Author: Rajendran Rajasekar
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
Experimental Investigation of Flow Separation at a Swept Edge
Author: Rajendran Rajasekar
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
EXPERIMENTAL INVESTIGATION OF FLOW SEPARATION FROM RIGID WALLS WITH SALIENT EDGES.
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
This thesis presents the experimental results on the formation of flow separation from a rigid wall with a salient edge. In the case of automotive vehicles or aircrafts with rear cargo compartment doors, such salient edges are at the origin of separated wake flows resulting in increased drag and other disturbing effects. Recent studies of Ahmed et al. (1984) on simplified geometries showed the strong influence of the slant angle on the flow separations. In this study, the geometry is further simplified to examine the flow separation under two-dimensional conditions. The experimental configuration consists of a fixed horizontal front panel and an attached rear panel with variable slant angle. The experiments were carried out in a low speed water channel to analyze the flow structure by flow visualization techniques. The hydrogen bubble technique nd PIV measurements are used to obtain both qualitative and quantitative information on the flow structure. The electrolytic precipitation technique is used to analyze the flow separation in more detail. The slant angle varied between 0 and 35 degrees while the Reynolds numbers of the model was fixed to 24800 and 50500. As a function of slant angle and Reynolds number, two different types of flow separation were observed: boundary layer separation due to adverse pressure gradient and the so called “inertial separation” at the edge singularity. Future strategies to control the formation of the wake flow highly depend on the very different flow structure of these two types of separation.
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
This thesis presents the experimental results on the formation of flow separation from a rigid wall with a salient edge. In the case of automotive vehicles or aircrafts with rear cargo compartment doors, such salient edges are at the origin of separated wake flows resulting in increased drag and other disturbing effects. Recent studies of Ahmed et al. (1984) on simplified geometries showed the strong influence of the slant angle on the flow separations. In this study, the geometry is further simplified to examine the flow separation under two-dimensional conditions. The experimental configuration consists of a fixed horizontal front panel and an attached rear panel with variable slant angle. The experiments were carried out in a low speed water channel to analyze the flow structure by flow visualization techniques. The hydrogen bubble technique nd PIV measurements are used to obtain both qualitative and quantitative information on the flow structure. The electrolytic precipitation technique is used to analyze the flow separation in more detail. The slant angle varied between 0 and 35 degrees while the Reynolds numbers of the model was fixed to 24800 and 50500. As a function of slant angle and Reynolds number, two different types of flow separation were observed: boundary layer separation due to adverse pressure gradient and the so called “inertial separation” at the edge singularity. Future strategies to control the formation of the wake flow highly depend on the very different flow structure of these two types of separation.
Experimental Investigation of a Fin-cone Interference Flow Field at Mach 5
Author: Gillerlain, Jr. (Joseph D.)
Publisher:
ISBN:
Category : Aerodynamic heating
Languages : en
Pages : 86
Book Description
The general purpose of this investigation was to study the separated flow field associated with a fin-body juncture. Specific objectives included: (a) determining the severity and extent of aerodynamic heating, (b) providing flow visualization results to illustrate the flow structure, and (c) obtaining a data base of heat-transfer and surface-pressure measurements upon which to develop future analytical relations to predict peak interference heating levels. Tests were conducted at Mach 5 over a unit Reynolds number range of 4.5 to 26 million per foot. A fin-cone model was used. The data consist of surface- pressure distributions, heat-transfer measurements using the phase-change paint technique, and schlieren and oil-flow photographs. Results are presented for several fin-cone geometries to include fin sweep and fin-cone gap. Where possible, comparisons are made with fin-flat-plate data.
Publisher:
ISBN:
Category : Aerodynamic heating
Languages : en
Pages : 86
Book Description
The general purpose of this investigation was to study the separated flow field associated with a fin-body juncture. Specific objectives included: (a) determining the severity and extent of aerodynamic heating, (b) providing flow visualization results to illustrate the flow structure, and (c) obtaining a data base of heat-transfer and surface-pressure measurements upon which to develop future analytical relations to predict peak interference heating levels. Tests were conducted at Mach 5 over a unit Reynolds number range of 4.5 to 26 million per foot. A fin-cone model was used. The data consist of surface- pressure distributions, heat-transfer measurements using the phase-change paint technique, and schlieren and oil-flow photographs. Results are presented for several fin-cone geometries to include fin sweep and fin-cone gap. Where possible, comparisons are made with fin-flat-plate data.
Theoretical and Experimental Investigation of the Subsonic-flow Fields Beneath Swept and Unswept Wings with Tails of Vortex-induced Velocities
Author: William J. Alford
Publisher:
ISBN:
Category : Air flow
Languages : en
Pages : 100
Book Description
The flow-field characteristics beneath swept and unswept wings as determined by potential-flow theory are compared with the experimentally determined flow fields beneath swept and unswept wing-fuselage combinations. The potential-flow theory utilized considered both the spanwise and chordwise distributions of vorticity as well as the wing-thickness effects. The perturbation velocities induced by a unit horseshoe vortex are included in tabular form.
Publisher:
ISBN:
Category : Air flow
Languages : en
Pages : 100
Book Description
The flow-field characteristics beneath swept and unswept wings as determined by potential-flow theory are compared with the experimentally determined flow fields beneath swept and unswept wing-fuselage combinations. The potential-flow theory utilized considered both the spanwise and chordwise distributions of vorticity as well as the wing-thickness effects. The perturbation velocities induced by a unit horseshoe vortex are included in tabular form.
NASA Technical Paper
Author:
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Category : Astronautics
Languages : en
Pages : 608
Book Description
Publisher:
ISBN:
Category : Astronautics
Languages : en
Pages : 608
Book Description
Reportnr.: ISL CO 208 86
Author: Claude Berner
Publisher:
ISBN:
Category :
Languages : en
Pages : 16
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 16
Book Description
An Experimental Investigation of Smooth-body Flow Separation
Author: Daniel J. Simmons
Publisher:
ISBN:
Category :
Languages : en
Pages : 339
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 339
Book Description
An Experimental Investigation of the Subcritical and Supercritical Flow about a Swept Semispan Wing
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 258
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 258
Book Description
Experimental Investigation of Flow Separation Associated with a Step Or a Groove
Author: Itiro Tani
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages :
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