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The most common stall-spin scenarios occur on takeoff (departure stall) and during landing (base to final turn) because of insufficient airspeed during these maneuvers. Stalls also occur during a go-around manoeuvre if the pilot does not properly respond to the out-of-trim situation resulting from the transition from low power setting to high ...
The adjacent blade stalls as a result of the incidence spike, thus causing stall cell "rotation" around the rotor. Stable local stalls can also occur which are axi-symmetric, covering the complete circumference of the compressor disc, but only a portion of its radial plane, with the remainder of the face of the compressor continuing to pass ...
In the case of airfoils, the pressure field modification results in an increase in pressure drag, and if severe enough will also result in stall and loss of lift, all of which are undesirable. For internal flows, flow separation produces an increase in the flow losses, and stall-type phenomena such as compressor surge, both undesirable ...
[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 ...
Under these circumstances, one wing stalls, or stalls more deeply than the other. The wing that stalls first drops, increasing its angle of attack and deepening the stall. [6] At least one wing must be stalled for a spin to occur. The other wing rises, decreasing its angle of attack, and the aircraft yaws towards the more deeply stalled wing.
The angle at which maximum lift coefficient occurs is the stall angle of the airfoil, which is approximately 10 to 15 degrees on a typical airfoil. The stall angle for a given profile is also increasing with increasing values of the Reynolds number, at higher speeds indeed the flow tends to stay attached to the profile for longer delaying the ...
Stall torque is the torque produced by a mechanical device whose output rotational speed is zero. It may also mean the torque load that causes the output rotational speed of a device to become zero, i.e., to cause stalling. Electric motors, steam engines and hydrodynamic transmissions are all capable of developing torque when stalled.
In most low-speed and low-pressure cases, rotating stall comes prior to compressor surge; [8] [9] however, a general cause-effect relation between rotating stall and compressor surge has not been determined yet. [6] On a constant speed line of a compressor, the mass flow rate decreases as the pressure delivered by the compressor gets higher.