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Weeratunga, Sisira Kumara 2014-12-16T19:12:37Z 2014-12-16T19:12:37Z 10000-01-01 1986 1986 Mixtures of hydrogen and air, when confined to a standard flammability tube, exhibit a remarkable flame structure in the neighborhood of the lean limit. The subject of this dissertation is the investigation of this fine structure, referred to as "flame bubbles", brought about by cellular type instability. We consider the numerical simulation of steady, buoyancy induced motion of an isolated hydrogen flame bubble, with the intention of gaining an understanding of the qualitative features of the associated flow field. The mathematical model is derived from thin flame sheet approximation based on high activation energy asymptotics. This leads to the numerical solution of the variable density Navier-Stokes equations and the energy equation in an axisymmetric geometry. Use of the finite difference discretization gives rise to a system of non-linear equations, which is solved using the Newton-Raphson method. The large sparse system of non-symmetric linear equations corresponding to the Jacobian matrix is then solved using direct as well as iterative schemes. Made available in DSpace on 2014-12-16T19:12:37Z (GMT). No. of bitstreams: 1 8701647.pdf: 7646197 bytes, checksum: 21e3bb90f34a7ebb933a4e271489bd31 (MD5) Previous issue date: 1986 Embargo set by: Seth Robbins for item 71856 Lift date: Forever Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs U of I Only 288 p. Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1986. http://hdl.handle.net/2142/71690 (UMI)AAI8701647 Engineering, Mechanical Numerical Solution of Buoyancy Induced Motion of a Hydrogen Flame Bubble (Combustion, Convection) text Theoretical and Applied Mechanics Theoretical and Applied Mechanics University of Illinois at Urbana-Champaign Dissertation Ph.D.