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Hydrodynamic and thermal measurements in a turbulent boundary layer recovering from concave curvature
Michael D. Kestoras,Terrence W. Simon +1 more
- pp 29-35
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The behavior of a boundary layer on a flat wall downstream of sustained concave curvature is documented in this paper, with negligible streamwise pressure gradient and a low free-stream turbulence intensity (0.6 percent).Abstract:
The behavior of a boundary layer on a flat wall downstream of sustained concave curvature is documented. Experiments are conducted with negligible streamwise pressure gradient and a low free-stream turbulence intensity (0.6 percent). The turbulent boundary layer has a moderate strength of curvature (δ/R = 0.024) at the entry to the recovery section. Results show that the skin friction coefficient, which increases over the concave wall, decreases rapidly at first over the recovery wall, then slowly approaches flat-wall values. Stanton number values decrease rapidly, undershooting expected flat-wall values. A discussion of this behavior, supported by profile measurements, is given. Effects include destabilization in the concave-curved flow and rapid streamline readjustment (acceleration) at the end of the curved section. Goertler vortices established on the curved wall persist onto the recovery wall; however, their effects weaken.read more
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Turbulent transport measurements in a heated boundary layer: Combined effects of free-stream
M. D. Kestoras,Terrence W. Simon +1 more
TL;DR: In this article, the boundary layer appears turbulent from the beginning of the upstream, concave wall and grows over the flat test wall downstream of the curved wall with negligible streamwise acceleration.
References
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Journal ArticleDOI
Effects of curvature variations on the nonlinear evolution of Goertler vortices
Ali Benmalek,William S. Saric +1 more
TL;DR: In this paper, the nonlinear development of Goertler vortices over walls of variable curvature is studied, and the parabolized disturbance equations governing the problem for small curvature, high Reynolds number, and order unity goertler number are integrated numerically.
Journal ArticleDOI
Measurements of turbulence quantities and bursting period in developing turbulent boundary layers on the concave and convex walls of a 90° square bend
TL;DR: The results of an experimental study of developing turbulent boundary layers on the concave and convex walls of a 90° bend of square cross-section using hot-wire anemometry are presented in this paper.
Journal ArticleDOI
Effects of Free-Stream Turbulence Intensity on a Boundary Layer Recovering From Concave Curvature Effects
TL;DR: In this article, a turbulent boundary layer grows from the leading edge of a concave wall, then passes onto a downstream flat wall, and turbulence intensities increase profoundly in the outer region of the boundary layer over the recovery wall.
Journal ArticleDOI
Heat-transfer analysis of a transitional boundary layer over a concave surface with Görtler vortices by means of direct numerical simulations
TL;DR: In this paper, the development of a thermal boundary layer during the laminar-to-turbulent transition process over a concave surface is studied, where the temperature variable is treated as a passive scalar.
Journal ArticleDOI
Parametric study of mixed convection in channels with concave and convex surfaces
TL;DR: In this article, mixed convection heat transfer in channels with a heated curved surface bounded by a vertical adiabatic wall has been studied numerically, and the results were obtained for various curvature ratios (R / L ) of the concave/convex wall and compared with straight channels of equal heated lengths and equal heights.