The solar photovoltaic-thermal energy, it is a combination of Photovoltaic (PV) and solar thermal components integrated into one system and enables to generate electricity and heat simultaneously. The solar chimney can generate air flow through the living space of the building to provide cooling. Hence, there is a greater interest to study the mixed convection in the hybrid Photovoltaic-Thermal chimney integrated into buildings for natural room ventilation for thermal comfort. The thermal efficiency has been studied by analysing numerically the mixed convection in the hybrid photovoltaic-thermal chimney integrated into the building in the present paper. The stream fucntion-vorticity formulation with a finite difference numerical discretization solution scheme have been adopted. The system of algebraic governing equations is solved by Thomas algorithm method. The aim of the present paper is to study and to predict the dynamic fields and particularly of the mass flow rate of the air thermosiphon drawing in the hybrid Photovoltaic-Thermal chimney integrated into a building for passive cooling in the room. The effects of the governing parameters, particularly Grashof number (10 3 ≤ Gr ≤ 10 6), that depends of the solar radiation intensity in the region, the mass flow rate of the inlet fresh air (0.001 Kg.s-1 ≤ D m ≤ 0.3Kg.s-1), the integrated chimney width on fluid flow and the heat transfer characteristics are studied in detail. Passive cooling and the electrical efficiency of the PV solar cells are increasing function of the intensity of the inlet air flow. Due to the possible reduction of cooling loads with the insertion of the photovoltaic cells plate into the chimney integrated into the building. The numerical simulation has been conducted to determine heat transfer, mass flow rate trough the chimney exit, solar cells PV efficiency and the effect of design parameters of the room and the integrated hybrid Photovoltaic-Thermal chimney to make the bioclimatic building energy autonomy. The outlet velocity, streamlines, isotherms, Nusselt number along the active walls, and the mass flow rate are plotted versus the above controlling parameters.

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We investigate heat and mass transfer in an isosceles trapezoidal cavity, filled with charcoal considered as a granular porous medium. The Darcy-Brinkman-Forchheimer flow model is coupled to the energy and mass equations with the assumption of non-thermal equilibrium. These equations are discretized by the finite volume method with an offset mesh and then solved by the line-by-line method of Thomas. The coupling between pressure and velocity is obtained by Semi-Implicit Method for Pressure Linked Equations. (SIMPLE) algorithm. The results show that the temperature in the cavity increases when the inclination angle of the sides walls decreases. The 15˚ inclination is selected as being able to offer better thermal performance in the cookstove combustion chamber.

This study reports the results on a numerical investigation of the depollution of smokes produced by the incineration of household wastes in a cylindrical furnace. Transfers are described by double-diffusive mixed convection equations, associated to radiative transfer equation, and a global kinetics model. The governing equations are discretized using finite volume method and the resulting algebraic equations are solved by THOMAS algorithm. The linkage between the pressure and velocity fields is assumed by SIMPLE algorithm. Results are presented as streamlines, isotherms, isoconcentrations for different Reynolds number (300 ≤ Re ≤ 1800). Effects of Reynolds number, relative height opening, aspect ratio, excess air ratio, and radiative transfers on gas pollutants (CO, CH4, C2H4…) destruction are investigated in detail.

In this work, a laminar forced convection air flow in a rectangular vertical venturi has been numerically simulated. Mathematical transformation has been used to transform the irregular profile of the venturi wall into straight line. Transfers equations are solved using finite volume method, Gauss and Thomas algorithms. A computing algorithm has been generated for the problem simulation. Hydrodynamics and thermals effects are investigated in detail. Results are presented as velocity and streamlines patterns, and temperature profiles.