An experimental study of the merging probability of double buoyancy-controlled jet flame

ABSTRACT

This article presents an experimental investigation on the merging probability of buoyancy-controlled jet flames. Two rectangular jet nozzles with different aspect ratios and heat release rates were studied in the open space. The nozzles of the same area with dimensions of 1.5 × 24, 3 × 12, and 6 × 6 mm were used in this article. It is found that the merging probability increases with the heat release rate and decreases with the space between these two nozzles. A model to predict the merging probability has been developed, which is proportional to a dimensionless parameter linearly within a certain scope.

KEYWORDS:

• merging probability
• jet flame
• heat release rate
• double flame

Nomenclature

	=	The length of rectangular nozzle
	=	The width of rectangular nozzle
	=	Specific heat capacity of air
	=	Hydraulic diameter
	=	Gravitational acceleration
	=	The pressure of flame region
	=	The pressure of additional region
	=	Ambient pressure
	=	Merging probability
	=	Probability of the visible flame
	=	Heat release rate
	=	Dimensionless heat release rate based on nozzle diameter
	=	Dimensionless heat release rate based on equivalent nozzle diameter
	=	Time
	=	Time
	=	Temperature
Greek symbols	=
	=	Air density

Funding

This work was supported by the National Natural Science Foundation of China [51408181,51504282,51676002];the Opening Foundation of State Key Laboratory of Fire Science, University of Science and Technology of China [HZ2017-KF01];the Fundamental Research Funds for the Central Universities [JZ2016HGBZ0766,JZ2017HGTB0208];

Highlights

The merging probability of double jet flames has been investigated.

The merging probability increases with the increase of heat release rate.

The merging probability decreases with the increase of space between these nozzles.

A model to predict the merging probability has been developed

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [51408181,51504282,51676002];the Opening Foundation of State Key Laboratory of Fire Science, University of Science and Technology of China [HZ2017-KF01];the Fundamental Research Funds for the Central Universities [JZ2016HGBZ0766,JZ2017HGTB0208];