scholarly journals Numerical Analysis for Smoke Spread in an Aircraft Hangar

2019 ◽  
Vol 111 ◽  
pp. 01090
Author(s):  
Essam E. Khalil ◽  
Hatem Kayed Haridy ◽  
Eslam Said Abdelghany Ahmed ◽  
Ahmed Ashraf Mohamed
Keyword(s):  
Numerical Analysis ◽  
Ventilation System ◽  
Spread Rate ◽  
Air Velocity ◽  
Supply Rate ◽  
Traditional System ◽  
Smoke Spread ◽  
Dynamic Simulator ◽  
Fire Dynamic Simulator ◽  
Evacuation Plan

Smoke is one of the most dangerous factors in aircraft hangar in case of fire. As it causes reduce in visibility and deaths due to high temperature or toxicity also prevents applying evacuation plan for workers. This study present numerical analysis for improving traditional system of ventilation system to manage smoke produced due to push-back vehicle on fire at hangar. By studying effect of changing extraction and supply rates, the number of extraction and supply fans, and the arrangement of extraction and supply fans on the visibility, temperature and air velocity at human level to insure not to exceed limits stated by NFPA 130[1] to apply evacuation plan for workers. The study is performed using Fire dynamic simulator to simulate 16 case studies in the hangar of airports in Brandenburg. The hangar has the outer dimensions of 83.40 m width and 77.60 m depth and thus an inner area of approx. 6,472 m2. The hangar has a medium interior height of approximately 18.20 m. The results show that using extraction fans with rate (ACH) double the supply rate for the traditional ventilation system gives very good results in controlling the smoke. As well as, decreasing the number of supply fans will make the smoke spread rate inside the hangar lower, which helps to control the smoke spread of fire in less time.

Numerical Analysis on the Effect of Thermal Insulation of Closure on Fire Smoke Spread Rate in Building's Corridor

2014 ◽  
Vol 513-517 ◽  
pp. 2635-2638
Author(s):  
Xuan Wei Peng
Keyword(s):  
Numerical Analysis ◽  
Thermal Insulation ◽  
Air Temperature ◽  
Spread Rate ◽  
Smoke Flow ◽  
External Insulation ◽  
Flow Prediction ◽  
Smoke Spread ◽  
Fire Smoke ◽  
Fire Ignition

The corridor is an important way of evacuation and rescue in building fire. The fire smoke flow prediction software developed successfully was applied to simulate a building with a 28.8 meters long corridor to investigate the effect of the different thermal insulation on fire smoke spread rate. Two representative thermal insulation, external insulation and internal insulation were compared. In 3600s fire time, air temperature in the corridor of external insulation is much lower than that of internal insulation. The air temperature gap gets narrowed between the two insulation methods in the corridor with the prolongation of fire time. Temperature difference increases as the distance increase from the fire ignition place. The corridor gets unsafe of internal insulation in 7 minute since fire ignition, while about half the length of the corridor stay secure of external insulation in 10 minutes since fire ignition. That implies more available safe egress time can be gained with external insulation than internal insulation. Smoke spread rate was numerically compared based on the air temperature variation. Smoke spread rate of internal insulation is much higher than that of external insulation and the corresponding ratio is 1.732:1.

scholarly journals MODELLING OF FIRE IN AN OPEN CAR PARK

2016 ◽  
Author(s):  
Timea Márton ◽  
Anne Dederichs ◽  
Luisa Giuliani
Keyword(s):  
Mechanical Properties ◽  
High Temperatures ◽  
Fire Spread ◽  
Current Paper ◽  
Spread Rate ◽  
Dynamic Simulator ◽  
Car Park ◽  
Fire Dynamic Simulator ◽  
Fire Accidents

Steel car parks exhibit high vulnerability to fire, as a consequence of the degradation of the steel mechanical properties at high temperatures and of the combustible type and amount. Real fire accidents in open car parks demonstrated a much faster and extended fire spread than predictions, assuming that a fire spread rate of 12 min and consider at most 3-4 vehicles on fire at the same time. Fire Dynamic Simulator (FDS) is applied in this current paper to study fire spread between cars. The outcomes of the investigations show that the fire spread is strongly influenced by the geometrical layout and that the distance between cars plays a determinant role on the fire spread rate and ignition of adjacent cars. In particular it was found that the fire spread can be faster than 12 minutes in the case of the cars parked 40 and 60 cm from each other.

