The production of thermal energy from solar energy by flat collectors finds nowadays many applications due to their innumerable economic and environmental interests. Currently, conservation of energy resources has become a global priority. On the other hand, given the dizzying demand for energy, has led specialists to find new techniques, such as renewable energies (solar, wind and geothermal). The present work is a contribution, by numerical simulation, to the study of heat transfer in flat solar collectors. On the basis of some experimental data, several simulation calculations have been carried out in order to determine the influencing parameters allowing better performance of the sensors and ensuring a good homogeneity of the temperature distributions. Based on the observation that, due to the low thermophysical properties of the air used as heat transfer fluid, solar air collectors rather give poor yields. It has been found very useful to have ‘baffling’ obstacles of various shapes and forms in the solar collector duct. This increases the thermal transfer of a coolant, which clearly improves the thermal efficiency of the solar air collector. This article consists mainly of studying the effects on heat transfer of turbulent forced convection by baffles of zigzag shapes, placed in a rectangular channel, using the finite volume method. The pressure-velocity coupling has been processed by the SIMPLEC algorithm. The results are presented in terms of the average Nusselt number and temperature field for different positions.

The airflow through a two-dimensional horizontal rectangular cross-section channel in the presence of two baffles has been numerically examined and analyzed in the steady turbulent regime. The baffles were of the zig-zag type or plane one. The calculations are based on the finite volume approach and the average Navier–Stokes equations along with the energy equation, have been solved using the SIMPLE algorithm. The nonuniform structured quadrilateral-type element mesh is used in this study. The fluid flow patterns represented for Reynolds numbers based on the hydraulic diameter of the channel ranging from 5000 to 20 000. Effects of various Reynolds number values on flow fields, dimensionless axial velocity profiles, as well as local and average friction coefficients in the test channel is presented. The obtained results show that the flow structure is characterized by strong deformations and large recirculation regions. In general, the fluid velocity and skin friction loss rise with the increase in the flow rate and hence the Reynolds number.

This article considers designing of a renewable electrical power generation system for self-contained homes away from conventional grids. A model based on a technique for the analysis and evaluation of two solar and wind energy sources, electrochemical storage and charging of a housing area is introduced into a simulation and calculation program that aims to decide, based on the optimized results, on electrical energy production system coupled or separated from the two sources mentioned above that must be able to ensure a continuous energy balance at any time of the day. Such system is the most cost-effective among the systems found. The wind system adopted in the study is of the low starting speed that meets the criteria of low winds in the selected region under study unlike the adequate solar resource, which will lead to an examination of its feasibility and profitability to compensate for the inactivity of photovoltaic panels in periods of no sunlight. That is a system with fewer photovoltaic panels and storage batteries whereby these should return a full day of autonomy. Two configurations are selected and discussed. The first is composed of photovoltaic panels and storage batteries and the other includes the addition of a wind system in combination with the photovoltaic system with storage but at a higher investment cost than the first. Consequently, this result proves that is preferable to opt for a purely photovoltaic system supported by the storage in this type of site and invalidates the interest of adding micro wind turbines adapted to sites with low wind resources.