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Anthony G. Straatman

Other affiliations: University of Waterloo
Bio: Anthony G. Straatman is an academic researcher from University of Western Ontario. The author has contributed to research in topics: Heat transfer & Porous medium. The author has an hindex of 19, co-authored 89 publications receiving 1305 citations. Previous affiliations of Anthony G. Straatman include University of Waterloo.


Papers
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Journal ArticleDOI
TL;DR: In this paper, a mathematical and numerical model for the treatment of conjugate fluid flow and heat transfer problems in domains containing pure fluid, porous, and pure solid regions is presented.
Abstract: A mathematical and numerical model for the treatment of conjugate fluid flow and heat transfer problems in domains containing pure fluid, porous, and pure solid regions is presented. The model is general and physically reasoned, and allows for local thermal nonequilibrium in the porous region. The model is developed for implementation on a simple collocated finite-volume grid. Special attention is given to the matching of the interfacial heat flux, the approximation of advected variables at the interface between pure fluid and porous regions, the pressure–velocity coupling at such an interface, and the estimation of pressure values at the interface.

113 citations

Journal ArticleDOI
TL;DR: In this article, a unit-cube geometry model is proposed to characterize the internal structure of porous carbon foam, where the interconnected sphere-centered cubes represent the fluid or void phase, and the model is used to derive all of the geometric parameters required to calculate the heat transfer and flow through the porous foam.
Abstract: A unit-cube geometry model is proposed to characterize the internal structure of porous carbon foam. The unit-cube model is based on interconnected sphere-centered cubes, where the interconnected spheres represent the fluid or void phase. The unit-cube model is used to derive all of the geometric parameters required to calculate the heat transfer and flow through the porous foam. An expression for the effective thermal conductivity is derived based on the unit-cube geometry. Validations show that the conductivity model gives excellent predictions of the effective conductivity as a function of porosity. When combined with existing expressions for the pore-level Nusselt number, the proposed model also yields reasonable predictions of the internal convective heat transfer, but estimates could be improved if a Nusselt number expression for a spherical void phase material were available. Estimates of the fluid pressure drop are shown to be well-described using the Darcy-Forchhiemer law, however, further exploration is required to understand how the permeability and Forchhiemer coefficients vary as a function of porosity and pore diameter.

97 citations

Journal ArticleDOI
TL;DR: There appears to be some promise for simulating physiological pulsatile flows using a relatively simple two-equation turbulence model for sinusoidally pulsatile flow in 75% and 90% area reduction stenosed vessels.
Abstract: The study of pulsatile flow in stenosed vessels is of particular importance because of its significance in relation to blood flow in human pathophysiology. To date, however, there have been few comprehensive publications detailing systematic numerical simulations of turbulent pulsatile flow through stenotic tubes evaluated against comparable experiments. In this paper, two-equation turbulence modeling has been explored for sinusoidally pulsatile flow in 75% and 90% area reduction stenosed vessels, which undergoes a transition from laminar to turbulent flow as well as relaminarization. Wilcox's standard k-omega model and a transitional variant of the same model are employed for the numerical simulations. Steady flow through the stenosed tubes was considered first to establish the grid resolution and the correct inlet conditions on the basis of comprehensive comparisons of the detailed velocity and turbulence fields to experimental data. Inlet conditions based on Womersley flow were imposed at the inlet for all pulsatile cases and the results were compared to experimental data from the literature. In general, the transitional version of the k-omega model is shown to give a better overall representation of both steady and pulsatile flow. The standard model consistently over predicts turbulence at and downstream of the stenosis, which leads to premature recovery of the flow. While the transitional model often under-predicts the magnitude of the turbulence, the trends are well-described and the velocity field is superior to that predicted using the standard model. On the basis of this study, there appears to be some promise for simulating physiological pulsatile flows using a relatively simple two-equation turbulence model.

97 citations

Journal ArticleDOI
TL;DR: In this paper, an engineering model is formulated to account for the effects of porosity and pore diameter on the hydrodynamic and thermal performance of a carbon-foam finned tube heat exchanger.

79 citations

Journal ArticleDOI
TL;DR: In this paper, the authors quantify the convective heat transfer that is obtained by passing parallel airflow over a layer of porous carbon foam bonded onto a solid substrate, and show that the increase in heat transfer is inversely proportional to Reynolds number and decreased from about 28-10% over the Reynolds number range 150,000-500,000.

71 citations


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Book ChapterDOI
01 Jan 1997
TL;DR: The boundary layer equations for plane, incompressible, and steady flow are described in this paper, where the boundary layer equation for plane incompressibility is defined in terms of boundary layers.
Abstract: The boundary layer equations for plane, incompressible, and steady flow are $$\matrix{ {u{{\partial u} \over {\partial x}} + v{{\partial u} \over {\partial y}} = - {1 \over \varrho }{{\partial p} \over {\partial x}} + v{{{\partial ^2}u} \over {\partial {y^2}}},} \cr {0 = {{\partial p} \over {\partial y}},} \cr {{{\partial u} \over {\partial x}} + {{\partial v} \over {\partial y}} = 0.} \cr }$$

2,598 citations

Journal ArticleDOI
TL;DR: In this paper, a review of the recent progress of the investigations and applications of composite phase change materials with the enhanced performance is presented, where the focus is placed on the composite PCMs fabricated by using the metal foams and carbon materials, which have proved to be the most promising approaches for thermal conductivity and heat transfer promotion on PCMs.

401 citations

Journal ArticleDOI

350 citations