Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 226
Book Description
Two- and Three-dimensional Blade Vortex Interactions
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 226
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 226
Book Description
Full-Potential Modeling of Blade-Vortex Interactions
Author: Henry E. Jones
Publisher:
ISBN:
Category : Unsteady flow (Aerodynamics)
Languages : en
Pages : 96
Book Description
A study of the full-potential modeling of a blade-vortex interaction was made. A primary goal of this study was to investigate the effectiveness of the various methods of modeling the vortex. The model problem restricts the interaction to that of an infinite wing with an infinite line vortex moving parallel to its leading edge. This problem provides a convenient testing ground for the various methods of modeling the vortex while retaining the essential physics of the full three-dimensional interaction. A full-potential algorithm specifically tailored to solve the blade-vortex interaction (BVI) was developed to solve this problem. The basic algorithm was modified to include the effect of a vortex passing near the airfoil. Four different methods of modeling the vortex were used: (1) the angle-of-attack methods, (2) the lifting-surface method, (3) the branch-cut method, and (4) the split-potential method. A side-by-side comparison of the four models was conducted. these comparisons included comparing generated velocity fields, a subcritical interaction, and a critical interaction. The subcritical and critical interactions are compared with experimentally generate results. The split-potential model was used to make a survey of some of the more critical parameters which affect the BVI.
Publisher:
ISBN:
Category : Unsteady flow (Aerodynamics)
Languages : en
Pages : 96
Book Description
A study of the full-potential modeling of a blade-vortex interaction was made. A primary goal of this study was to investigate the effectiveness of the various methods of modeling the vortex. The model problem restricts the interaction to that of an infinite wing with an infinite line vortex moving parallel to its leading edge. This problem provides a convenient testing ground for the various methods of modeling the vortex while retaining the essential physics of the full three-dimensional interaction. A full-potential algorithm specifically tailored to solve the blade-vortex interaction (BVI) was developed to solve this problem. The basic algorithm was modified to include the effect of a vortex passing near the airfoil. Four different methods of modeling the vortex were used: (1) the angle-of-attack methods, (2) the lifting-surface method, (3) the branch-cut method, and (4) the split-potential method. A side-by-side comparison of the four models was conducted. these comparisons included comparing generated velocity fields, a subcritical interaction, and a critical interaction. The subcritical and critical interactions are compared with experimentally generate results. The split-potential model was used to make a survey of some of the more critical parameters which affect the BVI.
Three-dimensional Vortex-body Interaction in a Viscous Fluid
Author: Jeffrey S. Marshall
Publisher:
ISBN:
Category : Fluid dynamics
Languages : en
Pages : 50
Book Description
An experimental and computational study of the impact of a vortex with a body oriented normal to the vortex axis was performed. Particular focus was placed on understanding characteristics of the secondary vorticity ejected from the body and the interaction of the secondary vorticity with the primary vortex. Since both onset of boundary layer separation and the form of the secondary vorticity structures are sensitive to variation of the velocity normal to the body axis, the effect of normal velocity on vortex-body interaction was carefully examined. The physical features of the flow evolution were categorized in terms of an impact parameter and a thickness parameter, which respectively represent ratios of velocity and length scales associated with the vortex to those associated with the flow in the absence of the vortex. Experiments were performed using a combination of laser-induced fluorescence (LIF) flow visualization and particle-image velocimetry (PIV) in a water tank to examine the form of the secondary vorticity structures with both "high" and "low" values of the impact parameter for normal vortex interaction with a circular cylinder and with a thin blade. A new type of Lagrangian vorticity method based on a tetrahedral mesh was developed and applied to compute the secondary vorticity evolution during vortex-cylinder interaction. Computations were also performed for model problems to examine in detail wrapping of a vortex loop around a columnar vortex and impulsive cutting of a columnar vortex with finite axial flow.
Publisher:
ISBN:
Category : Fluid dynamics
Languages : en
Pages : 50
Book Description
An experimental and computational study of the impact of a vortex with a body oriented normal to the vortex axis was performed. Particular focus was placed on understanding characteristics of the secondary vorticity ejected from the body and the interaction of the secondary vorticity with the primary vortex. Since both onset of boundary layer separation and the form of the secondary vorticity structures are sensitive to variation of the velocity normal to the body axis, the effect of normal velocity on vortex-body interaction was carefully examined. The physical features of the flow evolution were categorized in terms of an impact parameter and a thickness parameter, which respectively represent ratios of velocity and length scales associated with the vortex to those associated with the flow in the absence of the vortex. Experiments were performed using a combination of laser-induced fluorescence (LIF) flow visualization and particle-image velocimetry (PIV) in a water tank to examine the form of the secondary vorticity structures with both "high" and "low" values of the impact parameter for normal vortex interaction with a circular cylinder and with a thin blade. A new type of Lagrangian vorticity method based on a tetrahedral mesh was developed and applied to compute the secondary vorticity evolution during vortex-cylinder interaction. Computations were also performed for model problems to examine in detail wrapping of a vortex loop around a columnar vortex and impulsive cutting of a columnar vortex with finite axial flow.
New Technique for Experimental Generation of Two-dimensional Blade-vortex Interaction at Low Reynolds Numbers
Author: Earl R. Booth
Publisher:
ISBN:
Category : Flow visualization
Languages : en
Pages : 32
Book Description
Publisher:
ISBN:
Category : Flow visualization
Languages : en
Pages : 32
Book Description
New Techniques for Experimental Generation of Two-dimensional Blade-vortex Interaction at Low Reynolds Numbers
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 32
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 32
Book Description
Scientific and Technical Aerospace Reports
Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 704
Book Description
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 704
Book Description
NASA Scientific and Technical Publications
Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 188
Book Description
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 188
Book Description
Research in Progress
Author:
Publisher:
ISBN:
Category : Military research
Languages : en
Pages : 424
Book Description
Publisher:
ISBN:
Category : Military research
Languages : en
Pages : 424
Book Description
NASA Technical Paper
Author:
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 32
Book Description
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 32
Book Description
Monthly Catalogue, United States Public Documents
Author:
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 1644
Book Description
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 1644
Book Description