variavel0=<b>Antonio Cesar Silveira Baptista Silva</b> - antonio@labeee.ufsc.br Universidade Federal de Pelotas
<b>Jose Antonio Bellini Cunha Neto</b> - bellini@lmpt.ufsc.br Universidae Federal de Santa Catarina
<b>Roberto Lamberts</b> - lamberts@ecv.ufsc.br Universidae Federal de Santa Catarina
<b>Abstract.</b> This paper presents the first step on the development of the model of a spray used for evaporative cooling of buildings and of external environments. This kind of system is useful for conditioning big volumes of air when the climate conditions are favorable. The paper presents the results of a numerical analysis of the balances of heat, mass and momentum in order to model the effect of the evaporative cooling. Spray characteristics (water temperature, volume flow rate, output velocity, droplets diameter) are used to predict the thermal, mass and momentum exchanges and the evaporative cooling that results from these exchanges. The model used is based on discrete particles with separate flow originating a system of non-homogeneous differential ordinary equations of first order, solved by a mathematical CAD. The exchanges of heat and mass on the surface of the droplets are modeled using classical correlations for convection in moist air. At the end of the spray plume, volume flow rate, temperature and air humidity can be used directly to determine thermal comfort of building occupants or indirectly by coupling the model to a thermal simulation of buildings code.
<b>Keywords.</b> Evaporative cooling, Free stream jet, Droplet jet.