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The higher the loading, the more power needed to maintain rotor speed. [3] A low disk loading is a direct indicator of high lift thrust efficiency. [4] Increasing the weight of a helicopter increases disk loading. For a given weight, a helicopter with shorter rotors will have higher disk loading, and will require more engine power to hover.
Rotor solidity is a function of the aspect ratio and number of blades in the rotor and is widely used as a parameter for ensuring geometric similarity in rotorcraft experiments. It provides a measure of how close a lifting rotor system is to an ideal actuator disk in momentum theory .
At a sufficiently high advance ratio, the blade will reach the stalling angle of attack and experience retreating blade stall. Specially designed airfoils can increase the operating advance ratio by utilizing high lift coefficient airfoils. Currently, single rotor helicopters are practically limited to advance ratios less than 0.7. [5]
Unequal rotor lift distribution [citation needed] is an effect where the blades of a helicopter rotor generate more lift at the rotor tips than at the rotor hub. [1]: 1:11 Overhead view of helicopter rotors. The rotor tips travel much faster than the inner sections, so produce more lift.
Stage 3: a steep decrease of the lift coefficient (lift break, lift stall) occurs as the DSV passes into the wake. Rotor map of dynamic stall locations for all conditions. Stage 4: full separation of the flow on the upper surface of the airfoil can be observed, accompanied by the peak of nose-down pitch moment.
Rotordynamics (or rotor dynamics) is a specialized branch of applied mechanics concerned with the behavior and diagnosis of rotating structures. It is commonly used to analyze the behavior of structures ranging from jet engines and steam turbines to auto engines and computer disk storage .
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A cyclorotor, cycloidal rotor, cycloidal propeller or cyclogiro, is a fluid propulsion device that converts shaft power into the acceleration of a fluid using a rotating axis perpendicular to the direction of fluid motion. It uses several blades with a spanwise axis parallel to the axis of rotation and perpendicular to the direction of fluid ...