Some Experimental Results on Internal Fire Whirls in a Vertical Shaft

2013 ◽  
Author(s):  
Y. Gao ◽  
G. W. Zou ◽  
S. S. Li ◽  
W. K. Chow
Keyword(s):  
Full Scale ◽  
Pool Fire ◽  
Experimental Results ◽  
Vertical Shaft ◽  
Remote Site ◽  
Scale Modeling ◽  
Key Factor ◽  
Fire Whirl ◽  
Real Scale

Earlier studies on burning a pool fire in a vertical shaft model indicated that appropriate sidewall ventilation provision is a key factor for the onset of an internal fire whirl. Experiments on burning a pool fire inside a real-scale shaft model of 9 m tall were performed to further investigate the swirling motion. The full-scale modeling burning tests were carried out at a remote site in China. Four different ventilation openings were arranged. Results of onsetting of internal fire whirls for the four tests will be reported.

Internal Fire Whirls Induced by Pool Fire in a Vertical Shaft

2011 ◽  
Author(s):  
Yan Huo ◽  
W. K. Chow ◽  
Ye Gao
Keyword(s):  
Flow Field ◽  
Numerical Simulations ◽  
Air Flow ◽  
Pool Fire ◽  
Vertical Shaft ◽  
Pool Fires ◽  
Key Factor ◽  
Fire Whirl ◽  
Gap Width

Internal fire whirls induced by a pool fire in a square vertical shaft were studied by experiments and numerical simulations. The burning behaviour of two pool fires in the vertical shaft and in open air was compared. The gap width of the rig is a key factor in onsetting fire whirls. Air flow field in the vertical square shaft of different gap widths were studied experimentally with nine tests. A fire whirl would not be onsetted when the gap is too narrow nor too wide. Whirling flame is not clearly observed near to the bottom of the vertical shaft when the gap width was small.

scholarly journals Observation on a fire whirl in a vertical shaft using high-speed camera and associated correlation derived

2019 ◽  
pp. 266-266
Author(s):  
Hing Hung ◽  
Shousuo Han ◽  
Wan Chow ◽  
Cheuk Chow
Keyword(s):  
Burning Rate ◽  
High Speed ◽  
Tall Buildings ◽  
Burning Surface ◽  
Air Entrainment ◽  
Pool Fire ◽  
Flame Height ◽  
Vertical Shaft ◽  
High Speed Camera ◽  
Fire Whirl

The fire whirl generated by burning a pool fire in a vertical shaft with a single corner gap of appropriate width was studied using a high-speed camera. A 7-cm diameter pool propanol fire with heat release rate 1.6 kW in free space was burnt inside a 145-cm tall vertical shaft model with gap widths lying between 2 cm and 16 cm. The flame height was between 0.25 m and 0.85 m for different gap widths. Photographs taken using a high-speed camera at critical times of swirling motion development were used to compare with those taken using a normal camera. From the experimental observations on flame swirling by a high-speed camera, stages for generating the fire whirl were identified much more accurately. Two flame vortex tubes moving over the horizontal burning surface of the liquid pool were observed. Based on these observations a set of more detailed schematic diagrams on the swirling motion was constructed. From the observed flame heights under different gap widths and using three assumptions on the variation of air entrainment velocity with height, an empirical expression relating the burning rate with flame height and the corner gap width was derived from the observation with high-speed camera. The correlation expression of the burning rate of the pool fire obtained would be useful in fire safety design in vertical shafts of tall buildings.

A study of correlation between flame height and gap width of an internal fire whirl in a vertical shaft with a single corner gap

2017 ◽  
Vol 28 (1) ◽  
pp. 34-45 ◽  
Author(s):  
G. W. Zou ◽  
H. Y. Hung ◽  
W. K. Chow
Keyword(s):  
Experimental Data ◽  
Fire Safety ◽  
Air Entrainment ◽  
Pool Fire ◽  
Flame Height ◽  
Vertical Shaft ◽  
Entrainment Velocity ◽  
Fire Safety Design ◽  
Fire Whirl ◽  
Gap Width

An internal fire whirl can be generated by a pool fire burning in a vertical shaft with a single corner gap of appropriate width. In an internal fire whirl, the flame height is an important characteristic in terms of fire safety. In this paper, a correlation expression of flame height with the width of a single corner gap was studied using reported experimental data in a 9-m tall vertical shaft model. A pool of gasoline fuel was burnt inside the shaft model to study the characteristics of flame swirling. An internal fire whirl was generated for gap widths lying between 0.11 m and 0.66 m, when the pool fire was 0.46 m diameter. The flame height was between 2.5 m and 3.2 m. From the experimental observations on flame swirling for different gap widths, coupled with three assumptions on variation of air entrainment velocity with height, an expression relating the flame height and the corner gap width was derived for the internal fire whirl using a set of compiled experimental data. The correlation expression obtained would be useful for fire safety design in vertical shafts.

