Multi-Cell Concept for Simulating Fires in Big Enclosures Using a Zone Model

1996 ◽  
Vol 14 (3) ◽  
pp. 186-198 ◽  
Author(s):  
W.K. Chow
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Temperature Distribution ◽  
Physical Properties ◽  
Flow Pattern ◽  
Layer Thickness ◽  
Zone Model ◽  
Smoke Layer

The multi-cell concept is applied to simulate fire in a big com partment with the zone model CFAST. The predicted physical properties of the smoke layer are used to justify the results, including the smoke layer tempera ture, smoke layer thickness and flows between each cell. Microscopic pictures of the flow pattern and smoke temperature distribution similar to the results pre dicted by the Computational Fluid Dynamics technique can be obtained. This idea is recommended to study fires in big enclosures.

scholarly journals Converting a food oven into a thermal sanitizer for Personal Protective Equipment against COVID-19: Computational Fluid Dynamics simulation

2021 ◽  
Author(s):  
Eleonora Bottani ◽  
Roberto Montanari ◽  
Andrea Volpi ◽  
Giulio Di Maria ◽  
Federico Solari ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Temperature Distribution ◽  
Personal Protective Equipment ◽  
Experimental Validation ◽  
Dynamics Simulation ◽  
Protective Equipment ◽  
Computational Fluid Dynamics Simulation ◽  
Food Sector ◽  
Know How

COVID-19 brought several management problems, and among these surely the topic of Personal Protective Equipment (PPE) turned out to be crucial. Indeed, in the light of mandatory measurements adopted by governments both for private individuals and companies, their demand has rapidly increased, thus generating shortages, increased waste and unbalanced prices. In response to that, many industrial fields offered their tools and know-how for trying to partly face this issue, and in this paper part of a solution of this kind is presented. Specifically, it is meant the redesign of a food oven produced by an Italian company operating in the food sector (Nilma S.p.A.) for thermal sanitization against the virus in question. In this paper, the simulation of the temperature distribution inside the chamber is simulated, with subsequent experimental validation at 95°C.

scholarly journals The Aerodynamics of a Diabolo

2021 ◽  
Author(s):  
Darren Jia
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Angular Momentum ◽  
Flow Pattern ◽  
High Spin ◽  
Angular Speed ◽  
Geometric Shape ◽  
Cfd Simulations ◽  
Resistive Torque ◽  
Computational Fluid Dynamics Cfd

Diabolo is a popular game in which the object can be spun at up to speeds of 5000 rpm. This high spin velocity gives the diabolo the necessary angular momentum to remain stable. The shape of the diabolo generates an interesting air flow pattern. The viscous air applies a resistive torque on the fast spinning diabolo. Through computational fluid dynamics (CFD) simulations it's shown that the resistive torque has an interesting dependence on the angular speed of the diabolo. Further, the geometric shape of the diabolo affects the dependence of torque on angular speed.

Effect of Zinc Pot Designs on Flow and Temperature Distribution in Hot-Dip Galvanizing Process

2016 ◽  
Vol 826 ◽  
pp. 99-104
Author(s):  
Guang Rui Jiang ◽  
Li Bin Liu ◽  
Huang Xiang Teng ◽  
Fang Qing Kong
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Temperature Distribution ◽  
Low Temperature ◽  
Zinc Level ◽  
Heating Power ◽  
Liquid Zinc ◽  
Base Case ◽  
Computational Fluid Dynamics Cfd ◽  
Temperature Liquid

s In this study, Computational Fluid Dynamics (CFD) was used to simulate the flow and temperature distribution in zinc pot of hot-dip galvanizing process. The flow and temperature distribution in a base-case zinc pot was compared to that in other two optimized zinc pots, one of which had a dam between ingot and snout and another one had a reduced heating power. The simulation shows that the dam impedes the flow of low temperature liquid zinc around zinc ingot to strip and increases the fluctuation of zinc level. By reducing the heating power, however, the fluctuation of zinc level could be suppressed.

Airflow Simulation of the Huge Telescope Assemble

2010 ◽  
Vol 439-440 ◽  
pp. 880-883
Author(s):  
Fu Zhao ◽  
Ping Wang ◽  
Yan Jue Gong ◽  
Yu De Liu ◽  
Hong Bin Xin
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Natural Convection ◽  
Temperature Distribution ◽  
Velocity Field ◽  
Three Dimensional ◽  
Horizontal Line ◽  
Air Velocity ◽  
Turbulent Airflow ◽  
Dynamics Method

With the three-dimensional computational fluid dynamics method, the airflow effects over the huge telescope assemble is investigated in this article. The distributing of velocity field and natural convection are studied by modeling and simulating the turbulent airflow of the huge telescope. Numerical simulations show the best observation direction is the 90o angle between the main optics axis and the horizontal line in which the air velocity distribution is the least. And the air temperature distribution and uniformity around the telescope are also provided by simulation.

scholarly journals Experimental and CFD Modelling: Impact of the Inlet Slug Flow on the Horizontal Gas–Liquid Separator

Energies ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 41
Author(s):  
Siong Lee ◽  
Thomas Choong ◽  
Luqman Abdullah ◽  
Mus’ab Abdul Razak ◽  
Zhen Ban
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Liquid Phase ◽  
Flow Pattern ◽  
Slug Flow ◽  
Cavity Formation ◽  
Cfd Modelling ◽  
Computational Fluid Dynamics Cfd ◽  
The Impact ◽  
Liquid Separator

For a gas-liquid separator sizing, many engineers have neglected the flow pattern of incoming fluids. The impact of inlet slug flow which impeded onto the separator’s liquid phase will cause a separator fails to perform when sloshing happened in the separator. To date, the study on verifying the impact of inlet slug flow in a separator remains limited. In this paper, the impact of inlet momentum and inlet slug flow on the hydrodynamics in a separator for cases without an inlet device were investigated. The experimental and Computational Fluid Dynamics (CFD) results of cavity formation and sloshing occurrence in the separator in this study were compared. A User Defined Function (UDF) was used to describe the inlet slug flow at the separator inlet. Inlet slug flow occurred at inlet momentum from 200 to 1000 Pa, and sloshing occurred in the separator at 1000 Pa. Both experimental and simulated results showed similar phenomena.

