השוואת שיטות

	הספק עודף סגולי	תורת אלמנט להב ותנע
תחום	תעופה וחלל	תעופה וחלל
משפחה	Process / pipeline	Process / pipeline
שנת המקור	1970s	1889
הוגה השיטה	John Boyd, U.S. Air Force	William Froude, Heinrich Glauert
סוג	Tactical metric	Analysis method
מקור מכונן	Boyd, J. R., & Hammond, J. A. (1971). The mechanics of air combat. Fighter Weapons Newsletter, US Air Force Tactical Air Command.	Froude, W. (1889). On the elementary relation between pitch, slip, and propulsive efficiency. Transactions of the Institution of Naval Architects, 30, 94–103.
כינויים	Ps, energy maneuverability theory, specific power	BEM theory, rotor performance prediction, actuator disk method
קשורות	3	3
תקציר	Specific excess power (Ps) is a metric that quantifies the rate of change of energy per unit weight, representing how quickly an aircraft can trade speed for altitude (or vice versa) at a given flight condition. Developed by John Boyd in the 1970s as part of energy maneuverability theory, Ps is essential for assessing aircraft performance during combat maneuvering, climb, and acceleration. Specific excess power is widely used in military aircraft design, flight envelope analysis, and tactical air combat assessment.	Blade element momentum theory (BEM) is a fundamental method for analyzing rotor performance by combining blade element aerodynamics with momentum conservation. Developed initially by Froude and refined by Glauert and Leishman, BEM decomposes a rotor into radial blade elements, computes local aerodynamic forces, and sums contributions to predict total thrust, torque, power, and efficiency. BEM is standard for helicopter, wind turbine, and propeller design.