TY  - EJOU
AU  - He, Lu 
AU  - Zhou, Yuhang 
AU  - Zhu, Guoqing 

TI  - Study	on	the	Influence	of	the	Longitudinal	Position	of	the	Fire	Source	on	 the	Movement	Behavior	of	the	Asymmetric	Flow	Field	in	Tunnel	Fire
T2  - The International Conference on Computational \& Experimental Engineering and Sciences

PY  - 2023
VL  - 26
IS  - 2
SN  - 1933-2815

AB  - The	 longitudinal	 position	 of	 the	 fire	 source	 is	 one	 of	 the	 key	 parameters	 affecting	 the	 flow	 field	
characteristics	in	a	long-distance	tunnel.	In	this	paper,	a	series	of	numerical	simulations	were	carried	out	to	
analyze	the	influence	of	the	longitudinal	position	and	the	heat	release	rate	(HRR)	on	the	induced	airflow	on	
both	sides	of	the	fire	source and	the	smoke	movement	behaviors	characteristics	in	the	long-distance	tunnel.	
It	is	found	that	under	the	induction	of	thermal	pressure,	an	asymmetric	induced	air	flow	is	formed	near	the	
fire	 source,	 resulting	in	asymmetric	 dynamic	 parameters	 of	 ceiling	jet.	The	wind	 speed	 of	 the	 ceiling	jet	
gradually	decreases	during	the	movement	to	the	tunnel	outlet,	and	the	inertia	force	and	turbulence	intensity	
are	continuously	weakened.	At	a	certain	position,	the	ceiling	jet	will	be	reversely	entrained	by	the	induced	
airflow.	The	mass	flow	rate	and	thickness	of	the	ceiling	jet	show	the	characteristics	of	increasing	first	and	
then	decreasing	in	the	longitudinal	direction.	In	addition,	A	theoretical	prediction	model	for	the	mass	flow	
rate	of	the	asymmetric	flow	field	is	proposed.
KW  - Tunnel	fire;	longitudinal	position	of	fire	source;	asymmetric	induced	air	flow;	flow	field

DO  - 10.32604/icces.2023.08939