**4. Conclusions**

Heat-transfer coefficients are important parameters in the thermal modelling of a building and significantly influence the required air conditioning. The complexity of calculating these coefficients requires the use of CFD techniques that are not available to all users, which justifies the calculation of correlations that depend on the geometric parameters of a 2D enclosure under forced convection. We found that the CFD results are similar to those obtained using correlations for the flat plate model. The latter has the advantage of being velocity-independent in the proximity of the walls and is only dependent on the air speed at the inlet, which is known.

Another aspect highlighted in this study is the calculation of a correction factor that can be used when the wall temperatures are different. In addition, we obtained a correlation of the correction factor for each topology, which correct for the heattransfer coefficients when all of the walls are at the same temperature.

Thus, our results indicate that the variables with the highest influence on the heat-transfer coefficients are the number of air changes in an enclosure followed by the size of the inlet.

## **Acknowledgements**

This work is linked to two research projects, the first, and most socialising, is the project of National Plan "The air.es" entitled "Numerical modeling of combined heat inside buildings aeraulics oriented design eco-efficient "(MTM2012-36124- C02-00). This project is developed in collaboration with the research group FQM120 "Mathematical Modelling and Simulation of Environmental Systems", University of Sevilla.

### **Nomenclature**


*A New Forced Convection Heat Transfer Correlation for 2D Enclosures DOI: http://dx.doi.org/10.5772/intechopen.99375*

