scholarly journals Mathematical Modeling and Simulation of Development of the Fires in Confined Spaces

2020 ◽  
Author(s):  
Ivan Antonov ◽  
Rositsa Velichkova ◽  
Svetlin Antonov ◽  
Kamen Grozdanov
Keyword(s):  
Mathematical Modeling ◽  
Fluid Mechanics ◽  
Dynamic Simulation ◽  
Turbulence Models ◽  
Solution Model ◽  
Computational Fluid Mechanics ◽  
Confined Space ◽  
Confined Spaces ◽  
Story Building ◽  
Over Time

The mathematical models of fire distribution in a confined space–in underground garages and in buildings—are described. Integral and computational fluid mechanics methods are used. The chapter presents the results of a fire simulation using the software Fluent. It uses Reynolds-type turbulence models of the Fire Dynamic Simulation or PyroSim graphical interface with a solution model describing a turbulence. For both cases, the pictures of the spread of fire and smoke over time in an atrium of an administrative building and a five-story building of the TUS were presented.

A Reliable Procedure for Testing the Accuracy of Numerical Algorithms in CFD and Heat Transfer

2001 ◽  
Author(s):  
V. Dakshina Murty
Keyword(s):  
Heat Transfer ◽  
Fluid Mechanics ◽  
Computational Mechanics ◽  
Numerical Algorithms ◽  
Turbulence Models ◽  
Nonlinear Problems ◽  
Computational Fluid Mechanics ◽  
Source Terms ◽  
Body Forces ◽  
Reliable Procedure

Abstract A reliable procedure for benchmarking of computer solutions in the fields of computational mechanics including computational fluid mechanics, heat transfer, and k-ε turbulence models is presented. The procedure consists of using assumed solutions to calculate the required source terms (which could be in the form of body forces for momentum equations) and use the resulting source terms as inputs to back calculate the displacements, velocities, temperature, etc. The procedure works especially well for nonlinear problems. Several examples are provided from fluid mechanics and heat transfer.

Some uses of direct solvers in computational fluid mechanics

1987 ◽  
Author(s):  
HARRY DWYER ◽  
KENICHI MATSUMO ◽  
SOKOL IBRANI ◽  
M. HAFEZ
Keyword(s):  
Fluid Mechanics ◽  
Computational Fluid Mechanics ◽  
Direct Solvers

USNCCM-11: Computational fluid mechanics for free and moving boundary problems

2013 ◽  
Vol 87 ◽  
pp. 1
Author(s):  
Rekha R. Rao ◽  
S.A. Roberts ◽  
David R. Noble ◽  
Patrick D. Anderson ◽  
Jean-Francois Hétu
Keyword(s):  
Fluid Mechanics ◽  
Moving Boundary ◽  
Computational Fluid Mechanics ◽  
Moving Boundary Problems ◽  
Boundary Problems

Study on Prediction and Assessment Methods of Outdoor Wind Environment of Residential District - Taking “Letian Home” in Leshan, Sichuan for Example

2011 ◽  
Vol 71-78 ◽  
pp. 3868-3873
Author(s):  
Li Jin Ma ◽  
Hong Juan Zou ◽  
Jia Shun Zhu
Keyword(s):  
Fluid Mechanics ◽  
Composite Index ◽  
Assessment Method ◽  
Assessment Methods ◽  
Assessment System ◽  
Outdoor Environment ◽  
Computational Fluid Mechanics ◽  
Analog Computation ◽  
Wind Environment ◽  
Residential District

According to the micro-climate environment outdoor of the region, wind environment outdoor which is under planning programming can be done analog computation using computational fluid mechanics PHOENICS software. A set of comprehensive prediction and assessment system which is mainly focused on outdoor environment composite index WBGT can be established combining with assessment method on wind environment outdoor of predecessors in order to more accurately and humanly predict and assess the wind environment outdoor, bring safe, comfortable and healthy outdoor environment and provide references for the assessment and design of green residential district.

scholarly journals Cockroaches traverse crevices, crawl rapidly in confined spaces, and inspire a soft, legged robot

2016 ◽  
Vol 113 (8) ◽  
pp. E950-E957 ◽  
Author(s):  
Kaushik Jayaram ◽  
Robert J. Full
Keyword(s):  
Body Weight ◽  
High Speed ◽  
Stride Length ◽  
Body Height ◽  
Legged Robot ◽  
Confined Space ◽  
Performance Limits ◽  
Biological Inspiration ◽  
Confined Spaces ◽  
Postural Changes

Jointed exoskeletons permit rapid appendage-driven locomotion but retain the soft-bodied, shape-changing ability to explore confined environments. We challenged cockroaches with horizontal crevices smaller than a quarter of their standing body height. Cockroaches rapidly traversed crevices in 300–800 ms by compressing their body 40–60%. High-speed videography revealed crevice negotiation to be a complex, discontinuous maneuver. After traversing horizontal crevices to enter a vertically confined space, cockroaches crawled at velocities approaching 60 cm⋅s−1, despite body compression and postural changes. Running velocity, stride length, and stride period only decreased at the smallest crevice height (4 mm), whereas slipping and the probability of zigzag paths increased. To explain confined-space running performance limits, we altered ceiling and ground friction. Increased ceiling friction decreased velocity by decreasing stride length and increasing slipping. Increased ground friction resulted in velocity and stride length attaining a maximum at intermediate friction levels. These data support a model of an unexplored mode of locomotion—“body-friction legged crawling” with body drag, friction-dominated leg thrust, but no media flow as in air, water, or sand. To define the limits of body compression in confined spaces, we conducted dynamic compressive cycle tests on living animals. Exoskeletal strength allowed cockroaches to withstand forces 300 times body weight when traversing the smallest crevices and up to nearly 900 times body weight without injury. Cockroach exoskeletons provided biological inspiration for the manufacture of an origami-style, soft, legged robot that can locomote rapidly in both open and confined spaces.

Assessment of Certainty of Ventilation Processes Mathematical Modeling

2015 ◽  
Vol 725-726 ◽  
pp. 1255-1260
Author(s):  
Tamara Daciuk ◽  
Vera Ulyasheva
Keyword(s):  
Mathematical Modeling ◽  
Turbulent Flows ◽  
Turbulence Models ◽  
Field Measurements ◽  
Heat Emission ◽  
Emission Sources ◽  
Wide Range ◽  
Calculation Results ◽  
Definition Of ◽  
Semiempirical Models

Numerical experiment has been successfully used during recent 10-15 years to solve a wide range of thermal and hydrogasodynamic tasks. Application of mathematical modeling used to design the ventilation systems for production premises characterized by heat emission may be considered to be an effective method to obtain reasonable solutions. Results of calculation performed with numerical solution of ventilation tasks depend on turbulence model selection. Currently a large number of different turbulence models used to calculate turbulent flows are known. Testing and definition of applicability limits for semiempirical models of turbulence should be considered to be a preliminary stage of calculation. This article presents results of test calculations pertaining to thermal air process modeling in premises characterized by presence of heat emission sources performed with employment of different models of turbulence. Besides, analysis of calculation results and comparison with field measurements data are presented.

Sign in / Sign up

Export Citation Format

Share Document