A two-phase boundary-layer model for laminar mixed-convection condensation with a noncondensable gas on inclined plates

1998 ◽  
Vol 34 (4) ◽  
pp. 271-277 ◽  
Author(s):  
Y. S. Chin ◽  
S. J. Ormiston ◽  
H. M. Soliman
Keyword(s):  
Boundary Layer ◽  
Mixed Convection ◽  
Phase Boundary ◽  
Layer Model ◽  
Two Phase ◽  
Noncondensable Gas ◽  
Boundary Layer Model ◽  
Laminar Mixed Convection ◽  
Inclined Plates

Using an improved 1D boundary layer model with CFD for flux prediction in gas-sparged tubular membrane ultrafiltration

2005 ◽  
Vol 51 (6-7) ◽  
pp. 69-76 ◽  
Author(s):  
S.R. Smith ◽  
T. Taha ◽  
Z.F. Cui
Keyword(s):  
Boundary Layer ◽  
Mass Transfer ◽  
Shear Stress ◽  
Porous Wall ◽  
Transfer Model ◽  
Layer Model ◽  
Two Phase ◽  
Flow Process ◽  
Tubular Membrane ◽  
Boundary Layer Model

Tubular membrane ultrafiltration and microfiltration are important industrial separation and concentration processes. Process optimisation requires reduction of membrane build-up. Gas slug introduction has been shown to be a useful approach for flux enhancement. However, process quantification is required for design and optimisation. In this work we employ a non-porous wall CFD model to quantify hydrodynamics in the two-phase slug flow process. Mass transfer is subsequently quantified from wall shear stress, which was determined from the CFD. The mass transfer model is an improved one-dimensional boundary layer model, which empirically incorporates effects of wall suction and analytically includes edge effects for circular conduits. Predicted shear stress profiles are in agreement with experimental results and flux estimates prove more reliable than that from previous models. Previous models ignored suction effects and employed less rigorous fluid property inclusion, which ultimately led to under-predictive flux estimates. The presented model offers reliable process design and optimisation criteria for gas-sparged tubular membrane ultrafiltration.

Application of a boundary-layer model to flow over an eolian dune

1985 ◽  
Vol 90 (D6) ◽  
pp. 10631-10640 ◽  
Author(s):  
John L. Walmsley ◽  
Alan D. Howard
Keyword(s):  
Boundary Layer ◽  
Layer Model ◽  
Boundary Layer Model

A logarithmic bottom boundary layer model for the unsteady and non-uniform swash flow

2021 ◽  
pp. 104048
Author(s):  
Fangfang Zhu ◽  
Nicholas Dodd ◽  
Riccardo Briganti ◽  
Magnus Larson ◽  
Jie Zhang
Keyword(s):  
Boundary Layer ◽  
Bottom Boundary Layer ◽  
Layer Model ◽  
Bottom Boundary ◽  
Boundary Layer Model

Two-Phase Boundary Layer Treatment for Subcooled Free-Convection Film Boiling Around a Body of Arbitrary Shape in a Porous Medium

1987 ◽  
Vol 109 (4) ◽  
pp. 997-1002 ◽  
Author(s):  
A. Nakayama ◽  
H. Koyama ◽  
F. Kuwahara
Keyword(s):  
Boundary Layer ◽  
Porous Medium ◽  
Free Convection ◽  
Phase Boundary ◽  
Flat Plate ◽  
Arbitrary Shape ◽  
Film Boiling ◽  
Two Phase ◽  
The One ◽  
Axisymmetric Bodies

The two-phase boundary layer theory was adopted to investigate subcooled free-convection film boiling over a body of arbitrary shape embedded in a porous medium. A general similarity variable which accounts for the geometric effect on the boundary layer length scale was introduced to treat the problem once for all possible two-dimensional and axisymmetric bodies. By virtue of this generalized transformation, the set of governing equations and boundary conditions for an arbitrary shape reduces into the one for a vertical flat plate already solved by Cheng and Verma. Thus, the numerical values furnished for a flat plate may readily be tranlsated for any particular body configuration of concern. Furthermore, an explicit Nusselt number expression in terms of the parameters associated with the degrees of subcooling and superheating has been established upon considering physical limiting conditions.

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