On the fluidic behavior of an over-expanded planar plug nozzle under lateral confinement
| Autor: | S. K. Karthick, Ashoke De, Aqib Khan, Soumya Ranjan Nanda, T. V. Krishna, M. Chaudhary, Ibrahim M. Sugarno |
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| Rok vydání: | 2020 |
| Předmět: |
Fluid Flow and Transfer Processes
Flow visualization Physics Shock (fluid dynamics) Mechanical Engineering Nozzle Flow (psychology) Computational Mechanics Fluid Dynamics (physics.flu-dyn) FOS: Physical sciences Physics - Fluid Dynamics Mechanics Condensed Matter Physics law.invention Pressure measurement Mechanics of Materials law Schlieren Spark plug Plug nozzle |
| DOI: | 10.48550/arxiv.2006.00454 |
| Popis: | 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. Comment: 14 pages, 12 figures, Revision submitted to Phys. Fluids |
| Databáze: | OpenAIRE |
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