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[1] [2] Unlike fixed-wing aircraft, of which the stall occurs at relatively low flight speed, the dynamic stall on a helicopter rotor emerges at high airspeeds or/and during manoeuvres with high load factors of helicopters, when the angle of attack(AOA) of blade elements varies intensively due to time-dependent blade flapping, cyclic pitch and ...
Dynamic stall is an effect most associated with helicopters and flapping wings, though also occurs in wind turbines, [41] and due to gusting airflow. During forward flight, some regions of a helicopter blade may incur flow that reverses (compared to the direction of blade movement), and thus includes rapidly changing angles of attack.
Retreating blade stall is a hazardous flight condition in helicopters and other rotary wing aircraft, where the retreating rotor blade has a lower relative blade speed, combined with an increased angle of attack, causing a stall and loss of lift. Retreating blade stall is the primary limiting factor of a helicopter's never exceed speed, V NE. [1]
Its comprises helicopter aerodynamics, stability, control, structural dynamics, vibration, and aeroelastic and aeromechanical stability. [1] By studying the forces in helicopter flight, improved helicopter designs can be made, though due to the scale and speed of the dynamics, physical testing is non-trivial and expensive.
This includes but its not limited to: Dynamic rollover, Ground resonance, Loss of tail-rotor effectiveness, Retreating blade stall,Dynamic stall, Vortex ring state, Servo transparency, Mast bumping, and Tailstrike. Because the main rotor is vital to keeping a helicopter in the air, any damage to can have disastrous consequences.
Pages in category "Helicopter aerodynamics" The following 23 pages are in this category, out of 23 total. ... Dynamic rollover; Dynamic stall on helicopter rotors; F.
As a predominant source of noise, BVI phenomenon can be detrimental to blade structure integrity as well because of the unsteady fluctuation of aerodynamics, such as vortex buffeting and dynamic stall in the retreating blade. Therefore, BVI becomes a prime concern in the helicopter research field.
In aviation, and in particular in helicopters, servo transparency (also called servo reversibility or jack stall), [1] is a phenomenon affecting the servomechanisms (or servos) that assist a helicopter's flight controls, which, in certain flight conditions, can result in a significant stiffening of the controls handled by the pilot.