Aircraft on approach in high-drag and high-lift configuration create unsteady flow structures which inherently generate noise. For devices such as flaps, spoilers and the undercarriage there is a strong correlation between overall noise and drag such that, in the quest for quieter aircraft, one challenge is to generate drag at low noise levels. This paper presents a rigorous aero-acoustic asses...

In general, a feature can be defined as a pattern occurring in a dataset that is the manifestation of correlations among various components of the data. For many features that occur in scientific data, these correlations can be defined precisely. For other features, they are not well understood or do not lend themselves to precise definitions. Surprisingly, the swirling feature in flow fields, ...

In this study, mechanisms that cause the occurrence of a swirling vortex without an intake are explained. There more than one different reasons which may air-core or swirling-vortex flow filament within ambient fluid. An can also occur in fluid media provided coaxial subsurface depressions and thereby imaginary spherical sink surface sectors hydraulically developed by any means (such as rotatio...

Impinging jets are used in a wide number of industrial cooling applications due to their high heat and mass transfer abilities. The current research is concerned with the effect of swirl on the heat transfer characteristics of jet impingement cooling. Two inserts were designed order to generate swirling flow. These two designs, “Swirl Insert A” and “Swirl Insert B”, were tested at various Reyno...

Submitted for the DFD13 Meeting of The American Physical Society Axial Evolution of Helical Modes in Reacting Swirl Flow MIKE AGUILAR, BENJAMIN EMERSON, DAVID NOBLE, TIM LIEUWEN, Georgia Institute of Technology — The swirling jet is a common method of flame stabilization for ground power and aviation combustors. The hydrodynamic stability characteristics of high Reynolds number, reacting, swirl...

Rayleigh scattering temperature measurements were obtained in a turbulent reactive swirling coaxial jet discharged from a swirl-stabilized burner along the jet-flame centerline. They are reported up to 10 fuel nozzle diameters downstream of the burner exit at a Reynolds number of 29000. The effect of swirl numbers (S=0.3, 0.58, 1.07) on the temperature fields, the power spectral density of temp...

In a recent paper [Phys. Rev. E 85, 016308 (2012)], we reported on numerical simulations of swirling two-phase flows in which for cases where the viscosity of the upper fluid is sufficiently smaller than that of the lower fluid, a small region of reversed flow is present on the interface. In this Brief Report, we show that the reported reversed flow is grid converged and comment further on its ...

We experimentally study the susceptibility to symmetry breaking of a closed turbulent von Kármán swirling flow from Re=150 to Re≃10⁶. We report a divergence of this susceptibility at an intermediate Reynolds number Re=Re(χ)≃90,000 which gives experimental evidence that such a highly space and time fluctuating system can undergo a "phase transition." This transition is furthermore associated wit...