Fiorenzo Ambrosino

The role of medium size facilities in the HPC ecosystem: the case of the new CRESCO4 cluster integrated in the ENEAGRID infrastructure

Medium size HPC clusters play an important role in the HPC landscape in that they provide both the training environment for system scalability and a flexible production field for a large class of numerical problems. In this poster we present CRESCO4, the latest medium size HPC cluster purchased by ENEA, in operation since few months. CRESCO4 is part of a family of HPC systems, all integrated within ENEAGRID, a large infrastructure for cloud computing, which includes all the computational facilities installed at several ENEA sites in Italy.

Investigation of Char–Slag Interaction Regimes in Entrained-Flow Gasifiers: Linking Experiments with Numerical Simulations

Entrained-flow gasifiers are characterized by operating conditions that promote ash migration/deposition onto the reactor walls, whence the ash is drained as a molten phase. Experimental investigation on ashes generated by full-scale plants suggested that both char entrapment inside the melt and carbon-coverage of the slag can occur. Because of the wide range of spatial and temporal scales involved in these phenomena, numerical simulation of the fate of the flying fine char particles is a very difficult task. Simulations based on a Eulerian large eddy simulation (LES) approach for the turbulent gas phase and a Lagrangian particle tracking (LPT) approach for the solid phase have been performed to explore, in a simplified flow configuration, near-wall particle segregation and the role of relevant parameters (in particular, particles’ inertia and slag layer restitution coefficient). Results of numerical simulations have been critically discussed with reference to the experimental observations. Numerical results confirm that near-wall accumulation of particles may be extensive, and promoted by large Stokes numbers and by small restitution coefficients.

Quasi real-time FEM calibration by 3D displacement measurements of large shaking table tests using HPC resources

Abstract The present paper concerns the implementation of a methodology aiming to achieve a quasi real-time calibration of Finite Element Models (FEMs) of large structural mock-ups during shaking table tests. The damage achieved after each test step is commonly evaluated by visual inspection, since running large numerical analyses or processing the experimental data for damage estimation with common computing resources is very time-consuming and in case of a prolonged stand-by the shaking tables oil temperature stability can be put at risk. On the other hand, the specimen damage level can be monitored through the modal parameters estimated using Finite Element Analyses (FEAs), but FEMs require to be calibrated to provide accountable results. In the proposed approach the FEM calibration was carried out using 3D motion data of a large number of passive markers. They were acquired and processed by a dedicated Displacement Data Processing (DDP) procedure combining the Savitzky-Golay filtering for data noise reduction and the convolution derivation approach for the extraction of the motion parameters. To obtain results in reasonable time between test steps (a few minutes) the methodology exploits the hardware and software resources available on the ENEA High-Performance Computing (HPC) system. Also, the proposed approach allowed to integrate within a single web interface the possibility to share the seismic experiments in real time, while providing updated FEM calibration at each step of the test sequence during the experimental session.

A Collaborative Environment for Web Crawling and Web Data Analysis in ENEAGRID.

In this document we provide an overview on the development and the integration in ENEAGRID of some tools able to download data from Web (Web Crawling), manage and display a large amount of data (Big Data), and extract from data relevant hidden information (Data Mining). We collected all these instruments inside the so called Web Crawling Project. Further, the corresponding environment, called Virtual Laboratory, is able to offer the possibility to use all these integrated tools remotely and by a simple graphical interface. A detailed description of the developed web application will be illustrated. Finally, some experimental results on the behaviour of the Web Crawling tool will be reported.

A Virtual Prototyping Platform to Improve CAE Analysis Workflow

This paper describes an experimental software system that allows interfacing a virtual immersive environment with Computer Aided Engineering CAE open source software aiming for improving and simplifying design process and results evaluation. System includes a middleware to execute jobs on HPC architectures and to compare results of server-class processors with GPGPU hardware. The main innovation of the overall system is the possibility to setup the CAE job directly inside the virtual reality platform speeding-up the entire process. User evaluations on selected case studies show how the use of a virtual environment may enhance the perception of engineers ideas during the design process. In addition, the use of a system that allows reconfiguring and relaunching the job simplifies setup of job configuration. Results also show that HPC hardware based on GPGPU offers a perceivable speedup for problems with an high number of nodes.