Effects of Exit Vent Location on Fire Room Conditions During PPV

2008 ◽  
Author(s):  
Colin M. Beal ◽  
Ofodike A. Ezekoye
Keyword(s):  
Positive Pressure ◽  
Computational Simulations ◽  
Cold Flow ◽  
Flow Simulations ◽  
Advantages And Disadvantages ◽  
Experimental Compartment ◽  
Dynamic Simulator ◽  
Fire Dynamic Simulator ◽  
Hot Products ◽  
Vent Location

Positive Pressure Ventilation (PPV) is a widely used fire fighting tactic in which a fan is used to push hot products of fire out of a burning structure. There is a recent body of research that has been conducted regarding the advantages and disadvantages of PPV. Studies of PPV most commonly use full scale experimental fires and/or computational simulations to evaluate its effectiveness. This paper presents computational simulations that have been conducted using Fire Dynamic Simulator (FDS) version 5 to evaluate the effects of exit vent location on resulting fire room conditions during the application of PPV to a ventilation constrained fire. The simulations use a simple one room structure with an adjacent hallway. We are simulating this geometry because we are in the process of designing and constructing a similar experimental compartment. Cold flow simulations are first conducted to understand how much the presence of the fire heat release affects the flow patterns. Then, two simulations which employ PPV with different exit vent locations are compared. The differences between the two simulations are detailed and a physical explanation for the differences is presented.

scholarly journals ANALYSIS OF HEAT RELEASE RATE IN ENGINE ROOM FIRES OF 300 GT FERRY RO-RO PASSENGER BY USING WATER MIST SYSTEM AND CO2 SYSTEM

2021 ◽  
Vol 15 (2) ◽  
Author(s):  
Wira Setiawan ◽  
Distyan Kotanjungan
Keyword(s):  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Fire Suppression ◽  
Water Mist ◽  
Engine Room ◽  
Passenger Ships ◽  
Dynamic Simulator ◽  
Fire Dynamic Simulator ◽  
Suppression System

Based on statistical data in recent years, there are still quite a number of ship accidents due to fires, including on passenger ships. The water mist system is a fire suppression system that allows it to be used in the engine room with the advantage that it can keep the heat production rate low during the extinguishing process and can be operated earlier than the CO2 system. The research is conducted by using fire dynamic simulator in the engine room of a 300 GT ferry ro-ro passenger to compare the heat release rate of fire without an extinguishing system, an existing CO2 system, and a water mist system. The result shows that the CO2 fire suppression system reduces the heat release rate more rapidly to the decay phase at 375 seconds while the water mist takes more than 900 seconds. However, the fully developed phase of the water mist suppression system occurs more quickly than CO2 because the sprinklers are activated shortly after a fire occurs. Unlike water mist, the CO2 system is activated at 60 seconds so that the pre-combustion, growth, flashover, and fully developed phases are at the same HRR and time as the natural one.

Evaluation of Indoor Climate in Big Lecture Hall

2019 ◽  
Vol 887 ◽  
pp. 475-483
Author(s):  
Mária Budiaková
Keyword(s):  
Thermal Comfort ◽  
Ventilation System ◽  
Winter Season ◽  
Point Of View ◽  
Lecture Hall ◽  
Experimental Measurements ◽  
Optimal Parameters ◽  
Indoor Climate ◽  
Air Velocity ◽  
Operation System

