Search results for " CFD."

VISUALIZATION APPROACHES FOR STIRRED TANK BIOREACTORS

2019

Computational Fluid Dynamics (CFD) is the analysis of fluid behaviour employing numerical solution methods. Using CFD it is possible to analyse simple and complex fluid-gas, fluid-fluid or fluid-solid interactions. Fluid dynamics is described with laws of physics in the form of partial differential equations also known as Navier-Stokes equations. Sophisticated CFD solvers transform these laws into algebraic equations which are solved by numerical methods. In this paper Ansys CFX and Fluent analysis systems as research methods are used to visualize flow patterns in a stirred tank bioreactor. The results obtained are informative and can be used to improve the yield of biomass. CFD analysis ca…

Influence of the porosity profile and sets of Ergun constants on the main hydrodynamic parameters in the trickle-bed reactors

2014

Abstract The Eulerian multiphase code has been applied for the comparative simulation of the experimental results obtained for varying flow rates of both fluid phases and for systems of various physicochemical properties used in the laboratory trickle-bed reactor (TBR). Therefore six different radial porosity profiles and three sets of the Ergun constants used in the relations defining the interphase momentum exchange have been implemented into the CFD code. The mean relative error of the pressure drop and of the averaged holdup as well as the standard deviation determined with respect to the experiments have been used as the criterion for the validation of the theoretical model. These valu…

On the hydraulic behaviour of ITER Shield Blocks #14 and #08. Computational analysis and comparison with experimental tests

2016

Abstract As a consequence of its position and functions, the ITER blanket system will be subjected to significant heat loads under nominal reference conditions. Therefore, the design of its cooling system is particularly demanding. Coolant water is distributed individually to the 440 blanket modules (BMs) through manifold piping, which makes it a highly parallelized system. The mass flow rate distribution is finely tuned to meet all operation constraints: adequate margin to burn out in the plasma facing components, even distribution of water flow among the so-called plasma-facing “fingers” of the Blanket First Wall panels, high enough water flow rate to avoid excessive water temperature in …

CFD modelling of thin channels for direct and reverse electrodialysis

2012

The effect of Water on passive cooling systems in the Arab-Norman architecture of the Zisa Palace in Palermo

2019

This paper shows the theories argued by some historians with reference to the working of natural water passive cooling systems employed in the Zisa Complex. Albeit such theories are seminal attempts to understand passive water systems, they have no scientific evidence. This study instead concentrates on a more rigorous treatment that enabled to set up a robust framework for designing a historical water passive system such as the Salsabil, which in fact was conceived and developed in an empirical way. Several historical buildings of the Mediterranean and Middle Eastern architecture include relevant artefacts useful to control humidity and temperature through water passive systems . The archi…

Improving the rheometry of rubberized bitumen: experimental and computation fluid dynamics studies

2017

Abstract Multi-phase materials are common in several fields of engineering and rheological measurements are intensively adopted for their development and quality control. Unfortunately, due to the complexity of these materials, accurate measurements can be challenging. This is the case of bitumen-rubber blends used in civil engineering as binders for several applications such as asphalt concrete for road pavements but recently also for roofing membranes. These materials can be considered as heterogeneous blends of fluid and particles with different densities. Due to this nature the two components tends to separate and this phenomenon can be enhanced with inappropriate design and mixing. Thi…

A new methodology to evaluate the flying shape of a sail

2013

CFD simulations of spacer-filled channels for pressure retarded osmosis applications

2015

Different spacer features and operating conditions were investigated in order to identify a good compromise between concentration polarization and pumping power reductions.

Evaluation of the Thermodynamic Performance of the Traditional Passive Systems

2013

The energy consumption of buildings in urban areas is one of the greatest source of energy wasting and, consequently, of increasing of CO2 emission. Research is currently focused on the reduction of this consumption through the use of passive air-conditioning systems, that can be integrated with conventional systems and give rise to the so-called hybrid systems. Historically, these passive systems were developed in the Mediterranean and Middle East area. The research approach on this topic involves the application of design strategies and the development of computational tools and control systems. The development of the hybrid systems is the result of the synergy between current scientific …

PROGETTAZIONE E VERIFICA SPERIMENTALE DI UNA MICROTURBINA IDRAULICA PER L’INDUSTRIA ALIMENTARE

2014

In questo articolo sono descritte le attività di ricerca e sviluppo di una micro-turbina idraulica inserita all’interno di un macchinario che opera un nuovo processo di abbattimento della carica batterica applicabile nell’industria dell’imbottigliamento delle bevande. Peculiarità della turbina progettata è la geometria della palettatura della girante, dritta ed a sviluppo puramente assiale, che ne rende estremamente economica la realizzazione. Lo scambio di energia avviene grazie al moto vorticoso impresso al fluido (swirl) mediante opportuno posizionamento dei condotti di adduzione. Lo studio della turbina è stato condotto mediante classico approccio unidimensionale, mentre il dimensioname…