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If transport is an essential means for the development of the economy, society and its mobility, it has the drawback of leading to significant atmospheric pollution. As traffic density is very high in large cities, air pollution is amplified by the various means of transport resulting from the combustion of fossil fuels. Urban air pollution is mainly caused by vehicles generating emissions harmful to human health. Our objective of this work is to analyze a strategy to eliminate or reduce the emission of these pollutants (NOx, CO, CO2) during combustion. This strategy aims to explore a clean energy source alternative to fossil fuels. This approach consists of completely replacing the internal combustion scalar with the engine powered by fuel cells using hydrogen. This motivates decision makers to choose hydrogen as an alternative fuel to protect the urban environment and the health human from air pollution. This study shows that it is possible to perfectly mitigate pollutants from urban transport systems by using a PEMFC as an alternative clean energy source. Analyze a strategy to eliminate or reduce the emissions of these pollutants (NOx, CO, CO2) during the combustion of full fossil fuel in vehicle engines. This strategy aims to exploit the energy vector represented by hydrogen in order to save human life in more populated areas and protect the environment. The pressure, temperature and concentration of each species (O2, H2 and H2O) are obtained from the resolution of the electrochemical model coupled to the dynamic model, which we do not present here.

The environmental and economic objectives for the reduction of fuel consumption and reduction in the polluting emissions are always of crucial news. Thus, the elucidation of new techniques of combustion using the diffusion flame (more secure) in a confined environment and the comprehension of the involved physical phenomena remains of capital challenge. The dilution of the combustion air by CO 2 has confirmed its technological interest; the objective of this work is to quantify numerically the polluting emissions in a turbulent diffusion flame. The air is diluted by CO 2 and attention has been paid to its thermal and chemical effects on the internal structure of the flame. It is found that CO 2 addition reduces flame temperature by both thermal and chemical effects. Most of the emissions are also reduced by CO 2 increasing in the air.

We develop the natural iteration method (NIM) in the cluster variation method (CVM) using the congruence between input and output maximum cluster probabilities in the procedure of iteration. In this method, the effective chemical potential $$ \upmu_{i}^{*} $$ is not necessarily fixed, and one can calculate the equilibrium in a certain grand potential Ω. This property is absent in the cluster variation method using the natural iteration method or the Newton-Raphson (N-R) method. When the new method is used, the calculations of binary phase diagrams for first-order transitions are easy, and one can obtain high precision results for CVM calculations in a short period of time using ordinary micro-computers. We illustrate this development by its application in $$ {\text{A1/L1}}_{ 0} / {\text{L1}}_{ 2} $$ binary phase diagram.

Natural convection flow past a vertical porous plate in a porous medium is studied numerically, by taking into account the Dufour and Soret effects. The similarity equations of the problem considered are obtained by using usual similarity technique. This system of ordinary differential equations, which are solved numerically by using the Nachtsheim -Swigerst hooting iteration technique together with a sixth order Runge-Kutta integrations scheme. The results show that Soret and Dufour effects do not appreciably influence the velocity, temperature and concentration fields, but rather only tend to increase the mass and energy flux due to the added contributions.