Abstract

International Journal of Numerical Methods for Calculation and Design in Engineering (RIMNI) contributes to the spread of theoretical advances and practical applications of numerical methods in engineering and other applied sciences. RIMNI publishes articles written in Spanish, Portuguese and English. The scope of the journal includes mathematical and numerical models of engineering problems, development and application of numerical methods, advances in software, computer design innovations, educational aspects of numerical methods, etc. RIMNI is an essential source of information for scientifics and engineers in numerical methods theory and applications. RIMNI contributes to the interdisciplinar exchange and thus shortens the distance between theoretical developments and practical applications.

Desde 1985 la Revista Internacional de Métodos Numéricos para Cálculo y Diseño en Ingeniería (RIMNI) contribuye a la difusión en castellano, portugués e inglés de los desarrollos teóricos y aplicaciones prácticas de los métodos numéricos, tanto en relación con su utilidad como instrumentos de cálculo y análisis para el ingeniero y el científico, como en aspectos que inciden en las nuevas tecnologías de diseño y proyecto de producción y procesos en ingeniería. La revista abarca áreas diversas, tales como: modelos matemáticos y numéricos de problemas de ingeniería, desarrollo y aplicaciones de los métodos numéricos, nuevos avances en temas de software, innovaciones en el campo del diseño por computador, aspectos didácticos de los métodos numéricos, etc. La revista constituye una fuente de información imprescindible para ingenieros y científicos sobre innumerables temas relacionados con los métodos numéricos y sus aplicaciones, contribuyendo a promover la transferencia de conocimiento interdisciplinar y, por consiguiente, a acortar la distancia que existe entre los desarrollos teóricos y las aplicaciones concretas.

Abstract

This work details the development of a computational platform in joint collaboration between the Italian National Agency for New Technologies, Energy and Sustainable Economic Development (enea) and the University of Bologna (unibo). The platform is based on the open-source SALOME software that integrates the CATHARE system code for nuclear safety, FEMUS and OpenFOAM CFD codes in a unique framework, with efficient methods for data exchange. The computational platform has been used to simulate complex multiscale and multiphysics systems, such as the tall-3d facility, with a defective boundary condition approach on overlapping domains. The tall-3d experimental facility has been realized with the purpose of providing reference results to be used for both standalone and coupled System Thermal-Hydraulic (STH) and Computational Fluid Dynamic (CFD) code validation. The transient phenomenon of unprotected loss of lead-bismuth eutectic (LBE) flow that has been experimentally simulated at tall-3d is here studied. The system code is used to simulate the tall-3d apparatus while the CFD code is used to get a better insight into the fluid streaming occurring in the main tank component and improve the system code predictions. A flow transition from forced to natural convection is used to validate the codes and the platform ability to reproduce the experimental data.

Abstract

In this work the thermal-hydraulics and neutronics behavior of a Lead Fast Reactor (LFR) core is investigated evaluating the power generation distribution taking into account the local temperature field. The temperature field is evaluated using the CFD finite element code FEMuS and exchanged with the multiscale neutron code DONJON-DRAGON, which interpolates the macroscopic cross-sections according to the local temperature field and local lead density distribution. As a result, the neutron flux changes and defines a new power density distribution which is used to update the temperature field into the CFD code. The coupling between neutron and CFD codes is achieved through their inclusion into the numerical platform SALOME. The numerical libraries MED, included into the SALOME platform, are used to exchange data run-time between FEMuS and DONJON.

Abstract

Abstract

Lubrication is vital to improve performance, efficiency and durability in transmissions; it serves to minimize wear, noise, vibration and friction. The proper functioning of lubricated transmissions relies on interactions amongst a wide range of physical phenomena (contact dynamics, fluid-structure interaction and heat transfer) operating at different spatial and temporal scales. A lubricated transmission model is proposed in this work to obtain accurate information regarding all physical domains and the coupling thereof to quantify performance, efficiency and durability. The model consists of a thermo-elastically coupled flexible multibody model for the gear pair and a Thermo-Elasto-Hydrodynamic Lubrication (TEHL) model for the lubricant, both based on first principle modelling to ensure high fidelity.