The Dynamics of Combustion Systems With Swirl and Vortex Breakdown

摘要-9904327 ZVI RUSAK 这项工作的目标是开发一个实验验证模型的燃烧状态与旋流的动态，并提供一个物理机制，导致贫油，预混燃烧系统的不稳定性的理解。 分析结合了联合收割机经典的渐近方法与现代工具，从功能分析，动力系统理论，非线性偏微分方程理论。 重点是燃烧和流动条件下可能发生的分叉和小或大幅度的不稳定性可能演变。 边界条件取自实验观察。 进行了大量的数值计算，特别是系统的远离分岔行为。 理论和数值计算结果进行了比较，从路易斯安那州立大学的模型和代码验证的数据，并从预测的不稳定性或瞬变，影响燃烧process.Instabilities开发在贫，预混燃烧系统与旋流严重的设计局限性，在现代，低排放系统，特别是当涡破裂被利用来稳定火焰和提高燃烧效率。

ABSTRACTCTS-9904327 ZVI RUSAK The goal of this effort is the development of an experimentally verified model for the dynamics of combustion states with swirling flows and to provide an understanding of the physical mechanisms leading to instabilities in lean, premixed combustion systems. Analyses combine classical asymptotic approaches with modern tools from functional analysis, dynamical system theory, and the theory of nonlinear partial differential equations. Emphasis is on combustion and flow conditions for which bifurcations may occur and where small- or large-amplitude instabilities may evolve. Boundary conditions are taken from experimental observations. Extensive numerical computations are conducted, in particular of the far-from bifurcation behavior of the system. Theoretical and numerical results are compared with data from Louisiana State University for model and code validation, and from prediction of instabilities or transients that affect the combustion process.Instabilities that develop in lean, premixed combustion systems with swirl present severe design limitations in modern, low-emission systems, especially when vortex breakdown is exploited to stabilize the flame and enhance combustion efficiency.