Search results for "STIR"

Design and development of a new machine tool for continuous friction stir extrusion

2023

In the present paper the Continuous Friction Stir Extrusion process (CFSE), derived from the already known Friction Stir Extrusion (FSE), is proposed for effective solid-state recycling of metal scraps. A new dedicated machine tool was designed and developed. A Lagrangian implicit thermomechanical numerical model was set up and used to determine the proper ranges of the most relevant process parameters. An effective case study is proposed, involving the actual extrusion of a recycled wire in a continuous way. Metallurgical observations and mechanical characterization tests were carried out on the obtained specimen showing the potential of the process and its industrial feasibility.(c) 2023 …

Numerical Simulation of Friction Stir Welding by Natural Element Methods

2008

In this work we address the problem of numerically simulating the Friction Stir Welding process. Due to the special characteristics of this welding method (i.e., high speed of the rotating pin, very large deformations, etc.) finite element methods (FEM) encounter several difficulties. While Lagrangian simulations suffer from mesh distortion, Eulerian or Arbitrary Lagrangian Eulerian (ALE) ones still have difficulties due to the treatment of convective terms, the treatment of the advancing pin, and many others. Meshless methods somewhat alleviate these problems, allowing for an updated Lagrangian framework in the simulation. Accuracy is not affected by mesh distortion (and hence the name mes…

Meshless Simulation of Friction Stir Welding

2007

This paper encompasses our first efforts towards the numerical simulation of friction stir welding by employing a Lagrangian approach. To this end, we have employed a meshless method, namely the Natural Element Method (NEM). Friction Stir welding is a welding process where the union between the work pieces is achieved through the extremely high deformation imposed by a rotating pin, which moves between the two pieces. This extremely high strain is the main responsible of the difficulties associated with the numerical simulation of this forming process. Eulerian and Arbitrary Lagrangian-Eulerian (ALE) frameworks encounter difficulties in some aspects of the simulation. For instance, these ap…

Life Cycle Sustainability Assessment of a dish-Stirling Concentrating Solar Power Plant in the Mediterranean area

2021

Abstract Among the different renewable energy sources, solar energy shows the highest exploitation potential to satisfy a substantial portion of the worlds’ future energy demand, guaranteeing at the same time lower emissions than conventional energy providers. Much of this potential is usable thanks to Concentrating Solar Power (CSP) technologies, of which the dish-Stirling concentrator is the most efficient. Nevertheless, the production and installation phases of the dish-Stirling technology can have an environmental impact which motivated the assessment of the plant in the three dimensions of sustainability (environmental, economic and social). The present publication evaluated an existin…

Residence Time Distribution of Solid Particles in a High-Aspect Ratio Multiple-Impeller Stirred Vessel

2003

Despite its importance, experimental information on the Residence Time Distribution (RTD) of solid particles in continuous-flow stirred vessels is still scant. In this work, experimental data on particle RTD in a high-aspect-ratio vessel stirred by three equally-spaced Rushton turbines, was obtained by means of a special technique named Twin System Approach (TSA). Quite surprisingly, results indicate that, among the various possibilities that could have been devised (e.g. 6, or 3, or 1 ideal tanks in series), the flow model closest to reality for the particle phase, at least in the experimental range here investigated, is that of a single perfectly stirred vessel.

[Cèdula. 1692. 08. 12]

1731

Inclou també la Cèdula reial de 29 d'Abril de 1731 amb el nomenament de Don Manuel de Riovello Franco com a "Juez Conservador y Privativo" i dues cèdules anteriors, de 12 d'Agost de 1692 i de 10 de Setembre de 1697 Caplletra grav. Sign.: A-D2 Reclams

Cèdula, 1731, 04, 29

Inclou també la Cèdula reial de 29 d'Abril de 1731 amb el nomenament de Don Manuel de Riovello Franco com a "Juez Conservador y Privativo" i dues cèdules anteriors, de 12 d'Agost de 1692 i de 10 de Setembre de 1697 L'autor de la representació a Felip V, segons consta al final, datada el 18 de Març de 1729, és Don Francisco Amador y Azcutia Sense port. ni colofó, com a tít. el començament del text i part del final Caplletra grav Sign.: A-D2 Reclams

Por el comendador y religiosos del Real Convento de Nuestra Señora del Puig, sito en la Villa de este nombre. En el pleyto que sigue con el licenciad…

Signat al final: "Fabian Moros" Port. orlada Grav. xil. enmarcat de la Mare de Déu a la port Caplletra ornada al començament del text Sign.: [A]2, B-E2 Reclams

Historia del real monasterio de la SSma. Trinidad, religiosas de Santa Clara, ...

Grav. calc. abans de la port. i retrat calc. de Santa Isabel de Villena en p. 99: "Pasql. Moles del. et Stt. Vª" Sign. : *-****4, A-Hh4, I2 Notes a peu de p. - Reclams Capll. orn. , fris, vinyeta

Antiguo Monasterio del Santo Sepulcro de Basilianos, primitivos monges de España : ilustrado con los estudios de S. Domingo : critica exacta de las d…

Fris i caplltres ornades Sign.: [ ]4, A-K4 Notes a peu de p. - Reclams