Görtler vortices in boundary layers with streamwise pressure gradient: Linear theory

1996 ◽  
Vol 8 (2) ◽  
pp. 451-459 ◽  
Author(s):  
Pascal Goulpié ◽  
Barbro G. B. Klingmann ◽  
Alessandro Bottaro
Keyword(s):  
Pressure Gradient ◽  
Boundary Layers ◽  
Linear Theory ◽  
Görtler Vortices ◽  
Streamwise Pressure Gradient ◽  
Gortler Vortices

Buoyant convection from horizontal surfaces at const ant pressure

1975 ◽  
Vol 68 (3) ◽  
pp. 609-624 ◽  
Author(s):  
S. C. Traugott
Keyword(s):  
Pressure Gradient ◽  
Boundary Layers ◽  
Line Source ◽  
Leading Edge ◽  
Wall Jet ◽  
Two Dimensional ◽  
Buoyant Plume ◽  
Grashof Number ◽  
Buoyancy Driven Flows ◽  
Streamwise Pressure Gradient

A two-dimensional horizontal flow is discussed, which is induced by other, buoyancy-driven flows elsewhere. It is an adaptation of the incompressible wall jet, which is driven by conditions a t the leading edge and has no streamwise pressure gradient. The relation of this flow to the classical buoyancy-driven boundary layers on inclined and horizontal surfaces is investigated, as well as its possible connexion with a two-dimensional buoyant plume driven by a line source of heat. Composite flows are constructed by patching various such solutions together. The composite flows exhibit$Gr^{\frac{1}{4}}$scaling (Grbeing the Grashof number).

scholarly journals Effects of Criterion Functions on Intermittency in Heated Transitional Boundary Layers With and Without Streamwise Acceleration

1993 ◽  
Author(s):  
F. Jeffrey Keller ◽  
Ting Wang
Keyword(s):  
Pressure Gradient ◽  
Boundary Layers ◽  
Reynolds Shear Stress ◽  
Transitional Region ◽  
Criterion Function ◽  
Transitional Boundary Layer ◽  
Criterion Functions ◽  
Baseline Case ◽  
Streamwise Pressure Gradient

Attempting to understand the mechanisms of momentum and thermal transports in transitional boundary layers, has resulted in the use of conditional sampling to separate the flow into turbulent and non-turbulent portions. The choice of a proper criterion function to discriminate between the two flow conditions is critical. A detailed experimental investigation was performed to determine the effects of different criterion functions on the determination of intermittency for application in heated transitional boundary layers with and without streamwise acceleration. Nine separate criterion functions were investigated for the baseline case without pressure gradient and three cases with streamwise pressure gradient. Inherent differences were found to exist between each criterion function’s turbulence recognition capabilities. The results indicate that using a criterion function based on Reynolds shear stress, (∂uv∂τ)2, for turbulent/non-turbulent discrimination in a heated transitional boundary layer is superior to a single velocity or temperature scheme. Peak values in intermittency for the early to mid-transitional region were found to occur away from the wall at approximately y/δ = 0.3 for all cases. To match the universal intermittency distribution of Dhawan and Narasimha (1958), the minimum values of intermittency at y/δ ≈ 0.1 should be used as the representative “near-wall” values.

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