scholarly journals Full-scale and reduced-scale tests on smoke movement in case of car park fire

2013 ◽  
Vol 57 ◽  
pp. 35-43 ◽  
Author(s):  
István Horváth ◽  
Jeroen van Beeck ◽  
Bart Merci
Keyword(s):  
Full Scale ◽  
Smoke Movement ◽  
Car Park ◽  
Reduced Scale

PPV Effect on Smoke Movement Through a Shaft in High-Rise Fires: Experiments and CFD Simulation

2019 ◽  
Author(s):  
Xiaoman Ye ◽  
Ofodike A. Ezekoye ◽  
Qize He
Keyword(s):  
Positive Pressure Ventilation ◽  
Cfd Simulation ◽  
Positive Pressure ◽  
Gas Temperature ◽  
Air Flow Rate ◽  
Smoke Control ◽  
Smoke Movement ◽  
Cfd Simulations ◽  
High Rise ◽  
Reduced Scale

Abstract While Positive Pressure Ventilation (PPV) has proven to be effective in high-rise fire-fighting, its effect on smoke movement through a stairwell shafts in high-rise fires is still inconclusive. Towards better understanding of the effects of PPV for smoke transport in high-rise type structures, a 1/4 reduced-scale 7-floor building with dimensions of 1.0 m × 0.5 m × 4.2 m consisting of a vertical shaft and several rooms over a number of floors has been designed and tested. Both experiments and CFD simulations for this model were conducted. It was found that there are several potential PPV tactics that could be useful in high-rise smoke control in fires. In the cases examined, PPV was considered to be applied from outside the building through vents in external rooms of the building. When a PPV fan is applied above the floor containing the fire layer, the pressure induced by the PPV flow should be larger than the pressure difference caused by the stack effect induced by the hot fire product gases. Insufficient PPV flow rates is shown to lead to accumulation of smoke and further increase in the gas temperature within the shaft due to the blocking effect. A better option is applying PPV below the fire floor. With the same pressurization air flow rate, applying PPV from below the fire floor is more effective than applying it from the top of building. In this situation, PPV not only prevents accumulation of the smoke in the shaft, but also prevents smoke from entering the shaft. The results of this study can guide the development of firefighter ventilation tactics for smoke control in high-rise fires.

scholarly journals On the extrapolation of CFD results for smoke and heat control in reduced-scale set-ups to full scale: Atrium configuration

2013 ◽  
Vol 59 ◽  
pp. 160-165 ◽  
Author(s):  
Nele Tilley ◽  
Pieter Rauwoens ◽  
Dieter Fauconnier ◽  
Bart Merci
Keyword(s):  
Full Scale ◽  
Heat Control ◽  
Reduced Scale

scholarly journals Smoke Obscuration Measurements in Reduced-Scale Fire Modelling Based on Froude Number Similarity

Sensors ◽  
2019 ◽  
Vol 19 (16) ◽  
pp. 3628 ◽  
Author(s):  
Wojciech Węgrzyński ◽  
Piotr Antosiewicz ◽  
Tomasz Burdzy ◽  
Mateusz Zimny ◽  
Adam Krasuski
Keyword(s):  
Froude Number ◽  
Similarity Criterion ◽  
Optical Filters ◽  
Optical Path Length ◽  
Full Scale ◽  
Fire Modelling ◽  
Smoke Layer ◽  
New Type ◽  
Geometrical Scale ◽  
Reduced Scale

A common method for investigating various fire- and smoke-related phenoma is a reduced-scale fire modelling that uses the conservation concept of Froude number as its primary similarity criterion. Smoke obscuration measurements were not commonly used in this approach. In this paper, we propose a new type of optical densitometer that allows for smoke obscuration density measurements on a reduced-scale. This device uses a set of mirrors to increase the optical path length, so that the device may follow the geometrical scale of the model, but that still measures smoke obscuration as if it were in full scale. The principle of operation is based on the Bougher-Lambert-Beer law, with modifications related to the Froude number-based scaling principles, to streamline the measurements. The proposed low-budget (< $1000) device was built, calibrated with a set of the reference optical filters, and used in a series of full- (1:1) and reduced-scale (1:4) experiments with n-Heptane fires in a small compartment. The main limitation of this study is the assumption that there is similar soot production in full- and reduced-scale fires, which may not be true for many Froude-number scaling applications. Therefore, it must be investigated in a case-by-case basis. In our case, the results are promising. The measured obscuration in the reduced-scale had a 10% error versus averaged measurements in full-scale measurements. Moreover, there were well represented transient changes of the smoke layer optical density during the combustion and after the smoke layer settled.

