Air Propellers in Yaw

Air Propellers in Yaw PDF Author: Everett Parker Lesley
Publisher:
ISBN:
Category : Propellers, Aerial
Languages : en
Pages : 15

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Book Description

Air Propellers in Yaw

Air Propellers in Yaw PDF Author: Everett Parker Lesley
Publisher:
ISBN:
Category : Propellers, Aerial
Languages : en
Pages : 15

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Book Description


Tests on Air Propellers in Yaw

Tests on Air Propellers in Yaw PDF Author: William Frederick Durand
Publisher:
ISBN:
Category :
Languages : en
Pages : 37

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Air Propellers in Yaw

Air Propellers in Yaw PDF Author: Bruce Morgan Richardson
Publisher:
ISBN:
Category : Propellers, Aerial
Languages : en
Pages :

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Tests on Air Propellers in Yaw

Tests on Air Propellers in Yaw PDF Author: United States. National Advisory Committee for Aeronautics
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 37

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Air Propeller in Yaw

Air Propeller in Yaw PDF Author: E. P. Lesley
Publisher:
ISBN:
Category :
Languages : en
Pages : 15

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Propellers in Yaw

Propellers in Yaw PDF Author: Herbert S. Ribner
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 88

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Summary: It was realized as early as 1909 that a propeller in yaw develops a side force like that of a fin. In 1917, R.G. Harris expressed this force in terms of the torque coefficient for the unyawed propeller. Of several attempts to express the side force directly in terms of the shape of the blades, however, none has been completely satisfactory. An analysis that incorporates induction effects not adequately covered in previous work and that gives good agreement with experiment over a wide range of operating conditions is presented herein. The present analysis shows that the fin analogy may be extended to the form of the side-force expression and that the effective fin area may be taken as the projected side area of the propeller. The effective aspect ratio is of the order of 8 and the appropriate dynamic pressure is roughly that at the propeller disk as augmented by the inflow. The variation of the inflow velocity, for a fixed-pitch propeller, accounts for most of the variation of side force with advance-diameter ration V/nD.

Experimental Research on Air Propellers

Experimental Research on Air Propellers PDF Author: United States. National Advisory Committee for Aeronautics
Publisher:
ISBN:
Category : Aerofoils
Languages : en
Pages : 218

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Alternating-current Equipment for the Measurement of Fluctuations of Air Speed in Turbulent Flow

Alternating-current Equipment for the Measurement of Fluctuations of Air Speed in Turbulent Flow PDF Author: Everett Parker Lesley
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 108

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The Problem of the Propeller in Yaw with Special Reference to Airplane Stability

The Problem of the Propeller in Yaw with Special Reference to Airplane Stability PDF Author: Franz Misztal
Publisher:
ISBN:
Category : Propellers, Aerial
Languages : en
Pages : 33

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The quantity of air which the disk area described by propeller blades travels through, is accelerated rearward conformably to the momentum of the forces acting on the propeller. The accelerated air mass forms behind the propeller the so-called slipstream, in which among others, the mean velocity of advance is increased. If the propeller axis slopes toward the relative flight direction, the slipstream direction likewise changes, i.e., it sets up a downwash behind the propeller. It was shown how this deviation can be mathematically defined. With appreciable slope the momentum of the slipstream is partially split up in the surrounding air because of the circulation, and the downwash of the slipstream is diminished.

Formulas for Propellers in Yaw and Charts of the Side-force Derivative

Formulas for Propellers in Yaw and Charts of the Side-force Derivative PDF Author: Herbert S. Ribner
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 28

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Summary: General formulas are given for propellers for the rate of change of side-force coefficient with angle of yaw and for the rate of change of pitching-moment coefficient with angle of yaw. Charts of the side-force derivative are given for two propellers of different plan form. The charts cover solidities of two to six blades and single and dual rotation. The blade angles range from 15° or 20° to 60°. The equations, and the charts computed from the equations, are based on an unpublished analysis, which incorporates factors not adequately covered in previously published work and gives good agreement with experiment over a wide range of operating conditions. A study of the equations indicates that they are consistent with the following physical interpretation: In developing side force, the propeller acts like a fin of which the area is the projected side area of the propeller, the effective aspect ratio is of the order of 8, and the effective dynamic pressure is roughly that at the propeller disk as augmented by the inflow. The variation of the inflow velocity, for a fixed-pitch propeller, accounts for most of the variation of side force with advance-diameter ratio. The charts may be applied to obtain the rate of change of normal-force coefficient with angle of attack of the axis of rotation if proper account is taken of the upwash or downwash from the wing.