Search results for " Simulation"
showing 10 items of 4034 documents
Power Quality Savings with Controlled Fault-Tolerant Power Converters
2011
Power quality is simply the interaction of electrical power with electrical equipments. If electrical equipments operate correctly and reliably without being damaged or stressed, a suitable level of power quality is assured. On the other hand, if the electrical equipment malfunctions, is unreliable, or is damaged during normal usage, power quality is poor and probably the economical loss could be preeminent over the technical one. In the scenario of the Distributed generation power quality issues will be more- over important because an higher dissemination of power conditioning equip- ment will be requested and this obviously will increase the sources of vulnera- bility for the electrical s…
Structural verification and manufacturing procedures of the cooling system, for DEMO divertor target (OVT)
2019
The paper presents the design activities and testing plan of a vertical target mock-up, developed within the pre-conceptual design phase for DEMO Work Package DIV-1 “Divertor Cassette Design and Integration” - EUROfusion Power Plant Physics & Technology (PPPT) program. Activities concerning the Divertor Outboard Vertical Target cooling mock-up are presented in term of CAD model, thermal-hydraulic numerical simulation, structural analysis, structural integrity verification and manufacturing procedure. Moreover, the mechanical dimensions of support systems for Plasma Facing Components (PFCs), manifold and diffuser have been analyzed in detail, in order to avoid structural fault during the tes…
Modelling biological and chemically induced precipitation of calcium phosphate in enhanced biological phosphorus removal systems
2011
The biologically induced precipitation processes can be important in wastewater treatment, in particular treating raw wastewater with high calcium concentration combined with Enhanced Biological Phosphorus Removal. Currently, there is little information and experience in modelling jointly biological and chemical processes. This paper presents a calcium phosphate precipitation model and its inclusion in the Activated Sludge Model No 2d (ASM2d). The proposed precipitation model considers that aqueous phase reactions quickly achieve the chemical equilibrium and that aqueous-solid change is kinetically governed. The model was calibrated using data from four experiments in a Sequencing Batch Rea…
Flow and Heat Transfer in Corrugated Passages: Direct and Large Eddy Simulation and Comparison with Experimental Results
1993
Direct and large-eddy numerical simulations are presented for the transitional and turbulent flow with heat transfer in corrugated passages, representative of compact heat exchangers such as rotary air preheaters (regenerators), at Reynolds number ranging from 103 to 104. Pressure drop and heat transfer results are compared with wind-tunnel experimental data; the agreement is quite satisfactory, and superior to that obtained by more traditional methods.
On the influence of curvature and torsion on turbulence in helically coiled pipes
2014
Turbulent flow and heat transfer in helically coiled pipes at Ret=400 was investigated by DNS using finite volume grids with up to 2.36×10^7 nodes. Two curvatures (0.1 and 0.3) and two torsions (0 and 0.3) were considered. The flow was fully developed hydrodynamically and thermally. The central discretization scheme was adopted for diffusion and advection terms, and the second order backward Euler scheme for time advancement. The grid spacing in wall units was ~3 radially, 7.5 circumferentially and 20 axially. The time step was equal to one viscous wall unit and simulations were typically protracted for 8000 time steps, the last 4000 of which were used to compute statistics. The results sho…
An evaluation of the environmental factors for supply chain strategy decisions using grey systems and composite indicators
2020
[EN] The purpose of this work is to assess the importance of environmental factors in a supply chain with four partners as a preliminary step to select the competitive strategies and objectives. To achieve this purpose, a real case study was carried out in a footwear supply chain, in which two approaches were used: the grey system theory and uncertainty analysis tools for composite indicators. In order to validate both approaches, a seven-phase research methodology was developed and applied to our case study. In addition, the priorization of environmental factors was calculated individually for each partner. The results allow managers to establish the competitive strategy that best suits th…
Aprendizaje de los fundamentos de la probabilidad apoyado en las TICs
2012
La red puede utilizarse como una herramienta docente más en Estadística, ya que en ella se puede acceder a numerosos recursos que pueden incorporarse a la docencia. En este artículo se describe un proyecto de integración de las denominadas simulaciones interactivas en una de las ramas de la Estadística en las que se pueden emplear: la probabilidad. El uso de estos recursos permite al alumno aprender de su propia experiencia y visualizar los conceptos estadísticos, lo que contribuye a mejorar su proceso de aprendizaje.
Modeling Marginalization: Emergence, Social Physics, and Social Ethics of Bullying
2020
In this paper, we outline the construction and initial simulation experiment results of the Marginalization model (MARG). We experiment under different group parameters because the theoretical paradigm we follow views bullying as a result of social processes. Our primary research question explores the possibility of bullying emergence as agents select interaction partners in a university setting. Based on the simulated process, our results take indications of the stress of marginalization in a student group as a proxy for emer-gent marginalization. MARG simulates two types of interactions between pairs of students: forced and hang-out interactions. In the latter, students decide whether to …
Modeling and Analysis of a New Process for Pyruvate Production
2005
Early process development is crucial for the economic and environmental performance of a final production process. A new process for the production of pyruvate is presented as a case study to show how process modeling and an analysis of the results regarding economic and environmental aspects improves the understanding of the process, its cost structure, and its environmental impact. It also enables the quantification of process improvements and the comparison of alternative designs. The model of the pyruvate production shows how strain and fermentation improvements propagate through the process and affect its economic and environmental performance. The comparison of two alternative purific…
Modelling the transient behaviour of a MED-TVC plant for coupling with CSP
2015
In this paper a dynamic model for the MED-TVC process has been developed and valided by a comparison with data from a real plant situated in Trapani, Italy, composed by 12 effects with parallel-feed configuration and equipped with a medium-pressure steam vapour ejector.