scholarly journals Three-Component Force Measurements for Scramjet Engines 2) Effects of External Flow and Boundary Layer Ingestion

2003 ◽  
Vol 51 (592) ◽  
pp. 252-259 ◽  
Author(s):  
Tohru Mitani ◽  
Yuichi Tarukawa ◽  
Muneo Izumikawa ◽  
Syuichi Watanabe ◽  
Takashi Shimura
Keyword(s):  
Boundary Layer ◽  
External Flow ◽  
Force Measurements ◽  
Scramjet Engines ◽  
Component Force

Boundary-Layer Flow Between the Attachment Lines on a Flat Plate Delta Wing at Incidence

1962 ◽  
Vol 13 (1) ◽  
pp. 1-16
Author(s):  
J. C. Cooke
Keyword(s):  
Boundary Layer ◽  
Delta Wing ◽  
Three Dimensional ◽  
External Flow ◽  
Two Dimensional ◽  
Conical Flow ◽  
Slender Body Theory ◽  
Layer Flow ◽  
Body Theory ◽  
Transition Fronts

SummaryA three-dimensional laminar-boundary-layer calculation is carried out over the area concerned. The external flow is simplified, being calculated by slender-body theory assuming conical flow, with two point vortices above the wing, their positions and strength being determined by experiment. Attempts are made to draw transition fronts both for two-dimensional and sweep instability from this calculation. The combination of these gives fronts similar to those observed in some experiments. Because there is little or no pressure gradient over the area in question it is suggested that it is a region where distributed suction might usefully be applied in order to maintain laminar flow and reduce drag.

Correction: Studies on 2D and 3D Boundary layer Blockage and External Flow Choking at Moving Wing in Ground Effect

2018 ◽  
Author(s):  
VR Sanal Kumar ◽  
Vignesh Saravanan ◽  
Vivek Srinivasan ◽  
Ganesh Shankar S ◽  
Sivabalan Mani ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Ground Effect ◽  
External Flow ◽  
Flow Choking ◽  
2D And 3D ◽  
Wing In Ground Effect

Instability in a viscous flow driven by streamwise vortices

2001 ◽  
Vol 432 ◽  
pp. 127-166 ◽  
Author(s):  
K. W. BRINCKMAN ◽  
J. D. A. WALKER
Keyword(s):  
Boundary Layer ◽  
Numerical Solutions ◽  
Three Dimensional ◽  
Wall Layer ◽  
External Flow ◽  
Three Dimensional Flow ◽  
Dimensional Flow ◽  
Wall Flow ◽  
Turbulent Wall ◽  
Near Wall

Unsteady separation processes at large finite, Reynolds number, Re, are considered, as well as the possible relation to existing descriptions of boundary-layer separation in the limit Re → ∞. The model problem is a fundamental vortex-driven three-dimensional flow, believed to be relevant to bursting near the wall in a turbulent boundary layer. Bursting is known to be associated with streamwise vortex motion, but the vortex/wall interactions that drive the near-wall flow toward breakdown have not yet been fully identified. Here, a simulation of symmetric counter-rotating vortices is used to assess the influence of sustained pumping action on the development of a viscous wall layer. The calculated solutions describe a three-dimensional flow at finite Re that is independent of the streamwise coordinate and consists of a crossflow plane motion, with a developing streamwise flow. The unsteady problem is constructed to mimic a typical cycle in turbulent wall layers and numerical solutions are obtained over a range of Re. Recirculating eddies develop rapidly in the near-wall flow, but these eddies are eventually bisected by alleyways which open up from the external flow region to the wall. At sufficiently high Re, an oscillation was found to develop in the streamwise vorticity field near the alleyways with a concurrent evolution of a local spiky behaviour in the wall shear. Above a critical value of Re, the oscillation grows rapidly in amplitude and eventually penetrates the external flow field, suggesting the onset of an unstable wall-layer breakdown. Local zones of severely retarded streamwise velocity are computed which are reminiscent of the low-speed streaks commonly observed in turbulent boundary layers. A number of other features also bear a resemblance to observed coherent structure in the turbulent wall layer.

Effect of Ingested Boundary Layer on Scramjet Engines' Thrust and Combustion Characteristics

2003 ◽  
Author(s):  
Tetsuo Hiraiwa ◽  
Takeshi Kanda ◽  
Masatoshi Kodera ◽  
Toshihito Saito ◽  
Kan Kobayashi ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Combustion Characteristics ◽  
Scramjet Engines
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