Author: Santhosh B. Mamidala
Publisher:
ISBN: 9789180402293
Category :
Languages : en
Pages :
Book Description
Effects of Free-stream Turbulence and Three-dimensional Roughness on Boundary Layer Transition
Author: Santhosh B. Mamidala
Publisher:
ISBN: 9789180402293
Category :
Languages : en
Pages :
Book Description
Publisher:
ISBN: 9789180402293
Category :
Languages : en
Pages :
Book Description
Boundary Layer Transition at Supersonic Speeds
Author: E. R. Van Driest
Publisher:
ISBN:
Category : Aerodynamics, Supersonic
Languages : en
Pages : 108
Book Description
Experiments carried out in the 12-inch supersonic wind tunnel to investigate the effect of three dimensional roughness elements (spheres) on boundary-layer transition on a 10-degree (apex angle) cone without heat transfer are described. The local Mach number for these tests was 2.71. The data show clearly that the minimum (effective) size of trip required to bring transition to its lowest Reynolds number varies power of the distance from the apex of the cone to the trip. Use of available data at other Mach numbers indicates that the Mach number influence for effective tripping is taken into account by a simple expression. Some remarks concerning the roughness variation for transition on a blunt body are made. Finally, a general criterion is introduced which gives insight to the transition phenomenon and anticipates effects of external and internal disturbances, Mach number transfer.
Publisher:
ISBN:
Category : Aerodynamics, Supersonic
Languages : en
Pages : 108
Book Description
Experiments carried out in the 12-inch supersonic wind tunnel to investigate the effect of three dimensional roughness elements (spheres) on boundary-layer transition on a 10-degree (apex angle) cone without heat transfer are described. The local Mach number for these tests was 2.71. The data show clearly that the minimum (effective) size of trip required to bring transition to its lowest Reynolds number varies power of the distance from the apex of the cone to the trip. Use of available data at other Mach numbers indicates that the Mach number influence for effective tripping is taken into account by a simple expression. Some remarks concerning the roughness variation for transition on a blunt body are made. Finally, a general criterion is introduced which gives insight to the transition phenomenon and anticipates effects of external and internal disturbances, Mach number transfer.
Effect of Distributed Three-dimensional Roughness and Surface Cooling on Boundary-layer Transition and Lateral Spread of Turbulence at Supersonic Speeds
Author: Albert L. Braslow
Publisher:
ISBN:
Category : Numerical analysis
Languages : en
Pages : 48
Book Description
Publisher:
ISBN:
Category : Numerical analysis
Languages : en
Pages : 48
Book Description
Investigation of Effects of Roughness, Surface Cooling, and Shock Impingement on Boundary-layer Transition on a Two-dimensional Wing
Author: K. R. Czarnecki
Publisher:
ISBN:
Category : Aerodynamics
Languages : en
Pages : 46
Book Description
Publisher:
ISBN:
Category : Aerodynamics
Languages : en
Pages : 46
Book Description
Review of the Effect of Distributed Surface Roughness on Boundary-layer Transition
Author: A. L. Braslow
Publisher:
ISBN:
Category : Boundary layer
Languages : en
Pages : 13
Book Description
A discussion is presented on the transition phenomena associated with distributed roughness, a correlation of three-dimensional roughness effects at both subsonic and supersonic speeds, and the effect of laminar boundary-layer stability as influenced by heat transfer, pressure gradients, and boundary-layer control on the sensitivity of laminar flow to distributed roughness. Results indicate that the transition-triggering mechanism of three-dimensionaltype surface roughness appears to be the same at supersonic and subsonic speeds. In either case, a Reynolds number based on the height of the roughness and the local flow conditions at the top of the roughness can be used to predict with reasonable accuracy the height of threedimensional roughness required to cause premature transition. Neither the three-dimensional roughness Reynolds number nor the lateral spread of turbulence behind the roughness is changed to any important extent by increasing the laminar boundary-layer stability to theoretically small disturbances. Therefore, for a given stream Mach number and Reynolds number, surface cooling, boundary-layer suction, or a favorable pressure gradient will, in the presence of three-dimensional roughness, promote rather than delay transition. (Author).
