have less Bernoulli lift effect, for standard physics and aerodynamic reasons.
An entirely new and different approach is presented here.
Find some book or some wind tunnel movies to carefully look at that turbulence that is above an airfoil. It is very well established that it is NOT random turbulence! (That's IMPORTANT!) It begins above the upper surface of the airfoil, and it has a very periodic (but unpredictable) motion, a pattern, it is NOT random.
These eddies or whorls are essentially miniature horizontal hurricanes! A technique is presented in another web-page, ( Eliminating hurricanes http://mb-soft.info/public4/hurrican.html ) that uses an aspect of the physics concept of forced vibration or forced resonance to try to destabilize and disrupt hurricanes. That basic principle can be used in this application.
From the reference system of the wing structure, air in front of the airfoil approaches the front (leading) edge, where it is split apart into two separate flows, one above the airfoil and one below it. The upper path is the one on which we will concentrate here, although this same system could be applied to the under surfaces of the airfoil as well.
It has been well known for more than 50 years that the airflow begins as what is called laminar flow, a very smooth and orderly motion of the air past the airfoil. At some distance along the width (chord) of the airfoil, small turbulences start to develop, in what is called a transition zone. Soon after, all laminar flow is gone, and the third stage of the airflow is called turbulent flow
In practical aircraft, laminar flow rarely continues beyond 1/4 of the wing chord, and before the halfway point, fully turbulent flow exists. We will look carefully at each of the three phases in conventional airfoil design.:
In considering the new deck of cards example, one can see why laminar flow allows extremely easy and free passage of the fluid (air) to go past with extremely low friction (drag).
There are some characteristics of air which affect just how smoothly
the air can go by an airfoil, particularly the density of the air
and the dynamic viscosity of the air. The velocity of the air is
also very important, as is the length of time (distance) that the
air is moving along that boundary layer. There is a defined number,
called the Reynold's number which is generally used in calculations.
If we consider an airliner wing at 30,000 feet altitude, the temperature
is very cold and the air pressure is rather low, but the density and
dynamic viscosity are both well known, and the Reynold's number is given
by:
Re = 4100 * V(mph) * L(feet).
For an airliner flying at 500 mph, by the time that the air has gone (L = 1) one foot along the airfoil surface, the Reynold's number is already 4100 * 500 * 1 or around 2,000,000. One of the key usefulnesses of the reynond's number is in determining whether laminar or turbulent flow exists. A common guideline is that if the Reynold's number is above about 500,000, laminar flow ceases. Therefore, we would be considering a situation where laminar flow had already disappeared and fully turbulent flow was acting. This situation would then apply for the remaining 12 feet of wing width, where fully turbulent flow exists.
If the top surface of the rear of the wing is divided into thousands of small panels, and each were "vibrated" vertically at a specific frequencies, the same disruptive effects would occur to those eddies and vortices. Now, if those turbulent eddies would disappear (or never appear in the first place), the wing would have very little drag!
This, too, is currently existent technology. Big astronomical telescopes now have such mechanisms that "flex" the mirror in REALLY fast response to a computer, to make corrections for atmospheric turbulence, and make clear images where none were before possible. In an optical way, they are "eliminating" the turbulence in the atmosphere. This aircraft system would have similar actuators in hundreds of locations around the rear top surface of the wing. A computer would "flex" the surface of the wing up or down (a fraction of an inch) (rather rapidly in this case) and that slight movement would disrupt the eddies right above it.
If "laminar" flow can therefore be made possible, the improvement would be staggering, like a drag of 1/10 of present aerodynamic drags! But, even if that is not possible, I am confident that the reduction of turbulence would greatly improve drag and allow far more fuel efficiency for all airplanes.
The necessary mechanisms are also very mundane items, relatively standard PC computers and slightly modified microphones and loudspeakers! There are some proprietary aspects of this system, but they are all long-known and fully=proven, too!
( http://mb-soft.info/public4/othersci.html )
C Johnson, BA Physics, Univ of Chicago