An experimental study of flame height and air entrainment of buoyancy-controlled jet flames with sidewalls

The flame height and air entrainment of jet flame from axisymmetrical source with sidewalls have been investigated in this paper. Two sizes of nozzle have been used, and seven kinds of spaces between the two sidewalls (W = 15, 20, 30, 40, 60, 80, and ∞ cm) with the same width have been considered. It is found that the flame height decreases with the increase of space between sidewalls, while the entrainment coefficient increases with it. The value of parameter C is generally inversely proportional to the hydraulic diameter of the sidewalls (D) linearly. The value of α4/5·Lf is almost a constant for the same heat release rate Q̇ under different spaces of sidewalls. A global model has been developed between α4/5·Lf and Q̇ with a linear relationship.