The paper is oriented on the evaluation of the indoor climate in the big lecture hall. Providing the optimal parameters of the thermal comfort and the CO2 concentration is immensely important for the students in the interiors of a university. Meeting these parameters is inevitable not only from physiological point of view but also for achieving the desirable students' performance. The high CO2 concentration is related to incorrect and insufficient ventilation in the lecture hall and causes distractibility and feeling of tiredness of students. Experimental measurements were carried out in the winter season in 2016 in the big lecture hall in order to evaluate the thermal comfort and the CO2 concentration. The device Testo 480 was used for the measurements. Obtained values of air temperature, air relative humidity, air velocity, CO2 concentration are presented in the charts. Mechanical ventilation system and operation system of the big university lecture hall were evaluated on the basis of the parameters of the thermal comfort and on the basis of the CO2 concentration. Based on the findings, design recommendations for new big university lecture halls are derived. Furthermore, there are presented recommendations how to operate the existing big university lecture halls.

scholarly journals Optimizing air velocity for the underfloor forced ventilation to protect a refrigerated warehouse from frost heaving

2018 ◽  
Vol 38 (3) ◽  
pp. 321-327
Author(s):  
Jingfu Jia ◽  
Manjin Hao ◽  
Jianhua Zhao
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Natural Ventilation ◽  
Ventilation System ◽  
Three Dimensional ◽  
Temperature Fields ◽  
Frost Heave ◽  
Forced Ventilation ◽  
Air Velocity ◽  
Set Up

Forced or natural ventilation is the most common measure of frost heave protection for refrigerated warehouse floor. To optimize air velocity for the underfloor forced ventilation system of refrigerated warehouse, a steady state three-dimensional mathematical model of heat transfer is set up in this paper. The temperature fields of this system are simulated and calculated by CFD software PHOENICS under different air velocity, 1.5m/s, 2.5m/s or 3.5m/s. The results show that the optimized air velocity is 1.5m/s when the tube spacing is 1.5m.

scholarly journals Numerical simulations for the optimisation of ventilation system designed for wine cellars

2019 ◽  
Vol 50 (4) ◽  
pp. 180-190 ◽  
Author(s):  
Enrica Santolini ◽  
Alberto Barbaresi ◽  
Daniele Torreggiani ◽  
Patrizia Tassinari
Keyword(s):  
Natural Ventilation ◽  
Ventilation System ◽  
Climatic Conditions ◽  
Mold Growth ◽  
Critical Factors ◽  
Air Velocity ◽  
Wine Production ◽  
First Case ◽  
Dynamics Modelling ◽  
Optimal Configurations

The wine-ageing process is one of the most important phases of the wine production and it can be considerably affected by the micro-climatic conditions inside the ageing rooms. Underground wine cellars in small-medium wineries are designed with natural ventilation systems, able to maintain optimal indoor condition. However, critical factors emerge, such as mold growth or wine evapo-transpiration, where ventilation proved to be poorly designed, insufficient in the first case or excessive in the second one. The zones around the wooden barrels proved to be the most sensitive and problematic. These areas are the most investigated in terms of temperature and humidity values but surprisingly not in terms of air velocity. In this paper, a ventilation system has been designed and optimised to support the lack of ventilation, by means of computational fluid dynamics modelling. Eight configurations have been performed and analysed, identifying the best two according to the air velocity range. Specific parameters have been defined to appreciate the application limits of each configuration. These parameters can be used as reference for system design in similar studies and applications and can help scholars and professionals to identify the optimal configurations for the implementation and proper placement of the system inside a cellar.

Underground Research Laboratories in Japan: What Are the Important Factors for Facilities Design?

