השוואת שיטות

	תורת אלמנט להב ותנע	משקל ואיזון
תחום	תעופה וחלל	תעופה וחלל
משפחה	Process / pipeline	Process / pipeline
שנת המקור	1889	1940s
הוגה השיטה	William Froude, Heinrich Glauert	Aviation engineering
סוג	Analysis method	Analysis method
מקור מכונן	Froude, W. (1889). On the elementary relation between pitch, slip, and propulsive efficiency. Transactions of the Institution of Naval Architects, 30, 94–103.	Federal Aviation Administration (2017). Airplane Weight and Balance Control. Advisory Circular AC 23-8B-1C.
כינויים	BEM theory, rotor performance prediction, actuator disk method	W&B, center of gravity, CG analysis
קשורות	3	3
תקציר	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.	Weight and balance analysis is the process of determining the total weight of an aircraft and the location of its center of gravity (CG) throughout its operational envelope. Essential for aircraft safety and performance, weight and balance ensures that the CG remains within allowable limits (forward and aft) to maintain stable flight and controllability. Regulatory certification requires comprehensive weight and balance documentation for every aircraft configuration.