Direct numerical simulation of two opposing wall jets

Johansson, Peter S.; Andersson, Helge I.

doi:10.1063/1.1920627

Cited by 20 publications

(13 citation statements)

References 37 publications

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“…It should be pointed out that none of these numerical simulations about the planar opposed jets has predicted the deflecting oscillation. The experimental and numerical studies of the planar wall opposed jets have not reported such kind of deflecting oscillation either, 25,26 a) Author to whom correspondence should be addressed. Electronic mail: liweif@ecust.edu.cn.…”

Section: Introductionmentioning

confidence: 99%

Experimental study of planar opposed jets with acoustic excitation

Guo-Feng

et al. 2013

Physics of Fluids

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Oscillation behaviors of planar opposed jets with acoustic excitation were experimentally investigated. The flow regimes of planar opposed jets at various exit air velocities, nozzle separations, excitation frequencies, and excitation amplitudes have been identified by a flow visualization technique combining with a high-speed camera. Results show that planar opposed jets exhibit horizontal instability at L/H ≤ 4 (where L is the nozzle separation and H is the slit height of the planar nozzle) and deflecting oscillation at L/H ≥ 6. The deflecting oscillation is originally started by the antisymmetric structures in the planar jets and is self-sustained by the periodic changes of the velocity field and the pressure field. At L/H ≤ 4, the acoustic excitation results in the horizontal periodic oscillation, whose frequency is equal to the excitation frequency. The acoustic excitation of oscillation amplitude less than 10% has negligible influence on the deflecting oscillation; for synchronous or asynchronous excitation with higher amplitude, the transition from the deflecting oscillation to a steady state or horizontal oscillation occurs.

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Section: Introductionmentioning

confidence: 99%

Experimental study of planar opposed jets with acoustic excitation

Guo-Feng

et al. 2013

Physics of Fluids

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“…However, the contribution of the velocity-pressure correlation in the transport equation of turbulence has not been well investigated. In particular, pressure-diffusion transport is expected to become significant for this flow as is suggested by previous studies of the near-wake [11] and the impinging wall-jet [12] which show the remarkable contribution of the pressure-diffusion term in the budget of the turbulent kinetic energy equation.…”

Section: Introductionmentioning

confidence: 56%

Simultaneous Measurement of Velocity and Fluctuating Pressure in a Turbulent Wing-tip Vortex Using Triple Hot-film Sensor and Miniature Total Pressure Probe

Kawata

Naka

Fukagata

et al. 2010

Flow Turbulence Combust

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We have developed a probe-system for simultaneous measurement of three velocity components and pressure in turbulent flows. A miniature total pressure probe is placed adjacent to the sensors of a triple hot-film probe in order to achieve the spatial resolution which is equivalent to that of the triple hot-film probe itself. The instantaneous static pressure is calculated from measured velocity and total pressure by means of a newly developed processing method based on the Bernoulli equation for unsteady flows. The measurements were undertaken in a turbulent wing-tip vortex flow. The look-up table method is employed for the calibration of the hot-film probe so accurate velocity data could be obtained over a wide range of the flow-attack angles. It is also demonstrated that the present probesystem is capable of measuring fluctuations in both velocity and pressure in the 20-650 Hz frequency range. The distribution of the fluctuating pressure obtained by this indirect method is in good agreement with the results from direct measurements of static pressure, demonstrating the promising performance of the present method. Furthermore, an improvement in the ability to make measurements of the velocitypressure correlation across the wing-tip vortex is achieved. This improvement is possible because the effects of lateral velocity components are properly taken into account in the present formulation. The investigation regarding the transport equation budget for turbulent kinetic energy shows an anomalous structure of turbulence in this flow, mainly due to the meandering of the vortex, and the measurement of pressure diffusion is found to play an important role in the characterization of this kind of flow.

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“…The flow direction of this jet depends with extreme sensitivity on an even very small dissimilarity in momentum flow rates of the colliding flows. A particularly suitable case was found in colliding wall jets [17][18][19], formed on a common solid surface.…”

Section: Introductionmentioning

confidence: 99%