Ad
related to: how to calculate aircraft performance comparison
Search results
Results From The WOW.Com Content Network
Energy–maneuverability theory is a model of aircraft performance. It was developed by Col. John Boyd, a fighter pilot, and Thomas P. Christie, a mathematician with the United States Air Force, [1] and is useful in describing an aircraft's performance as the total of kinetic and potential energies or aircraft specific energy.
The thrust-to-weight ratio and lift-to-drag ratio are the two most important parameters in determining the performance of an aircraft. The thrust-to-weight ratio varies continually during a flight. Thrust varies with throttle setting, airspeed , altitude , air temperature, etc. Weight varies with fuel burn and payload changes.
SFC varies with throttle setting, altitude, climate. For jet engines, air flight speed is an important factor too. Air flight speed counteracts the jet's exhaust speed. (In an artificial and extreme case with the aircraft flying exactly at the exhaust speed, one can easily imagine why the jet's net thrust should be near zero.)
Aircraft performance refers to the ability of airplanes and helicopters to accomplish certain useful things. [1] It is an important consideration when designing and testing aircraft, to ensure the aircraft can be operated in an efficient and economic manner. [ 2 ]
Aircraft engine performance refers to factors including thrust or shaft power for fuel consumed, weight, cost, outside dimensions and life. It includes meeting regulated environmental limits which apply to emissions of noise and chemical pollutants, and regulated safety aspects which require a design that can safely tolerate environmental hazards such as birds, rain, hail and icing conditions.
As noted earlier, , =,. The total drag coefficient can be estimated as: = [()], where is the propulsive efficiency, P is engine power in horsepower, sea-level air density in slugs/cubic foot, is the atmospheric density ratio for an altitude other than sea level, S is the aircraft's wing area in square feet, and V is the aircraft's speed in miles per hour.
The type of jet engine used to explain the conversion of fuel into thrust is the ramjet.It is simpler than the turbojet which is, in turn, simpler than the turbofan.It is valid to use the ramjet example because the ramjet, turbojet and turbofan core all use the same principle to produce thrust which is to accelerate the air passing through them.
The payload fraction of modern twin-aisle aircraft is 18.4% to 20.8% of their maximum take-off weight, while single-aisle airliners are between 24.9% and 27.7%. An aircraft weight can be reduced with light-weight materials such as titanium, carbon fiber and other composite plastics if the expense can be recouped over the aircraft's lifetime.