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Showing 1 to 20 of 46 for “"Boundary layer separation"”.
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Turbulent boundary layer separation and its driving factors
Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2025-03-28 without embargo terms
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Boundary Layer Separation Control on a Salient Back-facing Ramp
… devices on a salient edge where the laminar boundary layer separation is two-dimensional. Three geometries of serrations: a sharp delta, a double delta and a divergent delta are examined on 15° and 30° deflected, backward-facing ramps. Parameterizing the device spacing and the …
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Turbulent Boundary Layer Separation From Smooth-Convex Surfaces in Supersonic Two-Dimensional Flow
Made available in DSpace on 2014-12-09T17:13:30Z (GMT). No. of bitstreams: 1 6406179.pdf: 3432564 bytes, checksum: 27bb187614c4b5b067de4e7bf2c82811 (MD5) Previous issue date: 1963
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An experimental investigation of the use of air jet vortex generators to control shock induced boundary layer separation
… their effectiveness in delaying shock induced boundary layer separation was not as good as conventional vane type generators. Recent low speed wind tunnel tests carried out at City University indicated that the strength of the vortex could be increased considerably by using rectangular jet …
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Dynamics Of Internal Solitary Wave And Bottom Boundary Interaction
… of depression shoaling upon a uniformly sloping boundary in a smoothed two-layer density field was investigated using high-resolution two-dimensional simulations. The simulations were performed for a wide range of boundary slopes S∈[0.01,0.3] and wave slopes. Over steep slopes (S≥0.1), three …
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Open-loop and closed-loop trailing-edge separation control on a natural laminar flow airfoil
… the chord near the trailing edge results in the separation of the flow from the airfoil surface at the off-design conditions. The goal of this study was to control boundary-layer separation across the trailing-edge region of the airfoil in an effort to improve the performance beyond the designed …
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Numerical studies of Newtonian and viscoelastic fluids
… approach is also used to demonstrate that the boundary layer separation on the upper surface of the airfoil can be suppressed by placing injection and suction regions on the upper surface. The simulations are performed for Re [less than or equal too] 500 and angle of attack up to 40 . Analysis …
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Creation of a Trimmed Powered Aerodynamic Database for a Generic Hypersonic Vehicle
… The viscous solutions contain effects such as boundary layer separation which had a pronounced effect on the computed axial force. In all cases, the viscous solutions predicted a lower thrust than the inviscid solutions, mainly due to the presence of viscous shear stresses. Experimental data …
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Experimental Investigation of Liquid and Gas Fueled Flames Towards the Development of a Burning Rate Emulator (BRE) for Microgravity Applications
… Steady flames were obtained, and ranged from boundary layer flames to plume-type burning. Maximum burning rate per unit area was recorded at an upward inclination of 30º. Mass flux decreased with increasing wick length for all orientations. Dimensionless correlations, using a Rayleigh number …
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Viscous-inviscid interactions of dense gases
… and oblique compression waves with a laminar boundary layer on an adiabatic flat plate is analyzed by solving the Navier-Stokes equations in conservation-law form numerically. The numerical scheme is based on the Beam and Warming’s implicit method with approximate factorization. We examine the …
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Space--Time Computation of a Ringsail Parachute With Model Thickness
… the thickness, we expect to represent the boundary layer separation better. Thanks to the Space–Time Slip Interface (ST-SI) method and recent advances in the ST-Isogeometric Analysis (ST-IGA), we can greatly reduce the number of elements. The ST-SI method, at an interface between two mesh …
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Implementation of travelling waves on lifting surface for drag reduction
… the drag force. At moderate angles of attack, boundary layer separation begins near the trailing edge, and moves up to the leading edge as the angle increases. Such a phenomenon raises the form drag significantly, and a method of pushing the separation point back towards the trailing edge could …
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Optimization of Flow Quality In the Test Section of The 30-Inch x 40- Inch Subsonic Tunnel
… were installed in front of the inlet to minimize boundary layer separation. Furthermore, a screen was attached to the inlet to help reduce the turbulence level. By combining all the configurations the flow reached a uniform distribution for more than ninety percent of the cross sectional area, …
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The aerodynamic response of airborne discs
… experiment was a tuft test to describe the boundary layer, done at different velocities and angles of attack. The spinning disc experiment utilized smoke to visualize the flow around the disc and ascertain the effects of spin on vorticity and boundary layer separation. Results showed that …
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Flow separation control with rotating cylinders
… and reduce efficiency. Applying active flow separation control to ocean vehicles would reduce resistance during maneuvers and thereby improve maneuvering performance. In this thesis I discuss experiments in active separation control in a simpler, but still relevant, two-dimensional flow past …
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Heat Transfer and Flow Characteristics on the Rotor Tip and Endwall Platform Regions in a Transonic Turbine Cascade
… in regions with local flow reattachment and new-boundary layer formation. Conversely, the lowest heat transfer occurs in regions with boundary layer thickening and separation/lift-off flow. However, boundary layer separation results in additional secondary flow vortices, such as the squealer …
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Vortex flow around the bases of obstacles
… of the horseshoe vortex systems caused by boundary layer separation upstream of obstacles mounted on a wall. Flow visualization enabled these vortex systems to be described in detail for both laminar and turbulent flow upstream of the obstacles, for flow velocities between 0.3 ms-1 and 25 …
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Distant hemodynamic impact of local geometric alterations in the arterial tree
… using both qualitative and quantitative tools. Boundary layer separation and vascular resistance in one location of the arterial tree varied with geometrical alterations in another. In-vivo models were developed that allowed investigation of the effect of side branch occlusion or dilation on the …
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Ram-jet combustion based on shock/flame interaction
… bleed mode (peripheral or axial). The onset of boundary layer separation due to the adverse pressure gradient encountered when the base pressure is high appears to limit the useful addition of wake combustion. Finally, it is demonstrated that the base pressure, with and without combustion, is …
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An Investigation of Dolphin-Groove Inspired Surface Patterning on Flow Control
A problem in many flow applications is boundary layer separation; this study investigates the passive separation control mechanism that could result from the micro-grooves found on dolphin skin (Tursiops truncates). A water tunnel was used to study a turbulent boundary layer over rigid 3D printed …
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