Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 70
Book Description
The oscillating air forces on a two-dimensional wing oscillating in pitch about the midchord have been measured at various mean angles of attack and at Mach numbers of 0.35 and 0.7. The magnitudes of normal-force and pitching-moment coefficients were much higher at high angles of attack than at low angles of attack for some conditions. Large regions of negative damping in pitch were found, and it was shown that the effect of increasing the Mach number from 0.35 to 0.7 was to decrease the initial angle of attack at which negative damping occurred. Measurements of the aerodynamic damping of a 10-percent-thick and of a 5-percent-thick finite-span wing oscillating in the first bending mode indicate no regions of negative damping for this type of motion over the range of variables covered. The damping measured at high angles of attack was generally larger than that at low angles of attack.
Measurement of Aerodynamic Forces for Various Mean Angles of Attach on an Airfoil Oscillating in Pitch and on Two Finite-Span Wings Oscillating in Bending with Emphasis on Damping in the Stall
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 70
Book Description
The oscillating air forces on a two-dimensional wing oscillating in pitch about the midchord have been measured at various mean angles of attack and at Mach numbers of 0.35 and 0.7. The magnitudes of normal-force and pitching-moment coefficients were much higher at high angles of attack than at low angles of attack for some conditions. Large regions of negative damping in pitch were found, and it was shown that the effect of increasing the Mach number from 0.35 to 0.7 was to decrease the initial angle of attack at which negative damping occurred. Measurements of the aerodynamic damping of a 10-percent-thick and of a 5-percent-thick finite-span wing oscillating in the first bending mode indicate no regions of negative damping for this type of motion over the range of variables covered. The damping measured at high angles of attack was generally larger than that at low angles of attack.
Publisher:
ISBN:
Category :
Languages : en
Pages : 70
Book Description
The oscillating air forces on a two-dimensional wing oscillating in pitch about the midchord have been measured at various mean angles of attack and at Mach numbers of 0.35 and 0.7. The magnitudes of normal-force and pitching-moment coefficients were much higher at high angles of attack than at low angles of attack for some conditions. Large regions of negative damping in pitch were found, and it was shown that the effect of increasing the Mach number from 0.35 to 0.7 was to decrease the initial angle of attack at which negative damping occurred. Measurements of the aerodynamic damping of a 10-percent-thick and of a 5-percent-thick finite-span wing oscillating in the first bending mode indicate no regions of negative damping for this type of motion over the range of variables covered. The damping measured at high angles of attack was generally larger than that at low angles of attack.
Measurement of Aerodynamic Forces for Various Mean Angles of Attack on an Airfoil Oscillating in Pitch and on Two Finite-span Wings Oscillating in Bending with Emphasis on Damping in the Stall
Author: A. Gerald Rainey
Publisher:
ISBN:
Category : Aerfoils
Languages : en
Pages : 33
Book Description
Measurements of the aerodynamic damping of a 10-percent-thick and of a 3-percent-thick finite-span wing oscillating in the first bending mode indicate no regions of negative damping for this type of motion over the range of variables covered. The damping measured at high angles of attack was generally larger than that at low angles of attack.
Publisher:
ISBN:
Category : Aerfoils
Languages : en
Pages : 33
Book Description
Measurements of the aerodynamic damping of a 10-percent-thick and of a 3-percent-thick finite-span wing oscillating in the first bending mode indicate no regions of negative damping for this type of motion over the range of variables covered. The damping measured at high angles of attack was generally larger than that at low angles of attack.
NASA Technical Note
Evaluation of an Aeroelastic Model Technique for Predicting Airplane Buffet Loads
Author: Perry W. Hanson
Publisher:
ISBN:
Category : Aeroelasticity
Languages : en
Pages : 68
Book Description
A wind-tunnel technique which makes use of a dynamically scaled aeroelastic model to predict full-scale airplane buffet loads during buffet boundary penetration is evaluated. A 1/8-scale flutter model of a fighter airplane with remotely controllable variable-sweep wings and trimming surfaces was used for the evaluation. The model was flown on a cable-mount system which permitted high lift forces comparable to those in maneuvering flight. Bending moments and accelerations due to buffet were measured on the flutter model and compared with those measured on the full-scale airplane in an independent flight buffet research study. It is concluded that the technique can provide valuable information on airplane buffet load characteristics not available from any other source except flight test.