Publisher:
ISBN:
Category : Boundary layer
Languages : en
Pages : 13
Book Description
A discussion is presented on the transition phenomena associated with distributed roughness, a correlation of three-dimensional roughness effects at both subsonic and supersonic speeds, and the effect of laminar boundary-layer stability as influenced by heat transfer, pressure gradients, and boundary-layer control on the sensitivity of laminar flow to distributed roughness. Results indicate that the transition-triggering mechanism of three-dimensionaltype surface roughness appears to be the same at supersonic and subsonic speeds. In either case, a Reynolds number based on the height of the roughness and the local flow conditions at the top of the roughness can be used to predict with reasonable accuracy the height of threedimensional roughness required to cause premature transition. Neither the three-dimensional roughness Reynolds number nor the lateral spread of turbulence behind the roughness is changed to any important extent by increasing the laminar boundary-layer stability to theoretically small disturbances. Therefore, for a given stream Mach number and Reynolds number, surface cooling, boundary-layer suction, or a favorable pressure gradient will, in the presence of three-dimensional roughness, promote rather than delay transition. (Author).
Effect of Surface Waviness on Transition in Three-Dimensional Boundary-Layer Flow
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 46
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 46
Book Description
Instability, Transition, and Turbulence
Author: M.Y. Hussaini
Publisher: Springer Science & Business Media
ISBN: 1461229561
Category : Science
Languages : en
Pages : 626
Book Description
This volume contains the proceedings of the Workshop on In stability, Transition and Turbulence, sponsored by the Institute for Computer Applications in Science and Engineering (ICASE) and the NASA Langley Research Center (LaRC), during July 8 to August 2, 1991. This is the second workshop in the series on the subject. The first was held in 1989, and its proceedings were published by Springer-Verlag under the title "Instability and Transition" edited by M. Y. Hussaini and R. G. Voigt. The objectives of these work shops are to i) expose the academic community to current technologically im portant issues of transition and turbulence in shear flows over the entire speed range, ii) acquaint the academic community with the unique combination of theoretical, computational and experimental capabilities at LaRC and foster interaction with these capabilities, and iii) accelerate progress in elucidating the fundamental phenomena of transition and turbulence, leading to improved transition and turbulence modeling in design methodologies. The research areas covered in these proceedings include receptiv ity and roughness, nonlinear theories of transition, numerical simu lation of spatially evolving flows, modelling of transitional and fully turbulent flows as well as some experiments on instability and tran sition. In addition a one-day mini-symposium was held to discuss 1 recent and planned experiments on turbulent flow over a backward facing step.
Publisher: Springer Science & Business Media
ISBN: 1461229561
Category : Science
Languages : en
Pages : 626
Book Description
This volume contains the proceedings of the Workshop on In stability, Transition and Turbulence, sponsored by the Institute for Computer Applications in Science and Engineering (ICASE) and the NASA Langley Research Center (LaRC), during July 8 to August 2, 1991. This is the second workshop in the series on the subject. The first was held in 1989, and its proceedings were published by Springer-Verlag under the title "Instability and Transition" edited by M. Y. Hussaini and R. G. Voigt. The objectives of these work shops are to i) expose the academic community to current technologically im portant issues of transition and turbulence in shear flows over the entire speed range, ii) acquaint the academic community with the unique combination of theoretical, computational and experimental capabilities at LaRC and foster interaction with these capabilities, and iii) accelerate progress in elucidating the fundamental phenomena of transition and turbulence, leading to improved transition and turbulence modeling in design methodologies. The research areas covered in these proceedings include receptiv ity and roughness, nonlinear theories of transition, numerical simu lation of spatially evolving flows, modelling of transitional and fully turbulent flows as well as some experiments on instability and tran sition. In addition a one-day mini-symposium was held to discuss 1 recent and planned experiments on turbulent flow over a backward facing step.
Boundary-layer Receptivity
Author: Shelly Anne Spencer
Publisher:
ISBN:
Category : Boundary layer
Languages : en
Pages : 182
Book Description
Publisher:
ISBN:
Category : Boundary layer
Languages : en
Pages : 182
Book Description
A Review of Factors Affecting Boundary-layer Transition
Author: Albert L. Braslow
Publisher:
ISBN:
Category : Aerodynamics, Supersonic
Languages : en
Pages : 36
Book Description
Publisher:
ISBN:
Category : Aerodynamics, Supersonic
Languages : en
Pages : 36
Book Description
Three-dimensional Turbulent Boundary Layers
Author: O. Sendstad
Publisher:
ISBN:
Category : Simulation methods
Languages : en
Pages : 130
Book Description
Publisher:
ISBN:
Category : Simulation methods
Languages : en
Pages : 130
Book Description