Search results
Results From The WOW.Com Content Network
The overall propulsive efficiency (an extension of effective power ()) is developed from the propulsive coefficient (), which is derived from the installed shaft power modified by the effective power for the hull with appendages (′), the propeller's thrust power (), and the relative rotative efficiency.
Diameter of the propeller. The propeller advance ratio or coefficient is a dimensionless number used in aeronautics and marine hydrodynamics to describe the relationship between the speed at which a vehicle (like an airplane or a boat) is moving forward and the speed at which its propeller is turning.
The thrust-to-weight ratio is usually calculated from initial gross weight at sea level on earth [6] and is sometimes called thrust-to-Earth-weight ratio. [7] The thrust-to-Earth-weight ratio of a rocket or rocket-propelled vehicle is an indicator of its acceleration expressed in multiples of earth's gravitational acceleration, g 0. [5]
The propellers on some aircraft can operate with a negative blade pitch angle, and thus reverse the thrust from the propeller. This is known as Beta Pitch. Reverse thrust is used to help slow the aircraft after landing and is particularly advantageous when landing on a wet runway as wheel braking suffers reduced effectiveness.
RncM = Reynolds number of the model propeller; cM = expanded blade width of the section at 0.75R of the model propeller; υM = Kinematic viscosity of the water for model; KTM, KTS = thrust coefficient of the model and ship propeller respectively; KQM, KQS = torque coefficient of the model and ship propeller respectively
For example, when rotor thrust coefficient is assumed to be constant, the weighing function comes out to be: = and the corresponding weighted solidity ratio is known as the thrust-weighted solidity ratio. [2] When rotor power or torque coefficient is assumed constant, the weighing function is:
The blades are the foil section plates that develop thrust when the propeller is rotated The hub is the central part of the propeller, ... (high blade lift coefficient).
Consider the element at radius r, shown in Fig. 1, which has the infinitesimal length dr and the width b. The motion of the element in an aircraft propeller in flight is along a helical path determined by the forward velocity V of the aircraft and the tangential velocity 2πrn of the element in the plane of the propeller disc, where n represents the revolutions per unit time.