Towards agro-environmentally sustainable irrigation with treated produced water in hyper-arid environments

Supplementary data: Supplementary data to this article is:available at https://ars.els-cdn.com/content/image/1-s2.0-S0378377420313408-mmc1.zip (338B).National Priorities Research Programme (NPRP) grant from the Qatar National Research Fund (QNRF), grant reference number NPRP8-1115-2-473

Procédure numérique pour la convection naturelle bidimensionnelle: Validation sur une géométrie rectangulaire

Cet article est le premier d'une série d’applications numériques consacrées à la validation d’une procédure numérique basée sur les différences finies et mise au point pour des problèmes bidimensionnels de convection naturelle en milieu confiné (principalement cylindrique). Dans un premier temps, on considère une géométrie rectangulaire et chauffée par le bas. On s’intéresse alors aux effets du nombre de Rayleigh et à l’influence de l’inclinaison de la cavité par rapport à l’horizontale sur la structure de l’écoulement et le transfert de chaleur

A fast computational model to the simulation of non-isothermal mold filling process in resin transfer molding

International audienceThe numerical simulation of mass and heat transfer model for the curing stage of the resin transfer molding (RTM) process is known as a useful method to analyze the process before the mold is actually built. Despite the intense interest in the modeling and simulation of this process, the relevant work is currently limited to development of flow models during filling stage. Optimization of non-isothermal mold filling simulation time without losing the efficiency remains an important challenge in RTM process. These were some reasons that motivate our work; namely the interested on the amelioration of the performance of RTM simulation code in term of execution time and memory space occupation. Our approach is accomplished in two steps; first by the modification of the control volume/ finite element method (CV/FEM) and second by the implementation in the modified code of an adapted conjugate gradient algorithm to the compressed sparse row storage scheme. The validity of our approach is evaluated with analytical results and excellent agreement was found. The results show that our optimization strategy leads to maximum reduction in time and space memory. This allows one to deal with problems with great and complex dimensions mostly encountered in RTM application field, without interesting in the constraint of space or time

A New Model for the Simulation and Improvement of Resin Transfer Molding Process

International audienceIn the current work, first of all, a general theoretical two-phase model was proposed to simulate the flow in the resin transfer molding RTM. This model has been widely used in geologic media and petroleums reservoirs and satisfied results have been given. The similarity between these medium and our composite domain either in heterogeneity or in fluid flow has motivated this choice. Based on multiphase darcy’s law, the model has been developed tosimulate the saturation distribution for two compressible immiscible phases which are resin and the air, it may control the formation of the void in composite material. Then, a particular case of the model was simulated numerically which is well known as the buckely-levrett model. Using the first time the control volume-finite element CV/FEM method, the results of this study agree qualitatively with experimental and numerical findings

Assessing circularity of multi-sectoral systems under the Water-Energy-Food-Ecosystems (WEFE) nexus

The Multi-Sectoral Water Circularity Assessment (MSWCA) is a methodological framework developed for circularity assessment of the Water-Energy-Food-Ecosystems nexus. It involves five methodological steps and includes an indicators list for the selection of case specific indicators. This study expands the MSWCA to provide a systematic approach for selecting indicators, considering system’s circular actions and multi-functionality, the capture of implemented changes, the three CE principles and the Sustainable Development Goals. Furthermore, this study differentiates between benchmark and dynamic circularity assessment and applies the expanded MSWCA in a water system of the HYDROUSA H2020 project. The benchmark assessment indicates that the HYDROUSA system achieves a 75% increase of water circularity, 76-80% increase of nutrients circularity and 14% reduction of operational `carbon footprint compared to the baseline scenario. The dynamic assessment highlights that additional measures can improve the system’s circularity performance (e.g. water circularity can reach 94%) and mitigate risks occurring from uncontrollable changes