An Evapotranspiration Evolution Model as a Function of Meteorological Variables: A CFD Model Approach

Abstract

The study of meteorological variables and evapotranspiration in open spaces using the three spatial dimensions represents a technical challenge since the high computational resources required only enable the problem to be addressed on a very small scale. This research sets forth a three-dimensional computational fluid dynamics numerical model, characterized by its simplicity, which allows problems to be addressed over large areas (scale of kilometres). Similarly, the corresponding design and software developments carried out allow for a more dynamic introduction of meteorological and evapotranspiration boundary conditions. In the numerical domain created, the Reynolds-Averaged Navier–Stokes equations are solved, supplemented by a multispecies model (to distinguish the movements of dry air, evapotranspiration and air humidity) and one of solar radiation. The numerical model was applied to a semi-arid area in southern Spain, obtaining the three-dimensional special evolution of evapotranspiration, temperature, air humidity and wind velocity, specifically concerning its variation in horizontal and vertical planes of the three-dimensional domain, as well as vertical profiles at discrete points.