Experimental observation and numerical simulation of transient “stress fangs” within flowing molten polyethylene

2001 ◽  
Vol 45 (6) ◽  
pp. 1261-1277 ◽  
Author(s):  
K. Lee ◽  
M. R. Mackley ◽  
T. C. B. McLeish ◽  
T. M. Nicholson ◽  
O. G. Harlen
Keyword(s):  
Numerical Simulation ◽  
Experimental Observation ◽  
Transient Stress

Numerical Simulation on Failure Process of Internally Pressured Cylindrical Shell Subjected to Wedge Impact

2006 ◽  
Vol 324-325 ◽  
pp. 523-526 ◽  
Author(s):  
Gang Chen ◽  
Qing Ping Zhang ◽  
Zhong Fu Chen ◽  
Si Zhong Li ◽  
Yu Ze Chen
Keyword(s):  
Numerical Simulation ◽  
Cylindrical Shell ◽  
Experimental Observation ◽  
Impact Loading ◽  
Cylindrical Shells ◽  
Failure Process ◽  
Dynamic Failure ◽  
Local Impact ◽  
Wedge Impact ◽  
Numeral Simulation

Cylindrical shell is a kind of common used structure in engineering. Interest in the response of cylindrical shells to local impact loading has increased over the last few years. A structure always endures working load more or less. For a cylindrical shell, the working load commonly is internally pressure. In this paper, a numeral simulation of wedge block impact internally Pressured cylindrical shell was carried out. The dynamic failure process of the structure was obtained. The consistency between experimental observation and numerical simulation is satisfactory.

Fire whirls due to surrounding flame sources and the influence of the rotation speed on the flame height

2007 ◽  
Vol 583 ◽  
pp. 313-345 ◽  
Author(s):  
RUI ZHOU ◽  
ZI-NIU WU
Keyword(s):  
Numerical Simulation ◽  
Boundary Layer ◽  
Experimental Observation ◽  
Vertical Velocity ◽  
Rotation Speed ◽  
Flame Height ◽  
Pressure Reduction ◽  
Air Stream ◽  
Rising Time

In this paper, we use numerical simulation and laboratory experimental observation to show that fire whirls can be generated spontaneously through the interaction between a central flame and surrounding organized or randomly distributed flames. The momentum of the air stream entrained by the main flame decreases as it crosses a surrounding flame, so that the main flame rotates if surrounding flames are arranged in such a way as to block the passage of the air stream directed towards the centre of the main flame and to favour flows in a particular circumferential direction. An analysis is performed to study the role of the rotation speed in the flame height. It is found that the flame height initially decreases to a minimum owing to the inflow boundary layer wind reducing the initial vertical velocity of gas for low rotation speed and to entrainment enhancement reducing the rising time, and then it increases owing to the pressure reduction at the centre of the rotating vortex and entrainment suppression extending the rising time.

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