2003 ◽  
Author(s):  
T. Sato ◽  
S. Mikake ◽  
M. Sakamaki ◽  
K. Aoki ◽  
S. Yamasaki ◽  
...  
Keyword(s):  
Numerical Analysis ◽  
Sedimentary Rock ◽  
Mechanical Stability ◽  
Ventilation System ◽  
Sedimentary Rocks ◽  
Crystalline Rock ◽  
Ventilation Network ◽  
Main Stage ◽  
Middle Stage ◽  
Ventilation Shaft

This paper describes the current status of two Japanese off-site Underground Research Laboratories (URLs) Projects, one for crystalline rock and the other for sedimentary rock. This paper is focused on mechanical stability and ventilation, important factors relevant to the design and construction of deep underground facilities. High-pressure inflow, another important factor, will be included in the URL project for crystalline rock. The site of the URL project for crystalline rock is located in Mizunami, Gifu, in the central part of the main island of Japan. The regional geology consists of the Tertiary and Quaternary sedimentary rocks overlying Cretaceous granitic basement. Surface-based investigations, including geological mapping, a seismic refraction survey and shallow borehole investigations, and site preparation at the MIU (Mizunami Underground Research Laboratory) Project site have started in 2002. Numerical analysis is carried out to understand mechanical stability around the openings. The ventilation system design is based on numerical analysis using a ventilation network model. Grouting against the high-pressure inflow is planned. Conceptual design for the MIU at present is as follows: • Two 1,000 m shafts, a Main Shaft (6.5m φ) and a Ventilation shaft (4.5m φ); • Two experimental levels, the Main Stage at 1,000 m and the Middle Stage, at 500 m depths. The site of the URL project for sedimentary rock is located in Horonobe, Hokkaido, north of the main island of Japan. The geology consists of Tertiary sedimentary rocks. Surface-based investigation phase started in 2001. Numerical analysis is carried out to understand mechanical stability of the openings, and to design support. The numerical analysis using ventilation network model is carried out to design the ventilation system and disaster prevention method. Conceptual design for the Hnb-URL at present is as follows: • Two 500 m shafts and a Ventilation shaft; • Two experimental levels, the Main Stage at 500 m and the Middle Stage at 250 m depths.

Large Outdoor Fire Model Analysis

2003 ◽  
Author(s):  
Peter Vidmar ◽  
Stojan Petelin
Keyword(s):  
Fluid Dynamic ◽  
Fire Behavior ◽  
Combustion Products ◽  
Validity Of Results ◽  
Quality Of Results ◽  
Fire Model ◽  
Dynamic Simulator ◽  
Fire Dynamic Simulator ◽  
The Mathematical Model

The idea behind the article is how to define fire behavior. The work is based on an analytical study of fire origin, its development and spread. Mathematical fire model called FDS (Fire Dynamic Simulator) in used in a presented work. CFD (Computational Fluid Dynamic) model using LES (Large Eddie Simulation) is used to calculate fire development and spread of combustion products in the environment. The fire source is located in the vicinity of the hazardous plant, power, chemical etc. The article present the brief background of the FDS computer program and the initial and boundary conditions used in the mathematical model. Results discuss output data and check the validity of results. The work also presents some corrections of physical model used, which influence the quality of results.

Study of Fire Smoke Flow of Tunnel at Different Longitudinal Ventilation

2012 ◽  
Vol 226-228 ◽  
pp. 1472-1475
Author(s):  
Pei Pei Yang ◽  
Xiao Lu Shi ◽  
Bi Ming Shi
Keyword(s):  
Flow Resistance ◽  
Reverse Flow ◽  
Ventilation System ◽  
Gas Temperature ◽  
Smoke Control ◽  
Smoke Flow ◽  
Longitudinal Ventilation ◽  
Smoke Spread ◽  
Fire Smoke ◽  
Safety Evacuation

Once the tunnel fires happened, it will cause a major accident. And the smoke control of the runnel is important to fire prevention. A numerical simulation of the fire smoke flow in the tunnel model is presented by using FDS. The influence of different longitudinal ventilation on fire smoke flow of tunnel is obtained. And providing theory basis for tunnel ventilation system design, smoke spread control and safety evacuation. The results shown that in order to avoid reverse-flow and extend the time of smoke at the top of tunnel, the longitudinal speed should be controlled in 3.4 m/s; because of the role of longitudinal ventilation, smoke flow resistance and longitudinal ventilation generated by the effect of smoke flow resistance make the gas temperature first rise and then down.

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