Author: Charles O. Adler
Publisher:
ISBN:
Category : Airplanes
Languages : en
Pages : 242
Book Description
Vortex Induced Effects on Slender Aircraft
Author: Charles O. Adler
Publisher:
ISBN:
Category : Airplanes
Languages : en
Pages : 242
Book Description
Publisher:
ISBN:
Category : Airplanes
Languages : en
Pages : 242
Book Description
Theoretical Prediction of the Effects of Vortex Flows on the Loading, Forces, and Moments of Slender Aircraft
Author: J. Richard Spahr
Publisher:
ISBN:
Category : Aerodynamics
Languages : en
Pages : 48
Book Description
A theoretical method based on slender-body theory is presented for the stepwise calculation of vortex paths in the presence of wing-body combinations and the determination of the load distributions, forces, and moments on the combinations due to the vortices. Comparisons of calculated and experimental results indicate that the vortex paths and the forces induced by the vortices can be closely predicted by the calculative method only for slender configurations. The total forces and moments, however, in many cases can be predicted adequately for nonslender as well as slender triangular-wing configurations.
Publisher:
ISBN:
Category : Aerodynamics
Languages : en
Pages : 48
Book Description
A theoretical method based on slender-body theory is presented for the stepwise calculation of vortex paths in the presence of wing-body combinations and the determination of the load distributions, forces, and moments on the combinations due to the vortices. Comparisons of calculated and experimental results indicate that the vortex paths and the forces induced by the vortices can be closely predicted by the calculative method only for slender configurations. The total forces and moments, however, in many cases can be predicted adequately for nonslender as well as slender triangular-wing configurations.
Theoretical Prediction of Effects of Vortex Flows on Loading, Forces, and Moments of Slender Aircraft [with List of References]
Author:
Publisher:
ISBN:
Category : Aerodynamics
Languages : en
Pages : 37
Book Description
Publisher:
ISBN:
Category : Aerodynamics
Languages : en
Pages : 37
Book Description
Vortex-Induced Asymmetric Loads on Slender Vehicles
Author: Lars E. Ericsson
Publisher:
ISBN:
Category :
Languages : en
Pages : 237
Book Description
The steady and unsteady vortex-induced asymmetric loads on slender vehicles were investigated. The study reviewed pertinent two- and three-dimensional data; developed analytic means for predicting the upper limit for vortex-induced asymmetric loads; and assessed the importance of these loads to the vehicle dynamics of slender bodies of revolution. The study showed boundary layer transition to have a dominant influence on static and dynamic vortex-induced loads. The predicted upper limit for vortex-induced asymmetric loads bounds all available experimental data from subcritical to supercritical Reynolds numbers. The most powerful dynamic effect is that of the moving wall at the separation point, which has a wall-jet-like effect on the boundary layer separation and transition. Preliminary experimental results indicate that because of this effect the dynamic stability parameters due to pitching and coning can be one order of magnitude larger than those occurring in attached flow at lower angles-of-attack. A very important effect of asymmetric vortices existing at high angles-of-attack is to provide a coupling mechanism at zero sideslip between longitudinal and lateral degrees of freedom. As these cross coupling effects are very large, highly nonlinear, often discontinuous and associated with hysteresis effects, with especially large impact on the vehicle dynamics, they are of great concern to missile and aircraft designers.
Publisher:
ISBN:
Category :
Languages : en
Pages : 237
Book Description
The steady and unsteady vortex-induced asymmetric loads on slender vehicles were investigated. The study reviewed pertinent two- and three-dimensional data; developed analytic means for predicting the upper limit for vortex-induced asymmetric loads; and assessed the importance of these loads to the vehicle dynamics of slender bodies of revolution. The study showed boundary layer transition to have a dominant influence on static and dynamic vortex-induced loads. The predicted upper limit for vortex-induced asymmetric loads bounds all available experimental data from subcritical to supercritical Reynolds numbers. The most powerful dynamic effect is that of the moving wall at the separation point, which has a wall-jet-like effect on the boundary layer separation and transition. Preliminary experimental results indicate that because of this effect the dynamic stability parameters due to pitching and coning can be one order of magnitude larger than those occurring in attached flow at lower angles-of-attack. A very important effect of asymmetric vortices existing at high angles-of-attack is to provide a coupling mechanism at zero sideslip between longitudinal and lateral degrees of freedom. As these cross coupling effects are very large, highly nonlinear, often discontinuous and associated with hysteresis effects, with especially large impact on the vehicle dynamics, they are of great concern to missile and aircraft designers.
Vortex Interference on Slender Airplanes
Author: Alvin H. Sacks
Publisher:
ISBN:
Category : Airplanes
Languages : en
Pages : 702
Book Description
It is found that the impulse of each shed vortex and its image vortex in a transformed circle plane enters into all the interference forces and moments on the airplane. A simple theorem is given for the interference forces in steady straight flight which are found to depend on this impulse evaluated only at the wing trailing edge and at the base of the configuration.
