Title: Computational study of supersonic flow past non-stationary obstructions part-II - moving protrusion

Authors: Vikram Deshpande; Brijesh Eshpuniyani; Sanjeev Sanghi

Addresses: Department of Applied Mechanics, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, 110016, India ' Department of Mechanical Engineering, Indian Institute of Technology (BHU), Varanasi, Uttar Pradesh, 221005, India ' Department of Applied Mechanics, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, 110016, India

Abstract: For an upward moving protrusion, recirculation regions develop on both sides with separation/reattachment distances increasing with protrusion height while being smaller than the corresponding fixed protrusion values. Differences in upstream wall pressures between moving versus fixed protrusions are reasoned in terms of: 1) extent of coalescence of upstream travelling compression waves into a shock; 2) inclination of this shock wave with free stream; 3) a low velocity high pressure band of fluid formed adjacent to the protrusion fore surface. Downstream wall pressures are lower than the corresponding fixed protrusion values due to a higher expansion of the flow for the range of protrusion heights considered. For an oscillating protrusion, wall pressure response to varying protrusion heights displays a hysteretic behaviour. Compressive/expansive effects generated during the protrusion's upward/downward motions persist after the protrusion changes its direction. Higher upstream and lower downstream wall pressures are observed in general at higher protrusion velocities.

Keywords: supersonic flow; moving protrusion; shock wave boundary layer interaction; SWBLI; pressure hysteresis; particle velocity upwinding scheme; PVUS; non-stationary obstructions; oscillating protrusion; wall pressure response; protrusion heights.

DOI: 10.1504/PCFD.2015.069579

Progress in Computational Fluid Dynamics, An International Journal, 2015 Vol.15 No.3, pp.157 - 167

Received: 08 May 2021
Accepted: 12 May 2021

Published online: 26 May 2015 *

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