1988 Fiscal Year Final Research Report Summary
Development for a Flame-Propagation Model by Use of Finite-Difference Methods
| Project/Area Number |
62550132
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Fluid engineering
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| Research Institution | Tottori University |
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Principal Investigator |
TAKANO Yasunari Faculty of Engineering, Tottori University, 工学部, 助教授 (00089111)
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| Project Period (FY) |
1987 – 1988
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| Keywords | Flame Propagation / Combustion / Gasdynamics / Reactive Gasdynamics / Finite Difference Method / 数値シュミレーション |
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| Research Abstract |
A flame-propagation finite-difference model has been proposed to simulate time-dependent multidimensinal compressible flows generated by a flame in premixed combustible gas. In the model, a detailed structure of the flame is disregarded and the flame is treated as a deflagration front. Flame-induced gasdynamic flowfields are calculated when a flame-burning speed and a combustion heat are given as parameters of the model to specify the deflagration relation. The present model is a flame-capturing approach in which artificial combustion reaction is considered to occur in an interface (deflagration front) between unburnt and burnt gas. The artificial reaction term has been heurisically derived so as to emphasize that the deflagration front propagates in a direction perpendicular to itself at the given flame-burning speed. The inviscid gasdynamic equations coupled with the mass conservation of the burnt gas with the artificial reaction term are numerically solved by using the Richitmyer-FCT scheme. Comparisons of the one-dimensional flame propagation between the numerical results and analytical solutions show that the model correctly predicts jumps of the fluid properties across flames obeying the deflagration relation. Calculations have been conducted for spherically symmetric flames propagating in a spherical vessel filled with stoichiometric methane/air and the numerical results are compared with analytical results of a flame-surface model. Agreements are shown to be fairly well between the computational and the analytical results. Simulations have been also carried out for a flame propagating in a cylindrical vessel. The formation of the tulip shape, observed in experiments, is successfully simulated for a burning speed 10 times as much as real one. R ations are examined and reasons are explained why the tulip-formation takes place.
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