Publisher:
ISBN:
Category : Airplanes
Languages : en
Pages : 702
Book Description
It is found that the impulse of each shed vortex and its image vortex in a transformed circle plane enters into all the interference forces and moments on the airplane. A simple theorem is given for the interference forces in steady straight flight which are found to depend on this impulse evaluated only at the wing trailing edge and at the base of the configuration.
Theoretical Prediction of the Effects of Vortex Flows on the Loading, Forces, and Moments of Slender Aircraft
Author: J. Richard Spahr
Publisher:
ISBN:
Category : Aerodynamics
Languages : en
Pages : 102
Book Description
Publisher:
ISBN:
Category : Aerodynamics
Languages : en
Pages : 102
Book Description
NASA Technical Report
Author:
Publisher:
ISBN:
Category : Aerodynamics
Languages : en
Pages : 1126
Book Description
Publisher:
ISBN:
Category : Aerodynamics
Languages : en
Pages : 1126
Book Description
Aircraft Vortex Wakes in Relation to Terminal Operations
Author: Joseph W. Wetmore
Publisher:
ISBN:
Category : Eddies
Languages : en
Pages : 32
Book Description
Publisher:
ISBN:
Category : Eddies
Languages : en
Pages : 32
Book Description
Vortex wakes of Aircrafts
Author: A.S. Ginevsky
Publisher: Springer Science & Business Media
ISBN: 3642017606
Category : Mathematics
Languages : en
Pages : 166
Book Description
Investigation of vortex wakes behind various aircraft, especially behind wide bodied and heavy cargo ones, is of both scientific and practical in terest. The vortex wakes shed from the wing’s trailing edge are long lived and attenuate only atdistances of10–12kmbehindthe wake generating aircraft. The encounter of other aircraft with the vortex wake of a heavy aircraft is open to catastrophic hazards. For example, air refueling is adangerous operationpartly due to thepossibility of the receiver aircraft’s encountering the trailing wake of the tanker aircraft. It is very important to know the behavior of vortex wakes of aircraft during theirtakeoff andlanding operations whenthe wakes canpropagate over the airport’s ground surface and be a serious hazard to other depart ing or arriving aircraft. This knowledge can help in enhancing safety of aircraft’s movements in the terminal areas of congested airports where the threat of vortex encounters limits passenger throughput. Theoreticalinvestigations of aircraft vortex wakes arebeingintensively performedinthe major aviationnations.Usedforthispurpose are various methods for mathematical modeling of turbulent flows: direct numerical simulation based on the Navier–Stokes equations, large eddy simulation using the Navier–Stokes equations in combination with subrigid scale modeling, simulation based on the Reynolds equations closed with a differential turbulence model. These approaches are widely used in works of Russian and other countries’ scientists. It should be emphasized that the experiments in wind tunnels and studies of natural vortex wakes behind heavy and light aircraft in flight experiments are equally important.
Publisher: Springer Science & Business Media
ISBN: 3642017606
Category : Mathematics
Languages : en
Pages : 166
Book Description
Investigation of vortex wakes behind various aircraft, especially behind wide bodied and heavy cargo ones, is of both scientific and practical in terest. The vortex wakes shed from the wing’s trailing edge are long lived and attenuate only atdistances of10–12kmbehindthe wake generating aircraft. The encounter of other aircraft with the vortex wake of a heavy aircraft is open to catastrophic hazards. For example, air refueling is adangerous operationpartly due to thepossibility of the receiver aircraft’s encountering the trailing wake of the tanker aircraft. It is very important to know the behavior of vortex wakes of aircraft during theirtakeoff andlanding operations whenthe wakes canpropagate over the airport’s ground surface and be a serious hazard to other depart ing or arriving aircraft. This knowledge can help in enhancing safety of aircraft’s movements in the terminal areas of congested airports where the threat of vortex encounters limits passenger throughput. Theoreticalinvestigations of aircraft vortex wakes arebeingintensively performedinthe major aviationnations.Usedforthispurpose are various methods for mathematical modeling of turbulent flows: direct numerical simulation based on the Navier–Stokes equations, large eddy simulation using the Navier–Stokes equations in combination with subrigid scale modeling, simulation based on the Reynolds equations closed with a differential turbulence model. These approaches are widely used in works of Russian and other countries’ scientists. It should be emphasized that the experiments in wind tunnels and studies of natural vortex wakes behind heavy and light aircraft in flight experiments are equally important.
Aerodynamics
Author: Theodore Von Kármán
Publisher: Courier Corporation
ISBN: 9780486434858
Category : Technology & Engineering
Languages : en
Pages : 226
Book Description
Charming, reader-friendly chronicle by a famous pioneer in aerodynamic research traces the development of dynamic flight from the time of Newton through the 20th century. It recounts struggles of engineers and physicists with problems associated with lift, drag, stability, aeroelasticity, and the sound barrier. 72 figures. 1957 edition.
Publisher: Courier Corporation
ISBN: 9780486434858
Category : Technology & Engineering
Languages : en
Pages : 226
Book Description
Charming, reader-friendly chronicle by a famous pioneer in aerodynamic research traces the development of dynamic flight from the time of Newton through the 20th century. It recounts struggles of engineers and physicists with problems associated with lift, drag, stability, aeroelasticity, and the sound barrier. 72 figures. 1957 edition.