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Flight Theory Paper
Abstract A relatively simple but comprehensive description of flight in terms of a volume integral of air's density-average acceleration around an aircraft is able to overcome misleading over-simplifications of explanations based on Bernoulli's equation and momentum theory. Applications of the equation indicate that the historic absence of such a valued insight has resulted in a series of engineering design paradigms with significant implications on aircraft fuel economy and capabilities. |
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What is that paradigm that has held back our airline industry? Modern aircraft have substantially missed the opportunity to use the fuselage as a lift-generating body. When using the fuselage to generate lift, fuel economy can double ... and much more ... details in below pdf file.
When deviating from airfoils for generating lift, a more accurate and "predictive" Theory of Efficient Flight is needed. That theory is comprised of a theorem, a constraint, and 2nd Law guidelines:
Theorem - Aerodynamic lift is created by the net downward bending/acceleration of air in the space around a flying object. The magnitude of lift is the net sum of [downward acceleration]X[air mass] as based on Newton's second law
Constraint - Analytical geometry dictates that the pressures created by the downward acceleration of air must be transferred to the object on substantially flat surfaces at surface angles of attack of about 0-4 degrees to attain a high lift with low drag.
2nd Law Guidelines - Once formed, regions of lower and higher pressure should be directed over relatively flat surfaces and preserved by various methods (e.g. winglets) as specific to the application.
When deviating from airfoils for generating lift, a more accurate and "predictive" Theory of Efficient Flight is needed. That theory is comprised of a theorem, a constraint, and 2nd Law guidelines:
Theorem - Aerodynamic lift is created by the net downward bending/acceleration of air in the space around a flying object. The magnitude of lift is the net sum of [downward acceleration]X[air mass] as based on Newton's second law
Constraint - Analytical geometry dictates that the pressures created by the downward acceleration of air must be transferred to the object on substantially flat surfaces at surface angles of attack of about 0-4 degrees to attain a high lift with low drag.
2nd Law Guidelines - Once formed, regions of lower and higher pressure should be directed over relatively flat surfaces and preserved by various methods (e.g. winglets) as specific to the application.
Conclusions
An approach of applying a volume integral to air's acceleration around an aircraft yields two inherently meaningful results of: 1) during equilibrium flight the net downward "ma" (mass times acceleration) of air is equal to the gravitational force acting on the aircraft and 2) insightful interpretations of lift can be attained by inspection of airfoil surfaces and the manner in which those surface force air upward versus downward.
This work advocates the replace of paradigms with new approaches as follows:
A pdf of the complete paper is available to right/below.
Conclusions
An approach of applying a volume integral to air's acceleration around an aircraft yields two inherently meaningful results of: 1) during equilibrium flight the net downward "ma" (mass times acceleration) of air is equal to the gravitational force acting on the aircraft and 2) insightful interpretations of lift can be attained by inspection of airfoil surfaces and the manner in which those surface force air upward versus downward.
This work advocates the replace of paradigms with new approaches as follows:
- The paradigm that increased air velocity (with resulting lower pressure) above wings is what causes lift should be replaced with the recognition that lift is created by the manner in which air foils cause downward acceleration of air.
- The paradigm that large wing aspect ratios are needed for high L/D ratios should be replaced with the heuristic that walls (e.g. wider wings, winglets) increase lift by strategically preserving pockets of high/low pressure air.
- The paradigm that a wing's surface area and respective lift coefficient are the best way to characterize lift should be replaced with a lift efficiency based on longitudinal cross-sectional area.
A pdf of the complete paper is available to right/below.
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This paper is under peer review for publication. When accepted for publication, the attached pdf will be replaced with a reference to that publication.
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