TY - JOUR
T1 - Experimental characterization of smooth body flow separation topography and topology on a two-dimensional geometry of finite span
AU - Simmons, D. J.
AU - Thomas, F. O.
AU - Corke, T. C.
AU - Hussain, F.
N1 - Publisher Copyright:
© The Author(s), 2022. Published by Cambridge University Press.
PY - 2022/8/10
Y1 - 2022/8/10
N2 - A smooth body, adverse pressure gradient (APG), turbulent boundary layer (TBL) separation is experimentally studied. The geometry features canonical TBL development prior to encountering a smooth, two-dimensional convex ramp geometry of finite span onto which a streamwise APG that is fully adjustable is imposed. Both large-and small-scale separations are studied, and all data are archived on the NASA Turbulence Modeling Resource website. This paper describes the large-scale separation case with focus on the surface topography and topology of both separation and reattachment. Despite the spanwise uniform approach TBL and ramp geometry, the separation is highly three-dimensional but the reattachment is spanwise uniform. The surface flow topology is characterized by the 'owl-face pattern of the fourth kind'-found to be highly repeatable over multiple experiments. This ubiquitous topology has been reported for a variety of flows including inclined bodies of revolution. It is demonstrated that the APG and the secondary flow associated with the sidewall-ramp juncture is responsible for the formation of the surface separation patterns.
AB - A smooth body, adverse pressure gradient (APG), turbulent boundary layer (TBL) separation is experimentally studied. The geometry features canonical TBL development prior to encountering a smooth, two-dimensional convex ramp geometry of finite span onto which a streamwise APG that is fully adjustable is imposed. Both large-and small-scale separations are studied, and all data are archived on the NASA Turbulence Modeling Resource website. This paper describes the large-scale separation case with focus on the surface topography and topology of both separation and reattachment. Despite the spanwise uniform approach TBL and ramp geometry, the separation is highly three-dimensional but the reattachment is spanwise uniform. The surface flow topology is characterized by the 'owl-face pattern of the fourth kind'-found to be highly repeatable over multiple experiments. This ubiquitous topology has been reported for a variety of flows including inclined bodies of revolution. It is demonstrated that the APG and the secondary flow associated with the sidewall-ramp juncture is responsible for the formation of the surface separation patterns.
KW - boundary layer separation
KW - turbulent boundary layers
UR - http://www.scopus.com/inward/record.url?scp=85133867852&partnerID=8YFLogxK
U2 - 10.1017/jfm.2022.465
DO - 10.1017/jfm.2022.465
M3 - Article
AN - SCOPUS:85133867852
SN - 0022-1120
VL - 944
JO - Journal of Fluid Mechanics
JF - Journal of Fluid Mechanics
M1 - A42
ER -