This work presents a similarity solution for boundary layer flow through a porous medium over a stretching porous wall. Two considered wall boundary conditions are powerlaw distribution of either wall temperature or heat flux which are general enough to cover the isothermal and isoflux cases. In addition to momentum, both first and second laws of thermodynamics analyses of the problem are inves...

The design of concentric ring arrays for isoflux radiation is reported in this paper. This design considers the reduction of the side lobe level and the isoflux radiation requirements for Geostationary Earth Orbit (GEO) satellites. The optimization problem considers the spacing between rings and the levels of amplitude excitations. The wellknown method of Particle Swarm Optimization (PSO) is ut...

Abstract—This paper presents a study on the effect of second-order slip on forced convection through a long isoflux heated or cooled planar microchannel. The fully developed solutions of flow and thermal fields are analytically obtained on the basis of the second-order Maxwell-Burnett slip and local heat flux boundary conditions. Results reveal that when the average flow velocity increases or t...

The design of concentric ring arrays for isoflux radiation is presented in this paper. This design considers the reduction of the side lobe level and isoflux radiation requirements for Medium Earth Orbit (MEO) satellites. The optimization problem considers the spacing among rings and levels of amplitude excitations. The well-known method of Particle Swarm Optimization (PSO) is utilized for this...

A new compact analytical model is developed to predict transient heat convection from isoflux vertical plates into a constant property surrounding region. The proposed model is based on a blending of the two asymptotes corresponding to transient diffusion into a half-space and the steady-state convection heat transfer from an isoflux vertical plate. A compact relation for transient and steady-s...

An integral approach is employed to investigate the effects of blockage on fluid flow and heat transfer from a circular cylinder confined between parallel planes. The integral form of the boundary-layer momentum equation is solved using the modified von Kármán–Pohlhausen method, which uses a fourth-order velocity profile inside the hydrodynamic boundary layer. The potential flow velocity, outsi...

The scope of this study is to determine the conditions for onset instability in a horizontal porous layer subject isoflux boundary and with an infinitely wide single–cell basic flow. When circulation cellular flow absent, one recovers usual Darcy–Bénard conduction state. governing parameters are Rayleigh number associated uniform wall heat flux, dimensionless temperature gradient. latter parame...

Triangular enclosures are typical configurations found in attic spaces of residential as well as industrial pitched-roof buildings. Previous studies on airflow within such spaces have focused on the laminar range. A numerical study has been carried out for time-dependent, two-dimensional low turbulence natural convection of air contained in the attic of a pitched roof of triangular crosssection...

The onset of the thermal instability is investigated in a porous channel with plane parallel boundaries saturated by non–Newtonian shear–thinning fluid and subject to horizontal throughflow. Ellis model adopted describe rheology. Both are assumed be impermeable. A uniform heat flux supplied through lower boundary, while upper boundary kept at temperature. Such an asymmetric setup conditions ana...