Eulerian model and analysis of the impact of physical parameters on evaporative cooling by a water spray
Modèle eulérien et impact de paramètres physiques sur le refroidissement évaporatif d'un spray de gouttelettes d'eau
Résumé
The use of a water spray permits the evaporative cooling with the water droplet evaporation. The study of a two-phase flow is really complex due to a lot of parameters influencing the current of the droplets (flow velocity, temperature, relative humidity, characteristics of the droplets…). There are also numerous physical phenomenons which play an important role: evaporation, dispersion, sedimentation, collision, deposit… This paper presents the development of an Eulerian model simulating the injection of water droplets in an air flow. This model is based on the use of three thermodynamical variables: the liquid potential temperature, the sum of specific humidity for vapor and water droplets, and the number of droplets. The droplet evaporation is developed in the model and coupled with a Gaussian model to represent droplet dispersion. Results are first presented, then are compared to experimental measurements. Good similarities are observed on the air cooling. Moreover, parametric analyses are performed in order to gain insight into the impact of some parameters (relative humidity, water mass flow rate, droplet size).
Domaines
Sciences de l'environnement
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