In this work, a three-dimensional numerical simulation, accompanied by an experimental study, of the evaporation of one or more nonaligned liquid droplets deposited on a solid substrate and surrounded by air was produced. In addition to the central droplet, the behavior of other neighboring droplets was tracked. Evaporation of a single droplet S was compared with that of multiple droplets (a droplet C surrounded by four non-aligned droplets). The shielding effect exerted by the four droplets on the droplet C increases the life of the latter by 83% as compared to a single droplet. Evaporated flow of the droplet C is reduced by 58% compared to the case of the isolated droplet S. The droplets at the extremities evaporate faster (compared to the droplet C, the evaporated volume can increase up to 57%), since they have less interaction with nearby droplets. A geometric coefficient F characterizing the ratio of the distance separating two neighboring droplets, to the diameter of a droplet was introduced. The shielding effect decreases with the increase of F. For F greater than 5, the behavior of the extremity droplets tends towards that of a single droplet.

In this work, we present the validation of a numerical model of a greenhouse thermally in-sulated on three sides with a tomato crop. A CFD software (Ansys-Fluent) was used to solve the numerical model. The discrete ordinate model was included to solve the radiative trans-fer equation. The results of the numerical model were compared with the values of air tem-perature observations at different points in the greenhouse. Good agreement was obtained between the simulated and measured values, with coefficients of determination R2 = 0.77, R2 = 0.84, R2 = 0.99, and R2 = 0.89 for the temperatures of the points 10 cm, 80 cm, and 210 cm above the ground and the average temperature in the greenhouse, respectively. A third-order polynomial curve was drawn between the simulated and measured values of relative humidity in the greenhouse. These R2 values are 0.9786 and 0.7165, the simulated and measured relative humidity, respectively. The simulation results showed low velocity values with an average of 0.525 m/s located between 1.5 m and 2 m from the ground.

The present work presents a numerical study of the evaporation of a sessile liquid droplet deposited on a substrate and subjected to different heating configurations. The physical formulation accounts for evaporation, the Marangoni effect, conductive transfer in the support, radiative heating, and diffusion–convection in the droplet itself. The moving interface is solved using the Arbitrary Lagrangian–Eulerian (ALE) method. Simulations were performed using COMSOL Multiphysics. Different configurations were performed to investigate the effect of the heating conditions on the shape and intensity of the Marangoni circulations. A droplet can be heated by the substrate (different natures and thicknesses were tested) and/or by a heat flux supplied at the top of the droplet. The results show that the Marangoni flow can be controlled by the heating configuration. An upward Marangoni flow was obtained for a heated substrate and a downward Marangoni flow for a flux imposed at the top of the droplet. Using both heat sources generated two vortices with an upward flow from the bottom and a downward flow from the top. The position of the stagnation zone depended on the respective intensities of the heating fluxes. Controlling the circulation in the droplet might have interesting applications, such as the control of the deposition of microparticles in suspension in the liquid, the deposition of the solved constituent, and the enhancement of the evaporation rate.