The thermal behavior of air by natural convection in a confined trapezoidal cavity, one of the walls of which is subjected to a constant heat flow in hot climates, has been analyzed numerically. The heat and mass transfers are carried out by the classical equations of natural convection. These equations are discretized using the Finite Difference Method and the algebraic systems of equations thus obtained are solved with the Thomas and Gauss algorithms. We analyze the influence of the number on the current and isothermal lines as well as the effects of the aspect ratio A = l / H and the angle of inclination φ. In particular, we have shown that convective exchanges in the cavity are preponderant for high Ra numbers. Also we have watches the increase in the values ​​of the isothermal lines and the decrease in the intensity of the streamlines for the low values ​​of A and of the angle φ.

The thermal performance of three roofing models: tile, corrugated and earth terrace is numerically analyzed. The mathematical equations which govern the three roofing models are established by the electrical method of analogies. These equations are discretized by an implicit finite difference method and solved by the Gauss-Seidel algorithm. We analyze the influences of geometric parameters (Xlo, Xlarg, α and Ep) on the evolution of the temperatures of the different environments of our three roof models. In particular, we have shown that the effectiveness of a roof in reducing the temperature inside a room is linked to its physical properties. The results obtained that for the same geometric parameters, the earth roof terrace and the earth tile roof compared to the corrugated metal roof improve thermal comfort by lowering the interior temperature of 5˚C and 4.6˚C.

This work focuses on modeling the impact of desert aerosols on a mini central solar photovoltaic (PV). Our studied physical model is comparable to a multilayer. We have described and discretized the mathematical equations which govern the physical model. Also, we analyzed the influence of the pa-I = . These results show that desert aerosols significantly influence the global solar radiation received. Unfortunately, this influence lowers the productivity of the central solar PV in general.

<p>The cook stove is usually constructed from black-painted sheet metal, to better absorb energy. To enhance thermal performance, a theoretical cylindrical design is proposed in this article. This article aims to study this design and compare its performance with the conical design. Theoretical modeling of the cook stove was carried out considering heat transfer by radiation, convection, and conduction based on a steady-state thermal network, and solved using the Matlab R2021b^® platform under license (License No. 595687). The result of the theoretical analysis predicts a theoretical efficiency of 65%, a pot air temperature <em>T_f</em>=220^oC and a flame temperature <em>Ta</em>=900^oC. Similarly, a validation with Sagouong's model on combustion chamber temperature and Kaushik's model on thermal efficiency. A maximum threshold (RMSE)  of 4% is observed between the two studies. The <em>T<span style="font-size: 8.33333px;">c</span></em> temperature stagnates rapidly within 5 minutes at 600^oC and the comparison showed that the firing temperatures of the cylindrical shape are higher than those of the conical-shaped cook stove. Consequently, the performance of the cylindrical-shaped cooking stove can be improved by further experimentation and flue gas analysis.</p>