Search results for "Computational Fluid Dynamics"
showing 10 items of 179 documents
Experimental and Numerical Analysis of a Cross-Flow Turbine
2016
An important component of the management cost of aqueducts is the energy costs. Part of these costs can be recovered by transforming some of the many existing energy dissipations into electric energy by means of economical turbines. This paper describes an experimental study that has been carried out in order to (1) test the performance of an economical cross-flow turbine that maintains high efficiency within a large range of water discharges, and (2) validate a new approximate formula relating main inlet velocity to inlet pressure. It is demonstrated that the proposed formula, on the basis of some simplifying assumptions, exactly links inlet velocity to inlet pressure with any possible geo…
Computational fluid dynamics and its application to transport processes
2007
Fluid transport behaviour is of great importance within the chemical process industry and in biotechnology. The complexity of this behaviour, reflected in the nature of the fundamental partial differential equations which describe it analytically, means that it has to be treated by numerical methods. In this paper the basic equations are given, and the approaches necessary to treat laminar and turbulent flows are carefully explained. As digital computers have increased in size, so has the comprehensiveness of the problems which can be treated, and the development of typical computer programs is described. Problems of accuracy and experimental validation are also surveyed, and it is shown th…
Impact of wind speed on ventilation performance within a container installed with photovoltaic inverter
2017
Abstract PV inverter needs proper ventilation for reducing the heat dissipation of the electronic components. In this work, a container installed with PV inverter is considered with different configurations of cooling channels within the container for ventilation analysis. Typically, high capacity PV inverters are installed inside the container and therefore inverters, are not experiencing external wind effects and it depends on the configuration of cooling channels. In this work, the main cooling channel is located at the top of the inverter; inlet and outlet ventilation holes are located on the side of cross ventilation. They help in analyzing the cooling design, dependent on site specifi…
Fire safety investigation for road tunnel ventilation systems – An overview
2014
Abstract In recent years, research activities about fire events in tunnel have received a significant impulse, especially after several accidents. The Computational Fluid Dynamic (CFD) has a fundamental role about. Researchers have spent resources on various topics involving numerical tools as the performance of a ventilation system, the influence of this on the air flow motion in the tunnel or the methods for fire schematization, fire-induced smoke characterization, turbulence models, etc. One of the main phenomena to consider for the safety when a fire occurs in a tunnel is the possibility of the fire-induced smoke to rise the tunnel (backlayering). A well-designed ventilation system shal…
Coupling CFD with a one-dimensional model to predict the performance of reverse electrodialysis stacks
2017
Abstract Different computer-based simulation models, able to predict the performance of Reverse ElectroDialysis (RED) systems, are currently used to investigate the potentials of alternative designs, to orient experimental activities and to design/optimize prototypes. The simulation approach described here combines a one-dimensional modelling of a RED stack with a fully three-dimensional finite volume modelling of the electrolyte channels, either planar or equipped with different spacers or profiled membranes. An advanced three-dimensional code was used to provide correlations for the friction coefficient (based on 3-D solutions of the continuity and Navier-Stokes equations) and the Sherwoo…
CFD simulations of dense solid–liquid suspensions in baffled stirred tanks: Prediction of solid particle distribution
2013
Abstract Industrial tanks devoted to the mixing of solid particles into liquids are often operated at an impeller speed N less than Njs (defined as the lowest speed allowing the suspension of all particles): under such conditions the distribution of solid-particles is very far from being homogeneous and very significant concentration gradients exist. The present work is devoted to assessing the capability of Computational Fluid Dynamics (CFD) in predicting the particle distribution throughout the tank. The CFD model proposed by Tamburini et al. [58] and successfully applied to the prediction of the sediment amount and shape was adopted here to simulate the particle distribution under partia…
Steady State and Dynamic Models of Multistage Flash Desalination: A Review
2010
This article focuses on a review of literature studies on steady state and dynamic modeling of the multistage flash desalination process (MSF). The review shows that both steady state and dynamic models are based on lumped parameter approach. Differences in literature models are found in the assumptions used to model the flashing stage in addition to the correlations used to determine the heat transfer coefficients, thermodynamic losses, thermodynamic and transport properties. Interestingly, literature indicates a rapid progress made in software used for coding and solution of the model equations. The review shows a limited number of literature models for the internals of the flashing stage…
Modeling and simulation of dense cloud dispersion in urban areas by means of computational fluid dynamics
2011
Abstract The formation of toxic heavy clouds as a result of sudden accidental releases from mobile containers, such as road tankers or railway tank cars, may occur inside urban areas so the problem arises of their consequences evaluation. Due to the semi-confined nature of the dispersion site simplified models may often be inappropriate. As an alternative, computational fluid dynamics (CFD) has the potential to provide realistic simulations even for geometrically complex scenarios since the heavy gas dispersion process is described by basic conservation equations with a reduced number of approximations. In the present work a commercial general purpose CFD code (CFX 4.4 by Ansys®) is employe…
Analysis of the bubbling behaviour of 2D gas solid fluidized beds
2008
Abstract In the field of gas–solid fluidization, bubbles, and all features regarding them, have a very great importance, as they significantly affect the process performance. Numerous experimental studies on bubbles, and their formation, evolution, and properties, have been performed in the past. These investigations appear particularly difficult, due to the nature of these systems, since the gas phase is distributed in both the bubble and the emulsion phase. Several experimental approaches have been developed to tackle this study. Among these, the Digital Image Analysis Technique purposely developed in Part I of the present work, based on the use of a video camera for monitoring the phenom…
Optimization of a Vehicle Shape by CFD Code
2005
In this paper, fluid dynamics simulations have been executed using a CFD (Computational Fluid Dynamics) commercial code, on a Maserati Biturbo mod. 222 - 1988. At first some surfaces are optimised, choosing the more important ones for the reduction of the resistance, by a manual variation of their geometry, hence a large surface is optimised in an automatic way, by means of an own software, developed in the MatLab environment, returning the optimised surface according to a specific objective function (the resistance in this paper). The aerodynamics resistance results are given under the form of aerodynamics penetration coefficient CD, taking into account the vehicle shape effect, the speed,…