scholarly journals Numerical simulation on the influence of low air pressure upon smoke spread and fire alarm process

2021 ◽  
Vol 26 ◽  
pp. 101004
Author(s):  
Lei Xu ◽  
Wei Zheng
Keyword(s):  
Numerical Simulation ◽  
Air Pressure ◽  
Fire Alarm ◽  
Smoke Spread

Investigation into the Characteristic of Air Pressure Field in the Melt Blowing with Dual Slots via Numerical Simulation

2012 ◽  
Vol 538-541 ◽  
pp. 804-809 ◽  
Author(s):  
San Fa Xin ◽  
Xin Hou Wang
Keyword(s):  
Numerical Simulation ◽  
Pressure Difference ◽  
Research Method ◽  
Pressure Field ◽  
Three Dimensional ◽  
Air Pressure ◽  
Melt Blowing ◽  
Main Research

The characteristic of air pressure field in melt blowing with dual slots was studied. The main research method was the numerical simulation of three dimensional. The results show that the air pressure field is symmetric. There exist two sections: the pressure difference section and the zero-pressure difference section along the whole centerline. In the pressure difference section, there also exist three sub-sections.

scholarly journals Research on factors affecting bus fire based on numerical simulation

2021 ◽  
Vol 303 ◽  
pp. 01042
Author(s):  
Min Xu ◽  
Pengyi Bu ◽  
Lin Xin ◽  
Chao Li ◽  
Limin Han ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Heating Rate ◽  
Rapid Development ◽  
Factors Affecting ◽  
Smoke Spread ◽  
Fire Smoke ◽  
Co Concentration ◽  
In Fire

With the rapid development of economy, the number of buses and bus fire increases. This paper takes bus as the research object and uses software FDS to explore the fire smoke spread under different fire power conditions. The results show that: with the increase in fire power, the smoke in the compartment rapidly accumulates, and the heating rate is also accelerated. The visibility decreases with the diffusion of smoke in the compartment. The CO concentration increases with time. The greater the fire power, the higher the temperature which will eventually stabilize. Only the concentration of smoke near the entrance will be slightly reduced. This is also conducive to the escape of people inside the car.

scholarly journals Research on Distribution Properties of Coating Film Thickness from Air Spraying Gun-Based on Numerical Simulation

Coatings ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 721 ◽  
Author(s):  
Xiaopeng Xie ◽  
Yinan Wang
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Film Thickness ◽  
Coating Thickness ◽  
Thickness Distribution ◽  
Air Pressure ◽  
Reasonable Assumption ◽  
Coating Film ◽  
Discrete Phase Model ◽  
Spraying Process

This work aims to study the influence of the spraying parameters on the spray flow field and coating thickness distribution during the air spraying process. The shaping air pressure and the target geometry have an important influence on the distribution of coating film thickness. This paper begins with a 3-D physical model of an air spray gun, in which unstructured grids were generated for control domain. A grid independency study was also carried out to determine the optimal number of cells for the simulations. Then the Euler–Lagrange method was used to describe the two-phase spray flow by establishing a paint deposition model. The numerical simulation based on the discrete phase model (DPM) and TAB model has been carried out. A reasonable assumption was proposed based on the analysis of the spraying process, so that the droplets were injected into the airflow at the position of the paint hole. The influence of the shaping air pressure on the air flow field and the coating thickness distribution was analyzed by changing the shaping air pressure. From the numerical simulation results, it can be concluded that the smaller the shaping air pressure, the more concentrated the coating. With increasing the shaping air pressure, the length of the coating film along z-axis gradually increases, the width along x-axis gradually decreases, and the spray area gradually increases. The paper ends with a numerical simulation and experimental study on planar vertical spraying, planar tilted spraying, and cylinder spraying. Comparisons and experiment results verify the validity and practicability of the model built in this paper.

Full-Scale Experimental and Numerical Simulation of Fire in a High-Rise Residential Building

2012 ◽  
Vol 594-597 ◽  
pp. 2251-2256
Author(s):  
Jun Tao Yang ◽  
Yun Yang ◽  
Jing Liang
Keyword(s):  
Numerical Simulation ◽  
Residential Building ◽  
Full Scale ◽  
Fire Dynamics ◽  
High Rise ◽  
Fire Dynamics Simulator ◽  
Smoke Spread

Fires in high-rise residential building were studied experimentally by using an actual building with similar inner structure. The temperatures in the building interior corridors, elevators and staircases exit were measured. At the same time the fires in this construction were simulated by using FDS (Fire Dynamics Simulator) software, the variance trends of the temperatures in different positions within high-rise residential building were studied and compared with the experiment results, and the results of this simulation are proved to be valid. The results can be used to support the study of effectively controlling of the smoke spread and evacuation in high-rise residential building.

Simulation Study on the Wind Pressure of Village Flat Roof with Parapet Based on Different Wind Angles

2014 ◽  
Vol 638-640 ◽  
pp. 228-232 ◽  
Author(s):  
Jun Liu ◽  
Yuan Quan Yang ◽  
Yan Lei Sun ◽  
Bin He
Keyword(s):  
Numerical Simulation ◽  
Wind Tunnel ◽  
Pressure Fluctuation ◽  
Field Measurement ◽  
Pressure Coefficient ◽  
Air Pressure ◽  
Wind Pressure ◽  
Simulation Technology ◽  
Wind Tunnel Tests ◽  
Flat Roof

The main research methods to predict and research wind loads on buildings at home and abroad include wind tunnel tests, field measurement and numerical simulation. However, the wind tunnel tests and field measurement require big funds, long cycle and complicated measurement. Moreover, numerical simulation technology is quite mature. In this paper, based on fluid dynamics software CFD and criteria Reynolds k-ε turbulence model, wind field of the village flat roof with parapet is studied using the numerical simulation technology. Furthermore, the wind pressure data in different wind angles are processed and analyzed. The results show that wind angle has a significant impact on the wind pressure and its distribution. When the wind angle is 0 °, the air pressure-fluctuation in each node of the roof is small, and the pressure coefficient is steady between -1.50 and -2.00. When the wind angle is 45 °, the air pressure fluctuation in each node of the roof is large, and the pressure coefficient fluctuates between -0.8 and -3.0. When the wind angle is 90 °, the wind pressure-fluctuation in each node of the roof is equal to the fluctuation between 0 ° and 45 °wind direction angle, and the wind pressure coefficient fluctuates between -0.7 and -1.7. When incoming flow is along the asymmetric axis, the wind pressure-fluctuation is large, and the wind pressure is greater than that in the large negative pressure zone which is along the symmetry axis, which can bring serious damage on the roof.

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