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The use of g units refers to the fact that an observer on board an aircraft will experience an apparent acceleration of gravity (i.e. relative to their frame of reference) equal to load factor times the acceleration of gravity. For example, an observer on board an aircraft performing a turn with a load factor of 2 (i.e. a 2 g turn) will see ...
The "M" indicates it is a measure of pitching moment changes. The indicates the changes are in response to changes in angle of attack. This stability derivative is pronounced "see-em-alpha". It is one measure of how strongly an aircraft wants to fly "nose first", which is clearly very important.
In aerodynamics, the pitching moment on an airfoil is the moment (or torque) produced by the aerodynamic force with respect to the aerodynamic center on the airfoil . The pitching moment on the wing of an airplane is part of the total moment that must be balanced using the lift on the horizontal stabilizer . [ 1 ] :
In words, the wind axes force is equal to the centripetal acceleration. The moment equation is the time derivative of the angular momentum: = where M is the pitching moment, and B is the moment of inertia about the pitch axis. Let: =, the pitch rate. The equations of motion, with all forces and moments referred to wind axes are, therefore:
Strength depends upon material properties. The strength of a material depends on its capacity to withstand axial stress, shear stress, bending, and torsion.The strength of a material is measured in force per unit area (newtons per square millimetre or N/mm², or the equivalent megapascals or MPa in the SI system and often pounds per square inch psi in the United States Customary Units system).
is the force that is responsible for the rotation of the rotor blades; is the force that is responsible for the bending of the blades. Recall that for an isolated system the net angular momentum of the system is conserved. If the rotor acquired angular momentum, so must the fluid in the wake.
The Kutta–Joukowski theorem is a fundamental theorem in aerodynamics used for the calculation of lift of an airfoil (and any two-dimensional body including circular cylinders) translating in a uniform fluid at a constant speed so large that the flow seen in the body-fixed frame is steady and unseparated.
The Unit dummy force method provides a convenient means for computing displacements in structural systems. It is applicable for both linear and non-linear material behaviours as well as for systems subject to environmental effects, and hence more general than Castigliano's second theorem .