SCALING METHODOLOGY FOR BUCKLING OF COMPOSITE CONICAL SHELLS IN AXIAL COMPRESSIONConical shells are commonly used as structural components for launch vehicles. The axial compression experienced during launch is one of the sizing load cases, because it can lead to loss of structural stability. Because experimentally testing these full-scale structures is cumbersome and expensive, it is expedient to understand how reduced-scale shells can be designed such that their buckling behavior is representative of the full-scale shell behavior. An analytical, sequential scaling methodology is developed based on the nondimensional governing equations for composite conical shells with a symmetric, balanced layup and negligible flexural anisotropy. Linear and nonlinear finite element analyses characterizing the buckling behavior of the different size shells yielded comparable results in terms of buckling load, meridional displacement, and buckling mode. The inclusion of geometric imperfections affects the prediction accuracy, but not to the extent that the methodology is no longer valid.

2021 ◽  
Author(s):  
KAAT PAREYNS ◽  
CHIARA BISAGNI ◽  
MICHELLE T. RUDD ◽  
MARC R. SCHULTZ
Keyword(s):  
Full Scale ◽  
Launch Vehicles ◽  
Structural Components ◽  
Governing Equations ◽  
Buckling Mode ◽  
Conical Shells ◽  
Buckling Behavior ◽  
Meridional Displacement ◽  
Scale Structures ◽  
Reduced Scale

Conical shells are commonly used as structural components for launch vehicles. The axial compression experienced during launch is one of the sizing load cases, because it can lead to loss of structural stability. Because experimentally testing these full-scale structures is cumbersome and expensive, it is expedient to understand how reduced-scale shells can be designed such that their buckling behavior is representative of the full-scale shell behavior. An analytical, sequential scaling methodology is developed based on the nondimensional governing equations for composite conical shells with a symmetric, balanced layup and negligible flexural anisotropy. Linear and nonlinear finite element analyses characterizing the buckling behavior of the different size shells yielded comparable results in terms of buckling load, meridional displacement, and buckling mode. The inclusion of geometric imperfections affects the prediction accuracy, but not to the extent that the methodology is no longer valid.

scholarly journals Experimental Investigation of the Flow on a Simple Frigate Shape (SFS)

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Rafael Bardera Mora
Keyword(s):  
Experimental Data ◽  
Experimental Investigation ◽  
Wind Tunnel ◽  
Full Scale ◽  
Typical Case ◽  
Ship Model ◽  
Computational Aerodynamics ◽  
A Priority ◽  
Reduced Scale ◽  
Comparison With Experimental Data

Helicopters operations on board ships require special procedures introducing additional limitations known as ship helicopter operational limitations (SHOLs) which are a priority for all navies. This paper presents the main results obtained from the experimental investigation of a simple frigate shape (SFS) which is a typical case of study in experimental and computational aerodynamics. The results obtained in this investigation are used to make an assessment of the flow predicted by the SFS geometry in comparison with experimental data obtained testing a ship model (reduced scale) in the wind tunnel and on board (full scale) measurements performed on a real frigate type ship geometry.

scholarly journals Smoke control in case of fire in a large car park: CFD simulations of full-scale configurations

2013 ◽  
Vol 57 ◽  
pp. 22-34 ◽  
Author(s):  
X. Deckers ◽  
S. Haga ◽  
N. Tilley ◽  
B. Merci
Keyword(s):  
Full Scale ◽  
Smoke Control ◽  
Cfd Simulations ◽  
Car Park

Numerical simulations on fire spread and smoke movement in an underground car park

2007 ◽  
Vol 42 (10) ◽  
pp. 3466-3475 ◽  
Author(s):  
X.G. Zhang ◽  
Y.C. Guo ◽  
C.K. Chan ◽  
W.Y. Lin
Keyword(s):  
Numerical Simulations ◽  
Fire Spread ◽  
Smoke Movement ◽  
Car Park

Initial Buoyancy Reduction in Exhausting Smoke With Solar Chimney Design

2009 ◽  
Vol 132 (1) ◽  
Author(s):  
C. L. Chow ◽  
W. K. Chow
Keyword(s):  
Solar Radiation ◽  
Wall Temperature ◽  
Early Stage ◽  
Exhaust System ◽  
Equation Of Motion ◽  
Full Scale ◽  
Smoke Movement ◽  
Fire Response ◽  
Solar Chimney ◽  
Set Up

A possible problem in using solar chimney as a natural smoke exhaust system will be identified in this paper. Smoke generated in a fire might not be removed effectively if the glazing walls are heated up due to exposure to solar radiation. It is because the buoyancy of the smoke is reduced initially in the solar chimney. This phenomenon of reducing buoyancy will be discussed. A simple equation of motion on smoke movement was set up. Some of the results of full-scale burning experiments carried out earlier for assessing the fire response of a glass façade system were applied to support the argument. Experiments indicated that smoke would take a longer time to move up when the glazing wall temperature is higher. A better smoke exhaust design accounting the reduction in buoyancy at this early stage of a fire should be worked out.

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