Modeling the Unsteady Flow in a Turbine Rotor Passage

1988 ◽  
Vol 110 (1) ◽  
pp. 27-37 ◽  
Author(s):  
D. J. Doorly
Keyword(s):  
Boundary Layer ◽  
Heat Flux ◽  
Reynolds Number ◽  
Surface Heat Flux ◽  
Rotor Blade ◽  
Turbine Rotor ◽  
Surface Heat ◽  
Experimental Simulation ◽  
Blade Row ◽  
Wake Passing

The effects of the wakes shed by an upstream blade row in forcing the transition of an otherwise laminar rotor blade boundary layer are well recognized. Previous experiments have demonstrated that the forced transition of the laminar boundary layer may greatly influence the surface heat flux. The effect of the wakes on the surface heat flux when the undisturbed boundary layer is already turbulent have been studied using an experimental simulation technique. The results have been analyzed with a view to establishing how well the effects of the wakes can be described by a model which treats only their turbulence content. The effects of wake passing at a reduced Reynolds number are also reported.

Boundary-Layer Disturbances and Surface Heat-Flux Profiles on a Cooled Slender Cone

2022 ◽  
Author(s):  
Laura A. Paquin ◽  
Shaun Skinner ◽  
Stuart J. Laurence
Keyword(s):  
Boundary Layer ◽  
Heat Flux ◽  
Surface Heat Flux ◽  
Surface Heat

Boundary-layer flow of a micropolar fluid on a continuous flatplate moving in a parallel stream with uniform surface heat flux

2007 ◽  
Vol 85 (8) ◽  
pp. 869-878 ◽  
Author(s):  
A Ishak ◽  
R Nazar ◽  
I Pop
Keyword(s):  
Boundary Layer ◽  
Heat Flux ◽  
Boundary Layer Flow ◽  
Surface Heat Flux ◽  
Micropolar Fluid ◽  
Free Stream ◽  
Velocity Ratio ◽  
Skin Friction Coefficient ◽  
Surface Heat ◽  
Layer Flow

The laminar boundary-layer flow of a micropolar fluid on a fixed or continuously moving flat plate with uniform surface heat flux is investigated. The plate is assumed to move in the same oropposite direction to the free stream. The resulting system of nonlinear ordinary differential equations is solved numerically using the Keller-box method. Numerical results are obtained for the skin-friction coefficient and the local Nusselt number as well as the velocity, microrotation, and temperature profiles for some values of the governing parameters, namely, the velocity ratio parameter, material parameter, and Prandtl number. The results indicate that dual solutions exist when the plate and the free stream move in the opposite directions.PACS No.: 47.15.Cb

Continents as a chemical boundary layer

1981 ◽  
Vol 301 (1461) ◽  
pp. 359-373 ◽  
Keyword(s):  
Boundary Layer ◽  
Heat Flux ◽  
Surface Heat Flux ◽  
Evolutionary History ◽  
Surface Heat ◽  
Low Density ◽  
Alternate Model ◽  
Mantle Component ◽  
Double Diffusive

Tectospheric structure can be described in terms of three basic types of surficial boundary layers: chemical (c.b.l.), mechanical (m.b.l.) and thermal (t.b.l.). Beneath old ocean basins the thickness of the c.b.l. ( ca . 40 km) is less than that of either the m.b.l. ( ca . 100 km) or the t.b.l. ( ca . 150 km), but the hypothesis that a similar structure underlies the old continental cratons is difficult to reconcile with seismic observations. We therefore examine an alternate model which postulates a much thicker c.b.l. beneath the cratons whose mantle component consists of a low-density peridotite depleted in its basaltic constituents. On the basis of seismological and petrological data it is inferred that this augmented c.b.l. extends below the m.b.l. to depths exceeding 150 km and acts to stabilize a thick ( > 200 km) t.b.l. against convective disruption. Because of its refractory nature the sub-m.b.l. portion of the c.b.l. constitutes a stable geochemical reservoir which has evidently been impregnated by large-ion lithophile elements fluxing from the deep mantle or from descending slabs. Consequently, its heat production is high ( ca . 0.1 μW/m 3 ) and it contributes significantly to the surface heat flux. The evolutionary history and dynamics of the continental c.b.l. are not well understood, especially the role of double-diffusive instabilities, but the fusion of the continental masses into ‘supercontinents’ and the orogenic compression that this entails are thought to be important processes in c.b.l. formation.

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