TY - JOUR

T1 - Discrete-vortex simulation of a turbulent separation bubble

AU - Kiya, Masaru

AU - Sasaki, Kyuro

AU - Arie, Mikio

PY - 1982

Y1 - 1982

N2 - The discrete-vortex model is applied to simulate the separation bubble over a two-dimensional blunt flat plate with finite thickness and right-angled corners, which is aligned parallel to a uniform approaching stream. This flow situation is chosen because, unlike most previous applications of the model, the separation bubble is supposed to be strongly affected by a nearby solid surface. The major objective of this paper is to examine to what extent the discrete-vortex model is effective for such a flow. A simple procedure is employed to represent the effect of viscosity near the solid surface; in particular, the no-slip condition on the solid surface. A reduction in the circulation of elemental vortices is introduced as a function of their ages in order to represent the three-dimensional deformation of vortex filaments. An experiment was also performed for comparison purposes. The calculation yielded reasonable predictions of the time-mean and r.m.s. values of the velocity and the surface-pressure fluctuations, together with correlations between their fluctuating components, over most of the separation bubble. The interrelation between instantaneous spatial variations of the surface-pressure and velocity fluctuations were also obtained. A comparison between the calculated and measured results suggests that, in the real flow, the three-dimensional deformation of vortex filaments will become more and more dominant as the reattachment point is approached.

AB - The discrete-vortex model is applied to simulate the separation bubble over a two-dimensional blunt flat plate with finite thickness and right-angled corners, which is aligned parallel to a uniform approaching stream. This flow situation is chosen because, unlike most previous applications of the model, the separation bubble is supposed to be strongly affected by a nearby solid surface. The major objective of this paper is to examine to what extent the discrete-vortex model is effective for such a flow. A simple procedure is employed to represent the effect of viscosity near the solid surface; in particular, the no-slip condition on the solid surface. A reduction in the circulation of elemental vortices is introduced as a function of their ages in order to represent the three-dimensional deformation of vortex filaments. An experiment was also performed for comparison purposes. The calculation yielded reasonable predictions of the time-mean and r.m.s. values of the velocity and the surface-pressure fluctuations, together with correlations between their fluctuating components, over most of the separation bubble. The interrelation between instantaneous spatial variations of the surface-pressure and velocity fluctuations were also obtained. A comparison between the calculated and measured results suggests that, in the real flow, the three-dimensional deformation of vortex filaments will become more and more dominant as the reattachment point is approached.

UR - http://www.scopus.com/inward/record.url?scp=84971922717&partnerID=8YFLogxK

UR - https://www.cambridge.org/core/journals/journal-of-fluid-mechanics/article/discretevortex-simulation-of-a-turbulent-separation-bubble/85885DDD848310AF0EF69AB8105D0004

U2 - 10.1017/S0022112082002742

DO - 10.1017/S0022112082002742

M3 - Article

AN - SCOPUS:84971922717

SN - 0022-1120

VL - 120

SP - 219

EP - 244

JO - Journal of Fluid Mechanics

JF - Journal of Fluid Mechanics

ER -