Large eddy simulations (LES) of the flow past a wind turbine with and without tower and nacelle have been performed at 2 tip speed ratios (TSR, ), λ=3 and 6, where the latter corresponds to design conditions. The turbine model is placed in a virtual wind tunnel to reproduce the “Blind test 1” experiment performed at the Norwegian University of Science and Technology (NTNU) closed‐loop wind tunnel. The wind turbine was modeled using the actuator line model for the rotor blades and the immersed boundary method for the tower and nacelle. The aim of the paper is to highlight the impact of tower and nacelle on the turbine wake. Therefore, a second set of simulations with the rotating blades only (neglecting the tower and nacelle) has been performed as reference. Present results are compared with the experimental measurements made at NTNU and numerical simulations available in the literature. The tower and nacelle not only produce a velocity deficit in the wake but they also affect the turbulent kinetic energy and the fluxes. The wake of the tower interacts with that generated by the turbine blades promoting the breakdown of the tip vortex and increasing the mean kinetic energy flux into the wake. When tower and nacelle are modeled in the numerical simulations, results improve significantly both in the near wake and in the far wake.

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The access to water is critical in agricultural and livestock production.In the dry season, the water supply systems are under stress and have placed the region of La Mesa de Los Santos(Santander-Colombia) as susceptible to economic impacts due towater shortages, mainly caused by high demand ingrowth population, agriculture and the poultry production.Currently, the poultry production suffers from water shortages and has beensuppliedwith liquid in tanker trucks duringthe dry season, presenting a significant added cost to the farmers. The implementation of a rainwater-harvesting (RWH) system could reduce the water stress on the poultry industrial production of the region. The main objective of this research was to develop a mathematical model to identify the numbers of poultry grown cycles that a rainwater harvesting (RWH) system could potentially feed in an average year of precipitations. The analyses performed here considered daily rainfall data ranged from 2010 to 2018 obtained from the weather stations in La Mesa de Los Santos. The results of this research can be helpful to the entrepreneurs and policymakers by evaluating the importance of water management and the opportunity to take advantage of rainwater as a resource for sustainable poultry production, currently an important alternative to the value chain in the agricultural, livestock and industrial sector of the region.

Entre el 11 y 13 de noviembre de 2020, en plena pandemia, se realizó la versión número 6 del Coloquio de matemáticas en conjunto con el II encuentro Internacional de Matemáticas Aplicadas. Esta versión del coloquio fue realizada mediante la utilización de espacios virtuales realizando transmisión streaming de las charlas y conferencias por canales de Youtube. Esta editorial hace un recuento de los temas que se trataron.