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 10 of 10 for “"Shear layer instability"”.
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Effect of roughness element on the stability of boundary layers
The instability of flows around hump and dip imperfections is investigated. The mean flow is calculated using interacting boundary layers, thereby accounting for viscous/inviscid interaction and separation bubbles. Then, the two-dimensional linear instability of this flow is analyzed, and the …
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The aeroacoustics response and shear layer dynamics of confined cavities subject to low Mach number turbulent flow
… phenomenon attributed to interaction between the instability of the shear layer and the acoustic modes of a given system. This thesis experimentally investigates the aeroacoustics response of cylindrical cavities having aspect ratios of h/L = 0.5, 1, and 1.5, where h is the cavity depth and L is …
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Spatiotemporal Signatures of Elastoinertial Turbulence
… quiescent water or polymer solution. In a free shear layer, fluid elasticity has a dichotomous effect on jet stability depending on its relative magnitude, creating two distinct regimes in which elastic effects can either destabilize or stabilize the jet. For small levels of elasticity an …
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Flow characteristics and acoustic resonance excitation of finned cylinders in cross-flow
… of the non-uniform fins to control the shear layer instability in the cylinders’ gap, which is the dominant excitation source for pre-coincidence acoustic resonance.
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A numerical investigation of self-sustained cavity flow oscillations
… the effect of the turbulent viscous sub-layer using the Integration-to-the-wall boundary condition. The results confirmed that the shear layer instability reduced gradually from Mach 1.5 to 3.5. An improvement in SPL prediction was achieved. Dominant modes were also correctly …
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Effect of suction and cooling on the stability of subsonic and supersonic boundary layers
… show that, whereas cooling decreases the viscous instability, it increases the shear-layer instability and hence it increases the growth rates in the separation region. The coexistence of more than one instability mechanism makes a certain degree of wall cooling most effective. For the Mach …
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Seeking Understanding of Acoustics and Spray Character in a Three-Stream Pulsating Transonic Airblast Injector
… systems (atomization energy is sourced in local shear layer instability development), however, a state-of-the-art hybrid model (newly implemented for this effort) appeared to be necessary to capture the resulting droplet scales. Lastly, droplet size and characteristic flow length scale …
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Numerical simulations of supercritical water-hydrocarbon mixing in a 3-D cylindrical tee mixer
… (Tw,in = 1000K, Td,in = 700K), the water-HC shear layer becomes unstable and rolls up downstream of 5 diameter lengths from the mixing joint. The onset of instability in the shear layer also triggers the stretching and breakdown of the hydrocarbon jet CVP leading to a significant enhancement …
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Effect of self-excited acoustic perturbations on flow characteristics around rectangular cylinders with varied geometrical aspects
… in the dynamic lift force and alteration in shear layer dynamics, which subsequently impacts the shedding pattern. The study reveals that modifying the shape of the upstream edges to be rounded can alter the shedding pattern and decrease dynamic the loading, whereas alterations to the …
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The study and control of wall bounded flows : El estudio y control de flujos de pared
… code is developed to be able to study boundary layer flows, which is described in the second part. This development is necessary since the code used for the channel simulations cannot simulate boundary layers. The goal was to develop a fourth-order, high resolution numerical scheme to simulate …