On the fluidic behavior of an over-expanded planar plug nozzle under lateral confinement
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.
Keywords
Cite
@article{arxiv.2006.00454,
title = {On the fluidic behavior of an over-expanded planar plug nozzle under lateral confinement},
author = {M. Chaudhary and T. V. Krishna and Sowmya R. Nanda and S. K. Karthick and A. Khan and A. De and S. Mohammed Ibrahim},
journal= {arXiv preprint arXiv:2006.00454},
year = {2020}
}
Comments
14 pages, 12 figures, Revision submitted to Phys. Fluids