A fully coupled computational fluid dynamics and multi-zone model with detailed chemical kinetics for the simulation of premixed charge compression ignition engines

2005 ◽  
Vol 6 (5) ◽  
pp. 497-512 ◽  
Author(s):  
A Babajimopoulos ◽  
D N Assanis ◽  
D L Flowers ◽  
S M Aceves ◽  
R P Hessel
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Chemical Kinetics ◽  
Zone Model ◽  
Compression Ignition ◽  
Detailed Chemical Kinetics ◽  
Fully Integrated ◽  
Fully Coupled ◽  
Detailed Chemical ◽  
The Ideal

Modelling the premixed charge compression ignition (PCCI) engine requires a balanced approach that captures both fluid motion as well as low- and high-temperature fuel oxidation. A fully integrated computational fluid dynamics (CFD) and chemistry scheme (i.e. detailed chemical kinetics solved in every cell of the CFD grid) would be the ideal PCCI modelling approach, but is computationally very expensive. As a result, modelling assumptions are required in order to develop tools that are computationally efficient, yet maintain an acceptable degree of accuracy. Multi-zone models have been previously shown accurately to capture geometry-dependent processes in homogeneous charge compression ignition (HCCI) engines. In the presented work, KIVA-3V is fully coupled with a multi-zone model with detailed chemical kinetics. Computational efficiency is achieved by utilizing a low-resolution discretization to solve detailed chemical kinetics in the multi-zone model compared with a relatively high-resolution CFD solution. The multi-zone model communicates with KIVA-3V at each computational timestep, as in the ideal fully integrated case. The composition of the cells, however, is mapped back and forth between KTVA-3V and the multi-zone model, introducing significant computational time savings. The methodology uses a novel re-mapping technique that can account for both temperature and composition non-uniformities in the cylinder. Validation cases were developed by solving the detailed chemistry in every cell of a KIVA-3V grid. The new methodology shows very good agreement with the detailed solutions in terms of ignition timing, burn duration, and emissions.

Computational fluid dynamics with stents: quantitative comparison with particle image velocimetry for three commercial off the shelf intracranial stents

2015 ◽  
Vol 8 (3) ◽  
pp. 309-315 ◽  
Author(s):  
Pierre Bouillot ◽  
Olivier Brina ◽  
Rafik Ouared ◽  
Hasan Yilmaz ◽  
Karl-Olof Lovblad ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Flow Pattern ◽  
Laser Sheet ◽  
Time Lag ◽  
High Porosity ◽  
Velocity Reduction ◽  
Commercial Off The Shelf ◽  
Particle Imaging ◽  
Low Porosity

Background and purposeValidation of computational fluid dynamics (CFD) in stented intracranial aneurysms (IAs) is still lacking, to reliably predict prone to occlusion hemodynamics, probing, in particular, velocity reduction, and flow pattern changes. This study compares CFD outcome with particle imaging velocimetry (PIV) for three commercial off the shelf (COTS) stents of different material densities.Material and methodsThe recently developed uniform and high precision multi-time lag PIV method was applied to a sidewall aneurysm before and after implantation of three COTS stents with high, intermediate, and low material densities. The measured laser sheet flow patterns and velocity reductions were compared with CFD results and correlated with stent material density.ResultsVelocity reduction was in good agreement for unstented high and low porosity stented IA, while flow pattern change was fully matched for unstented and high porosity stented IA. Poor CFD–PIV matching in IA was found for intermediate porosity stents.ConclusionsCFD reproduced fully PIV measurements in unstented and high porosity stented IAs. With low porosity stents, CFD reproduced velocity reduction and high velocities close to the neck, while a marked mismatch on sluggish flow was found at the dome. CFD was unable to match PIV with intermediate porosity stents for which hemodynamic transition occurred.

Computational Fluid Dynamics Investigation of a High Temperature Waste Heat Exchanger Tube Sheet Assembly

2005 ◽  
Author(s):  
Michael A. Porter ◽  
Dennis H. Martens ◽  
Thomas Duffy ◽  
Sean McGuffie
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
High Temperature ◽  
Temperature Distribution ◽  
Carbon Steel ◽  
Gas Flow ◽  
Waste Heat ◽  
Thermal Reactor ◽  
Process Gas

Many modern Sulfur Recovery Unit (SRU) process waste heat recovery exchangers operate in high temperature environments. These exchangers are associated with the thermal reactor system where the tubesheet/tube/ferrule assemblies are exposed to gasses at temperatures approaching 3000°F. Because sulfur compounds are present in the process gas, the carbon steel tubesheet and tubes in the assembly will be deteriorated by sulfidation as the operating metal temperature rises above 600°F. Ferrule systems are used to protect the carbon steel from exposure to excessive temperatures. The temperature distribution in the steel tubesheet/tube/ferrule system is affected by process gas flow and heat transfer through the assembly. Rather than depend upon “assumed” heat transfer coefficients and fluid flow distribution, a Computational Fluid Dynamics (CFD) investigation was conducted to study the flow fields and heat transfer in the tubesheet assembly. It was found that the configuration of the ferrule installation has a large influence on the temperature distribution in the steel materials and, therefore, the possible sulfidation of the carbon steel parts.

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