After 1996, ECN maintained and improved the tool.) and the results are compared with experimental data, results from commercial CFD methods like ANSYS CFX and other methods like DTU-AED EllipSys2D and CENER WMB. The improved formulation is implemented in the most recent version of XFOIL and RFOIL (an aerodynamic design and analysis method based on XFOIL, developed by a consortium of ECN, NLR and TU Delft after ECN acquired the XFOIL code. The derivation of drag correction is based on the difference between the actual momentum loss thickness based on free stream velocity and the one based on the velocity at the edge of the boundary layer. The improved drag formulation predicts the drag accurately for airfoils with reasonably small trailing edge thickness. Drag under-prediction in XFOIL like viscous-inviscid interaction methods can be quite significant for thick airfoils used in wind turbine applications (up to 30% as seen in the present study). With plenty of power available, that is not a problem, but it causes much more consumption of jet fuel.Īn improved formulation of drag estimation for thick airfoils is presented. Unfortunately, that type of lift creates even more drag due to massive turbulence behind and above the wing surface. Massive amounts of air is given a downward Momentum, which again according to Newton, necessarily creates an upward Momentum to the wing structures. This is simple Newtonian action-and-reaction. This type of lift is entirely due to the wing surface being tilted, so that oncoming air is deflected down by impact against the bottom of the wing. It is the reliance on a second manner of lift, "reaction lift". However, these sleek shapes also necessarily have less Bernoulli lift effect, due to standard physics and aerodynamic reasons.Īnother trend in modern aviation is due to the enormous power now available in aircraft engines. Until now, very sleek airfoil shapes and relatively thin wings have been the standard ways of trying to minimize this turbulence effect. In many situations regarding Bernoulli Lift, around 6/7 of the total drag is due to this turbulence, with only 1/7 actually being unavoidable. 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. The forward thrust also enables aerodynamic lift to occur, which balances the weight of the aircraft. Powered aircraft must produce forward "thrust" to overcome rearward "drag" and then also be able to accelerate forward. The result would be extremely efficient flight, using far less than half as much aviation fuel to accomplish the same performance, and possibly less than one-fourth as much fuel consumption, without otherwise changing performance. There appears to be a method, TURCAN, to meta-stably eliminate most of that turbulence, and therefore most of the drag which must be overcome. This fact is closely related to the fact that virtually all aircraft are designed to use BOTH of two very different methods of creating Lift, called Bernoulli Lift and Reaction Lift, and the Reaction Lift is notoriously bad regarding creating massive turbulence and loss. Interesting, since they never showed any interest in THIS TURCAN technology which would CERTAINLY improve efficiency by 50% and probably 100% or more!įor the hundred years of powered flight, it has always been accepted that very large amounts of drag from air turbulence was unavoidable. Instead of an airline having to buy $120,000 of jet fuel for a specific trip, maybe only $60,000 would need to be bought! Then, with the gross airframe weight being 150,000 pounds less at takeoff (due to not needing to load those thousands of extra gallons of Jet Fuel) the overall efficiency would be even greater than that!īelow, reference is made to the US government spending millions of dollars to try to improve overall efficiency by 1.5%, several years ago. More practically, this new TURCAN technology should be able to reduce total aircraft drag to about half of current levels. Theoretically, total aerodynamic drag might be reduced to 1/7 current drag factors, meaning that fuel would then last around 7 times as long or as far! An aircraft flying at 500 mph has around 400 times more aerodynamic (drag) energy losses than if the same size-and-shape glider was flying at 25 mph.Īn Active Skin technology has been invented, TURCAN, where the vast majority of turbulence is eliminated. Gliders are only excepted because they fly so slow that better airflow patterns exist, where less turbulence occurs, and that the effects of turbulence regarding energy goes as the second power of airspeed. Repetitive MetaStable Cancellation of Turbulenceįlow in large Pipelines can also be improvedĪll aircraft except gliders have enormous turbulence losses during flight. Greatly Reduced Turbulence and Drag of Aircraft
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