Publisher:
ISBN:
Category : Aeroelasticity
Languages : en
Pages : 68
Book Description
A wind-tunnel technique which makes use of a dynamically scaled aeroelastic model to predict full-scale airplane buffet loads during buffet boundary penetration is evaluated. A 1/8-scale flutter model of a fighter airplane with remotely controllable variable-sweep wings and trimming surfaces was used for the evaluation. The model was flown on a cable-mount system which permitted high lift forces comparable to those in maneuvering flight. Bending moments and accelerations due to buffet were measured on the flutter model and compared with those measured on the full-scale airplane in an independent flight buffet research study. It is concluded that the technique can provide valuable information on airplane buffet load characteristics not available from any other source except flight test.
Measurement of Aerodynamic Forces on an Oscillating Airfoil
Author: Richard I. Windsor
Publisher:
ISBN:
Category : Aerofoils
Languages : en
Pages : 252
Book Description
A literature survey was conducted to determine the state of the art of measuring and predicting aerodynamic characteristics of oscillating air-foils. Aerodynamic forces on a two-dimensional NACA 0012 airfoil oscillating sinusoidally in pitch were measured by two techniques. The forces were obtained from pressure measurements and by means of strain gage balances. Pressure measurements were made on the airfoil oscillating in pitch about the quarter-chord point at various mean angles of attack. Strain gage balance readings were obtained for models with pitch axis located at 25, 37, and 50 percent chord points oscillating about various mean angles. Direct force measurements were employed in an effort to obtain drag data. Instantaneous pressure distributions are presneted for representative oscillating conditions. (Author).
Publisher:
ISBN:
Category : Aerofoils
Languages : en
Pages : 252
Book Description
A literature survey was conducted to determine the state of the art of measuring and predicting aerodynamic characteristics of oscillating air-foils. Aerodynamic forces on a two-dimensional NACA 0012 airfoil oscillating sinusoidally in pitch were measured by two techniques. The forces were obtained from pressure measurements and by means of strain gage balances. Pressure measurements were made on the airfoil oscillating in pitch about the quarter-chord point at various mean angles of attack. Strain gage balance readings were obtained for models with pitch axis located at 25, 37, and 50 percent chord points oscillating about various mean angles. Direct force measurements were employed in an effort to obtain drag data. Instantaneous pressure distributions are presneted for representative oscillating conditions. (Author).
Determination of Influence Coefficients
Report
Wind-tunnel Investigation of a Number of Total-pressure Tubes at High Angles of Attack
Author: A. Gerald Rainey
Publisher:
ISBN:
Category : Aerodynamics
Languages : en
Pages : 316
Book Description
Publisher:
ISBN:
Category : Aerodynamics
Languages : en
Pages : 316
Book Description
Report
Author: United States. National Advisory Committee for Aeronautics
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 52
Book Description
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 52
Book Description
Measurement of Aerodynamic Forces on an Oscillating Airfoil
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
A literature survey was conducted to determine the state of the art of measuring and predicting aerodynamic characteristics of oscillating air-foils. Aerodynamic forces on a two-dimensional NACA 0012 airfoil oscillating sinusoidally in pitch were measured by two techniques. The forces were obtained from pressure measurements and by means of strain gage balances. Pressure measurements were made on the airfoil oscillating in pitch about the quarter-chord point at various mean angles of attack. Strain gage balance readings were obtained for models with pitch axis located at 25, 37, and 50 percent chord points oscillating about various mean angles. Direct force measurements were employed in an effort to obtain drag data. Instantaneous pressure distributions are presneted for representative oscillating conditions. (Author).
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
A literature survey was conducted to determine the state of the art of measuring and predicting aerodynamic characteristics of oscillating air-foils. Aerodynamic forces on a two-dimensional NACA 0012 airfoil oscillating sinusoidally in pitch were measured by two techniques. The forces were obtained from pressure measurements and by means of strain gage balances. Pressure measurements were made on the airfoil oscillating in pitch about the quarter-chord point at various mean angles of attack. Strain gage balance readings were obtained for models with pitch axis located at 25, 37, and 50 percent chord points oscillating about various mean angles. Direct force measurements were employed in an effort to obtain drag data. Instantaneous pressure distributions are presneted for representative oscillating conditions. (Author).