Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 14 of 14 for “"corner separation"”.
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Understanding Unsteady Corner Separation Within Wing-Body Junction Flows
… flow field. This thesis focused on the unsteady corner separation that develops at the trailing edge of this wing-body junction under certain conditions. A NACA 0015 wing mounted on a flat plate at an angle of attack of 13°was used as the model junction flow field. The wing had an aspect ratio of …
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Turbulence Modelling for Complex Flows in Turbomachinery
… features of turbomachinery flows, that is, the corner separation flow often found in axial compressor stators, is selected as the research object. Based on the understanding of the underlying physics of this complex flow, the RANS turbulence closure models and a hybrid RANS-LES method are …
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Effective methods of controlling a junction vortex system in an incompressible, three-dimensional, turbulent flow
… which is believed to be identified with the corner separation at the junction near the trailing edge. Mean flow measurements of the flow field around and in the wake of a NACA 0020 body with more slender noses were acquired. The results indicate that the more slender nose generated a weaker …
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Corner effects for oblique shock wave/turbulent boundary layer interactions in rectangular channels
… SBLI) both on the bottom wall and in the corner formed by the intersection of the floor with the side-walls. In such a scenario, shock-induced separation is often seen in each of the streamwise corners, resulting in a highly three-dimensional flow field in the near-wall region. To examine …
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The Unsteady Topology of Corner Separations
… axial compressor is throttled three-dimensional separations develop in the corners between the blades and annulus endwall. Surprisingly, little is understood about the unsteady topology of these separations. One of the problems with studying corner separations is that it is often difficult to …
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Supersonic Corner Flows in Rectangular Channels
… due to the presence of sidewalls and associated corner boundary layers. The main effect is on the local separation of these corner regions, which then affects the wider flow field. Successful prediction of the overall flow therefore relies on the corner separation to be determined accurately. …
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Incorporation of High-Fidelity Flow Field Information into Preliminary Design of Multi-Stage Axial Compressors
… growth, spanwise mixing, and endwall-corner separation. The methodology includes the effects of changes in radial non-uniformity and in blade geometry on the axisymmetric flow field. The approach can supersede current throughflow methods, increasing the fidelity of preliminary design. …
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Reynolds number effects on the aerodynamics of compact axial compressors
… to the rotor loss was an unexpected hub separation that increased in size as $Re$ was reduced. At higher $Re$, the major loss sources were the rotor tip leakage, the stator wake and the stator hub separation. The results indicate that an improved stator design that accounts for the …
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Sidewall effects in compression corner shock-wave/boundary-layer interactions
Streamwise corners are a common three-dimensional geometric feature encountered in supersonic flows, appearing in wing-body junctions, in rectangular cross sectioned inlets and research wind tunnels. When a shock wave boundary layer interaction (SBLI) occurs in a rectangular cross sectioned duct, …
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An experimental study on the effects of blade row interactions on aerodynamic loss mechanisms in a multistage compressor
… in the compressor by highlighting stator corner separations and endwall flow patterns. Effects of loading condition, rotor tip clearance height, and stator wake and rotor tip leakage interactions are shown with this technique. ^ Vane clocking effects on compressor performance were …
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Towards Predictive Eddy Resolving Simulations for Gas Turbine Compressors
… to prevent dispersion. On the suction surface, separation induced transition occurs. The flow here is seen to be relatively insensitive to numerical smoothing and the choice of SGS model, as long as the Smagorinsky-Lilly SGS model is not used. These findings are encouraging, as they show that, …
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Three-dimensional Mechanisms in Compressor Flows
… limits design by not considering the effect, on separation and loss, of the pressure gradient on the surface of the blade perpendicular to the meridional direction, here known as the transverse pressure gradient. The results of this thesis are contained within four chapters. The first two …
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The Design of Aspirated Compressor Bleed
… the secondary flows, affecting the onset of open corner separation formation. When the aspiration hole array is centred at 50% blade chord, the separation formation is suppressed to 6° higher stator incidence. Furthermore, doubling the suction on lower 50% of blade span, through altering the …
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Active control of massively separated high-speed/base flows with electric arc plasma actuators
… electric-arc plasma discharges near the base corner separation point. The control authority of electric arc plasma actuators on a supersonic axisymmetric base flow was evaluated for several actuator geometries, frequencies, forcing modes, duty cycles/on-times, and currents. Initially, an …