Author: James M. Kendall
Publisher:
ISBN:
Category : Laminar boundary layer
Languages : en
Pages : 86
Book Description
Part I: Hot wire anemometry has been employed to determine certain characteristics of the turbulence in the free-stream of a low-speed, low-turbulence wind tunnel and to study the influence on such turbulence upon the fluctuations within a flat-plate boundary layer. A technique was employed which provided information concerning the propagation speed of the disturbances and this was used as a means of classification as to type or cause. It was found that Tollmien-Schlichting waves did not possess significant energy until a Reynolds number considerably higher than that of the theoretical neutral point was attained and that the subsequent growth exceeded the prediction of linear analysis. Part II: Distributed roughness present upon an aerodynamic surface alters the laminar boundary layer mean velocity profile such as to increase the instability presented here of the profile distortion for the case of small roughness in a Blasius boundary layer. The roughnesses tested include a single protuberance at Reynolds numbers below 50, the interaction between two such elements, the interaction between one element and a multitude of others, and the distortion due to distributed roughness. (Author).
Study of the Effect of Free-stream Turbulence Upon Disturbances in the Pre-transitional Laminar Boundary Layer
Author: James M. Kendall
Publisher:
ISBN:
Category : Laminar boundary layer
Languages : en
Pages : 86
Book Description
Part I: Hot wire anemometry has been employed to determine certain characteristics of the turbulence in the free-stream of a low-speed, low-turbulence wind tunnel and to study the influence on such turbulence upon the fluctuations within a flat-plate boundary layer. A technique was employed which provided information concerning the propagation speed of the disturbances and this was used as a means of classification as to type or cause. It was found that Tollmien-Schlichting waves did not possess significant energy until a Reynolds number considerably higher than that of the theoretical neutral point was attained and that the subsequent growth exceeded the prediction of linear analysis. Part II: Distributed roughness present upon an aerodynamic surface alters the laminar boundary layer mean velocity profile such as to increase the instability presented here of the profile distortion for the case of small roughness in a Blasius boundary layer. The roughnesses tested include a single protuberance at Reynolds numbers below 50, the interaction between two such elements, the interaction between one element and a multitude of others, and the distortion due to distributed roughness. (Author).
Publisher:
ISBN:
Category : Laminar boundary layer
Languages : en
Pages : 86
Book Description
Part I: Hot wire anemometry has been employed to determine certain characteristics of the turbulence in the free-stream of a low-speed, low-turbulence wind tunnel and to study the influence on such turbulence upon the fluctuations within a flat-plate boundary layer. A technique was employed which provided information concerning the propagation speed of the disturbances and this was used as a means of classification as to type or cause. It was found that Tollmien-Schlichting waves did not possess significant energy until a Reynolds number considerably higher than that of the theoretical neutral point was attained and that the subsequent growth exceeded the prediction of linear analysis. Part II: Distributed roughness present upon an aerodynamic surface alters the laminar boundary layer mean velocity profile such as to increase the instability presented here of the profile distortion for the case of small roughness in a Blasius boundary layer. The roughnesses tested include a single protuberance at Reynolds numbers below 50, the interaction between two such elements, the interaction between one element and a multitude of others, and the distortion due to distributed roughness. (Author).
Scientific and Technical Aerospace Reports
NASA Technical Paper
NASA Reference Publication
Applied Mechanics Reviews
Monthly Catalog of United States Government Publications
Author:
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 1698
Book Description
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 1698
Book Description
Symposium on Naval Hydrodynamics
AFOSR Technical Report Summaries
Instability and Transition
Author: M.Y. Hussaini
Publisher: Springer Science & Business Media
ISBN: 1461234301
Category : Science
Languages : en
Pages : 462
Book Description
These two volumes contain the proceedings of the workshop on the Institute for Computer Instability and Transition, sponsored by Applications in Science and Engineering (ICASE) and the Langley Research Center (LaRC), during May 15 to June 9, 1989. The work shop coincided with the initiation of a new, focused research pro gram on instability and transition at LaRC. The objectives of the workshop were to (i) expose the academic community to current technologically important issues of instability and transition in shear flows over the entire speed range, (ii) acquaint the academic com munity with the unique combination of theoretical, computational and experimental capabilities at LaRC and foster interaction with these facilities, (iii) review current state-of-the-art and propose fu ture directions for instability and transition research, (iv) accelerate progress in elucidating basic understanding of transition phenomena and in transferring this knowledge into improved design methodolo gies through improved transition modeling, and (v) establish mech anisms for continued interaction. The objectives (i) to (iii) were of course immediately met. It is still premature to assess whether ob jectives (iv) and (v) are achieved. The workshop program consisted of tutorials, research presenta tions, panel discussions, experimental and computational demonstra tions, and collaborative projects.
Publisher: Springer Science & Business Media
ISBN: 1461234301
Category : Science
Languages : en
Pages : 462
Book Description
These two volumes contain the proceedings of the workshop on the Institute for Computer Instability and Transition, sponsored by Applications in Science and Engineering (ICASE) and the Langley Research Center (LaRC), during May 15 to June 9, 1989. The work shop coincided with the initiation of a new, focused research pro gram on instability and transition at LaRC. The objectives of the workshop were to (i) expose the academic community to current technologically important issues of instability and transition in shear flows over the entire speed range, (ii) acquaint the academic com munity with the unique combination of theoretical, computational and experimental capabilities at LaRC and foster interaction with these facilities, (iii) review current state-of-the-art and propose fu ture directions for instability and transition research, (iv) accelerate progress in elucidating basic understanding of transition phenomena and in transferring this knowledge into improved design methodolo gies through improved transition modeling, and (v) establish mech anisms for continued interaction. The objectives (i) to (iii) were of course immediately met. It is still premature to assess whether ob jectives (iv) and (v) are achieved. The workshop program consisted of tutorials, research presenta tions, panel discussions, experimental and computational demonstra tions, and collaborative projects.
NASA Scientific and Technical Reports
Author: United States. National Aeronautics and Space Administration Scientific and Technical Information Division
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 2300
Book Description
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 2300
Book Description