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arXiv · 2006.00454

On the fluidic behavior of an over-expanded planar plug nozzle under lateral confinement

M. Chaudhary·T. V. Krishna·Sowmya R. Nanda·S. K. Karthick·A. Khan·A. De·S. Mohammed Ibrahim
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Abstract

The present work aims to study the fluidic behavior on lateral confinement by placing side-walls on the planar plug nozzle through experiments. The study involves two cases of nozzle pressure ratio (NPR=3, 6), which correspond to over-expanded nozzle operating conditions. Steady-state pressure measurements, together with schlieren and surface oil flow visualization, reveal the presence of over-expansion shock and subsequent interaction and modification of the flow field on the plug surface. The flow remains attached to the plug surface for NPR=3; whereas, for NPR=6, a separated flow field with a recirculation bubble is observed. Spectral analysis of the unsteady pressure signals illustrates a clear difference between the attached and the separated flow. Besides, other flow features with a distinct temporal mode associated with and without lateral confinement are observed. The absence of lateral confinement reduces the intensity of low-frequency unsteadiness; however, on the contrary, the interaction region is relatively reduced under lateral confinement.

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M. Chaudhary, T. V. Krishna, Sowmya R. Nanda, S. K. Karthick, A. Khan, A. De, S. Mohammed Ibrahim. 2020-05-31. On the fluidic behavior of an over-expanded planar plug nozzle under lateral confinement. https://arxiv.org/abs/2006.00454

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