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 12 of 12 for “"Global Instability"”.
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Global stability and control of swirling jets and flames
… hydrodynamic oscillations, also known as global hydrodynamic instability. Direct numerical simulation (DNS) of the Navier--Stokes equations in the low Mach number limit is used to obtain a steady base flow, and the most unstable direct and adjoint global modes. These are combined, using a …
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Sensitivity analysis of low-density jets and flames
… is used to calculate direct-linear and adjoint global modes for axisymmetric low-density jets and lifted jet diffusion flames. The adjoint global modes provide a map of the most sensitive locations to open-loop external forcing and heating. For the jet flows considered here, the most sensitive …
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Dynamics Of Internal Solitary Wave And Bottom Boundary Interaction
… which are associated with reflection, convective instability and boundary layer separation, respectively. Over mild slopes (S≤0.05), nonlinearity varies gradually and the wave fissions into a train of waves of elevation after it passes through the turning point where solitary waves reverse …
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Static and dynamic stability analysis of a truss model
… is found that the truss model shows a local and global failure for a certain class of loading. The magnitudes of the critical loads for local instability are significantly less than the magnitudes of the critical loads for global instability when the loading is symmetric or near symmetric. It is …
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Regional Resilience: Are recessionary shocks persistent or transitory?
… which is characterised by a period of severe global instability resulting from unprecedented economic shocks. Martin et al. (2016) note that in economic geography resilience describes regions’ reactions to, and recovery from, negative economic shocks, based on a concept which has been widely …
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Experimental and analytical investigation of localization and post-peak behavior of steel members in tension
… states are associated with local or global instability such as local buckling, tension necking, and fracture. Several methods have been developed to simulate such extreme limit states such as fiber models, hinge models, nonlocal models, and finite element analysis (FEA). However, …
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Assessing levels of reliability for design criteria for hurricane and storm damage risk reduction structures
… for pile-founded structures subject to global instability. This dissertation presents a methodology for quantifying the reliability of pile-founded structures that can be applied to hurricane risk reduction structures or more broadly to other types of pile-founded structures. The …
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Plasmas of Arbitrary Neutrality
… ≈ 0.01 to 0.8 are identified as an ion resonant instability propagating close to the E × B velocity of the plasma. The experiments also show that these oscillations present a poloidal mode number m = 1, and a toroidal number n = 0, which is identical to the spatial structure of the diocotron …
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Molecular Mechanics Simulations of Instabilities in 3D Deformations of Gold Nanospecimens
… tight-binding (TB) potential to study local and global instabilities in initially defect-free finite specimens of gold crystals deformed in shear, simple shear, tension/compression, simple tension/compression, and triaxial tension/compression. The criteria used to delineate local instabilities in …
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Seismic stability of buckling-restrained braced frames
… susceptible to concentrations of story drift and global instability triggered by P-Δ effects. Due to the use of simplistic methods that are based on elastic stability, current code design provisions do not address seismic stability rigorously and do not consider the particular inelastic response …
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Forcing of globally unstable jets and flames
… as a premixed bunsen flame, are hydrodynamically globally stable. They respond only at the forcing frequency. Other flames, such as a jet diffusion flame, are hydrodynamically globally unstable. They oscillate at their own natural frequencies and are often assumed to be insensitive to …
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Modeling of shock boundary layer interactions and stability analysis using particle approaches
… between two contact surfaces. A Kelvin-Helmholtz instability arising at the shear layer results in an unsteady flow for the highest Reynolds number. These findings suggest that consideration of experimental measurement times is important when it comes to deter- mining the steady state surface …