Dynamics of a spherical body shedding from a hypersonic ramp. Part 1. Inviscid flow: Part I: inviscid flow
Dynamics of a spherical body shedding from a hypersonic ramp. Part 1. Inviscid flow: Part I: inviscid flow
Numerical simulations are employed to investigate the dynamical separation of an initially stationary sphere from the surface of a two-dimensional ramp in hypersonic flow. We consider the inviscid limit, which is equivalent to assuming the sphere radius to be much larger than the ramp boundary-layer thickness; this assumption allows a range of Mach numbers and ramp angles to be explored efficiently. Of particular interest is determining how the shock-surfing phenomenon discovered by Laurence & Deiterding (J. Fluid Mech., vol. 676, 2011, pp. 396-431), in which a spherical body can stably oscillate about an oblique shock as it moves downstream, manifests itself in such a situation. First, the isolated interactions between a sphere and an oblique shock, and then between a sphere and an inviscid wall, are examined independently to elucidate relevant trends. Full trajectory predictions are subsequently performed using a decoupled model in which the shock and wall interactions are assumed to contribute independently to the aerodynamic forces. Three types of trajectories are found to be possible: surfing of the spherical body; initial expulsion outside the shock layer followed by re-Entry and entrainment; or direct entrainment. At relatively low hypersonic Mach numbers, the latter two types of trajectories are predominant, but at higher Mach numbers , surfing becomes possible over an increasingly wide range of ramp angles and downstream release locations. By reparameterizing the release location as the initial lateral distance of the sphere from the shock, good collapse of the transition boundary delineating surfing from ejection/re-Entrainment over various Mach numbers and ramp angles is obtained.
Key words high-speed flow, flow-structure interactions
Sousa, Cole
4d27f68e-d9c6-44a3-b5ff-26ca2d905b29
Deiterding, Ralf
ce02244b-6651-47e3-8325-2c0a0c9c6314
Laurence, Stuart J.
c9870caa-b37e-4ee1-b4a4-3b348c2f9bc0
10 January 2021
Sousa, Cole
4d27f68e-d9c6-44a3-b5ff-26ca2d905b29
Deiterding, Ralf
ce02244b-6651-47e3-8325-2c0a0c9c6314
Laurence, Stuart J.
c9870caa-b37e-4ee1-b4a4-3b348c2f9bc0
Sousa, Cole, Deiterding, Ralf and Laurence, Stuart J.
(2021)
Dynamics of a spherical body shedding from a hypersonic ramp. Part 1. Inviscid flow: Part I: inviscid flow.
Journal of Fluid Mechanics, 906, [A28].
(doi:10.1017/jfm.2020.756).
Abstract
Numerical simulations are employed to investigate the dynamical separation of an initially stationary sphere from the surface of a two-dimensional ramp in hypersonic flow. We consider the inviscid limit, which is equivalent to assuming the sphere radius to be much larger than the ramp boundary-layer thickness; this assumption allows a range of Mach numbers and ramp angles to be explored efficiently. Of particular interest is determining how the shock-surfing phenomenon discovered by Laurence & Deiterding (J. Fluid Mech., vol. 676, 2011, pp. 396-431), in which a spherical body can stably oscillate about an oblique shock as it moves downstream, manifests itself in such a situation. First, the isolated interactions between a sphere and an oblique shock, and then between a sphere and an inviscid wall, are examined independently to elucidate relevant trends. Full trajectory predictions are subsequently performed using a decoupled model in which the shock and wall interactions are assumed to contribute independently to the aerodynamic forces. Three types of trajectories are found to be possible: surfing of the spherical body; initial expulsion outside the shock layer followed by re-Entry and entrainment; or direct entrainment. At relatively low hypersonic Mach numbers, the latter two types of trajectories are predominant, but at higher Mach numbers , surfing becomes possible over an increasingly wide range of ramp angles and downstream release locations. By reparameterizing the release location as the initial lateral distance of the sphere from the shock, good collapse of the transition boundary delineating surfing from ejection/re-Entrainment over various Mach numbers and ramp angles is obtained.
Text
ramp_sphere_inviscid
- Accepted Manuscript
More information
Accepted/In Press date: 10 August 2020
e-pub ahead of print date: 16 November 2020
Published date: 10 January 2021
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Publisher Copyright:
© The Author(s), 2020.
Keywords:
Key words high-speed flow, flow-structure interactions
Identifiers
Local EPrints ID: 443281
URI: http://eprints.soton.ac.uk/id/eprint/443281
ISSN: 0022-1120
PURE UUID: dd150d20-446f-48f1-9f89-6e78b0294585
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Date deposited: 20 Aug 2020 16:30
Last modified: 17 Mar 2024 05:49
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Author:
Cole Sousa
Author:
Stuart J. Laurence
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