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 “"Displacement speed"”.
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Propagation of spherically expanding premixed flames
… at nearly isobaric conditions and the flame displacement speed eventually reaches a constant value whereas in the confined case there is pressure buildup which affects the flame displacement speed which increases as the flame grows larger. In the confined case, the evolution of the flame with …
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Turbulent partially premixed combustion: DNS analysis and RANS simulation
… the effects of partial premixing on the displacement speed of iso-scalar surface and its correlation with the surface curvature are explored using DNS data. The scalar gradient alignment characteristics change from aligning with the most compressive strain to aligning with the most …
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Application of Crossed-Plane Tomography and Stereo Particle Image Velocimetry for Three-Dimensional Analysis of Premixed Turbulent Flames
… dimensional reactant velocities, and flamelet displacement speeds in a turbulent V-flame. This technique was also used to measure in-plane flamelet curvature in laboratory V-flames. The distribution of flamelet orientations is found to have a simple universal form depending on a single …
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Isosurface Interactions Within Turbulent Premixed Hydrogen and Hydrocarbon Flames
… equations for Surface Density Function (SDF) and displacement speed in the vicinity of a critical point and Direct Numerical Simulation (DNS) is used to validate the theoretical results. In particular, the formation of isolated pockets of reactants or products is associated with flame pinch--off …
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Experimental investigations on gas explosions in partially confined regions
… the basis for flame propagation, local flame displacement speed probability density functions (pdfs), mean flame velocity and explosion pressure. The second investigation of the study involved the flame interaction with multiple bars within chambers of different L/D ratios. The results …
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Fundamental studies of flame propagation in lean-burn natural gas engines
… with mixing layer thickness and laminar flame speed and thickness.</p> <p>Subsequent work focuses on turbulent flame propagation in lean homogeneous mixtures by employing direct numerical simulations (DNS) under conditions that are relevant to lean-burn engines. Attention is specifically …
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Development of a multi-scale projection method with immersed boundaries for chemically reactive flows and its application to examine flame stabilization and blow-off mechanisms
… that a flame was stable when (1) the local flame displacement speed was equal to the flow speed (static stability), and (2) the gradient of the flame displacement speed normal to its surface was higher than the gradient of the flow speed along the same direction (dynamic stability). As the …
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DNS of inhomogeneous reactants premixed combustion
… 68 steps. The flame surface density (FSD) and displacement speed S_d have been used as the framework to analyse the inhomogeneous reactants premixed flame. The flames are characterised by an isosurface of reaction progress variable. The unsteady flames are compared to the steady laminar …
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Relation between flame speed and stretch for a premixed flame in a stagnation point flow
The student, Midhun Joy, submitted this Thesis for approval on 2017-12-11 at 14:52.
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Studies of premixed turbulent flames under flamelet assumptions
… expanding flames). Turbulent consumption speeds s_c were provided at any arbitrary isocontour of ¯c, and connected with local displacement speeds sT in both Bunsen and spherical expanding flames. sc,0 = m˙ /(ρ_uA0) was found to be equal to sT,0 (displacement speed at the leading edge of …