Shear layer flame stabilization sensitivities in a swirling flow

Sidewall boundary layer instabilities in confined swirling flow †

We examine enclosed swirling transitional and turbulent flows in a cylindrical vessel, driven by a single rotating endwall. The cylinder height:radius ratio H/R = 1 was chosen explicitly to preclude the possibility of vortex breakdown on the cylinder axis, thus concentrating attention on the behaviour of the cylindrical sidewall boundary layers. Over a range of Reynolds numbers above Re = ΩR2/ν...

Flame Stabilization Using a Pulsed Plasma Discharge in Subsonic Flow

Stable combustion in a harsh environment, such as lean fuel concentration and/or low temperature conditions, is attractive because of its low emissions. However, such flames suffer from lack of stability. In our research, an AC plasma discharge is applied to a lifted jet flame to increase the stability of the flame. Two types of discharges are utilized for this experiment. First, a single elect...

Numerical Simulation of a Confined Swirling Flow in a Model Gas Turbine Combustor

Harmonically forced enclosed swirling flow

Y. D. Cui, J. M. Lopez, T. T. Lim, and F. Marques Temasek Laboratories, National University of Singapore, Singapore 119260, Singapore School of Mathematical and Statistical Sciences, Arizona State University, Tempe, Arizona 85287, USA Department of Mechanical Engineering, National University of Singapore, Singapore 119260, Singapore Departament de Física Aplicada, Universitat Politècnica de Cat...

Hierarchical Vortex Regions in Swirling Flow

We propose a new criterion to characterize hierarchical two-dimensional vortex regions induced by swirling motion. Central to the definition are closed loops that intersect the flow field at a constant angle. The union of loops belonging to the same area of swirling motion defines a vortex region. These regions are disjunct but may be nested, thus introducing a spatial hierarchy of vortex regio...