Flames, Flows and Their Interactions

层流火焰在一定条件下， 不稳定，导致褶皱或波纹状结构。 是 显然，不稳定的一般特征是 与底层流体流动密切相关， 热量从火焰前端转移出去 分层 混合物存在于许多燃烧环境中， 弯曲的和可能不稳定的传播火焰前锋。 的 建议的研究是针对一个基本的 了解层流的行为和反应， 预混火焰在流场中的这种不均匀性。 液滴蒸发和燃烧也将是 研究了 将使用的技术是渐近 和扰动方法，并辅以数值 计算，与观察到的物理结果相比， 现象。 对系统中燃烧行为的理解 像发动机和熔炉这样复杂的设备， 一个非常简化的描述分析模型， 分离一个或两个控制物理参数。 这 理论研究将试图扩大应用 预混火焰的渐近和扰动技术 在非均匀混合物中传播，目的是 深入了解应变率、火焰前锋 曲率、涡度、质量扩散和热传递 火焰稳定性

Laminar flames can, under certain conditions, be inherently unstable, leading to wrinkled or corrugated structures. It is clear that the general character of the instability is intimately tied to the underlying fluid flow and by the extent of heat transfer away from the flame front. Stratified mixtures exist in many combustion environments, creating a curved and possibly unsteady propagating flame front. The proposed research is directed towards a fundamental understanding of the behavior and response of a laminar, premixed flame to such non-uniformities in the flow field. Droplet vaporization and combustion will also be investigated. The techniques to be used are the asymptotic and perturbation methods supplemented by numerical calculations, with the results compared to observed physical phenomena. One's understanding of the behavior of combustion in systems as complex as engines and furnaces is often enhanced by an analytical model of a much simplified description which isolates one or two controlling physical parameters. This theoretical study will attempt to stretch the application of asymptotic and perturbation techniques to premixed flames propagating in non-uniform mixtures, with the objective of gaining insight into the effects of strain rate, flame front curvature, vorticity, mass diffusion, and heat transfer on the flame stability.