Modal Strain Energy Based Damage Detection Applied to a Full Scale Composite Helicopter Blade

2013 ◽  
Vol 569-570 ◽  
pp. 457-464 ◽  
Author(s):  
Fabio Luis Marques dos Santos ◽  
Bart Peeters ◽  
Herman van der Auweraer ◽  
Luiz Carlos Sandoval Góes
Keyword(s):  
Structural Health Monitoring ◽  
Damage Detection ◽  
Health Monitoring ◽  
Rotor Blade ◽  
Strain Energy ◽  
Full Scale ◽  
Experimental Results ◽  
Main Rotor ◽  
Helicopter Blade ◽  
Main Rotor Blade

The use of composites in the aircraft industry has generated a great need for structural health monitoring and damage detection systems, to allow for safer use of complex materials. Such is the case with helicopter blades - these components nowadays are mostly composed of carbon fiber or glass fiber reinforced plastics laminates, epoxy and honeycomb filled core structures. The use of composite materials on the main rotor blade also allows for more complex and efficient shapes to be designed, but at the same time, their use requires an additional effort when it comes to structural monitoring, since damage can occur and go unnoticed. This work presents experimental results for structural health monitoring method based on strain energy. The test subject is a full-scale composite helicopter main rotor blade, which is a highly flexible, slender beam that can display unusual dynamic behavior with orthotropic behavior. This damage detection method is based on the modal strain properties, and a damage detection index is used to identify and quantify damage. A test setup was built to carry out an experimental modal analysis on the main rotor blade. For that purpose, a total of 55 uniaxial accelerometers were used on the helicopter blade to measure the displacement modes of the structure. To compute the strain modes from the displacement modes, central differences approximation is used. Damage is introduced on the blade by attaching a small mass to two different locations. Experimental results show the possibility of locating damage in this case.

Kalman Filtering for Seam Tracking in Master-Slave Robot Remote Welding System

2011 ◽  
Vol 314-316 ◽  
pp. 1005-1008
Author(s):  
Hong Tang Chen ◽  
Hai Chao Li ◽  
Hong Ming Gao ◽  
Lin Wu
Keyword(s):  
Kalman Filtering ◽  
Seam Tracking ◽  
Experimental Results ◽  
Welding Quality ◽  
Welding Seam ◽  
Tracking Process ◽  
Key Factor ◽  
Remote Welding ◽  
Welding System

Welding seam tracking precision is a key factor influencing welding quality for master-slave robot remote welding system. However, it does not satisfy the welding requirement due to significant noises. To eliminate the influence of noises upon the seam tracking precision and improve the seam tracking precision, a master-slave robot remote welding system was built and Kalman filtering (KF) was applied to the seam tracking process. The experimental results show that the KF eliminated the influence of noises upon the seam tracking precision and improved the seam tracking precision.

Numerical Investigation for Performance Enhancement of Photovoltaic Cell by Nanofluid Cooling

2022 ◽  
pp. 1-32
Author(s):  
Hassan Salem ◽  
Ehab Mina ◽  
Raouf Abdelmessih ◽  
Tarek Mekhail
Keyword(s):  
Heat Transfer ◽  
Particle Size ◽  
Single Phase ◽  
Performance Enhancement ◽  
Photovoltaic Cell ◽  
System Optimization ◽  
Experimental Results ◽  
Key Factor ◽  
Discrete Phase ◽  
Frame Work

Abstract The cooling fluid is a key factor in cooling photovoltaic (PV) panels especially in the case of concentrated irradiance. Maintaining the panel at low temperature increases its efficiency. This paper investigates the usage of water-Al2O3 as a nanofluid for achieving the required cooling process. The particle concentrations and sizes are investigated to record their effect on heat transfer and pressure drop in the developing and developed regions. The research was performed using ANSYS CFD software with two different approaches: the single phase with average properties, and the discrete phase with the Eulerian-Lagrangian frame-work. Both approaches are compared to experimental results found in the literature. Both approaches show good agreement with the experimental results, with some advantage for the single-phase model both in processing time and in predicting heat transfer in the concentration range of 1-6% by volume. It was shown that, the heat transfer coefficient is greatly enhanced by increasing the particle concentration or decreasing the particle size. On the other hand, the usage of nanofluid causes a severe increase in the pumping power, especially with the increase in concentration and the reduction in particle size. Thus, a system optimization was suggested in order to raise the overall system efficiency for photovoltaic applications.

Experimental results of a solar space heating system with PCM: Small-scale setup and real-scale setup

2021 ◽  
Author(s):  
Nidhi Agrawal ◽  
Bhuvnesh Kumar ◽  
Bhanu Verma ◽  
Harald Mehling ◽  
Bharti Arora
Keyword(s):  
Heating System ◽  
Experimental Results ◽  
Space Heating ◽  
Small Scale ◽  
Real Scale
Sign in / Sign up

Export Citation Format

Share Document