Combustion Science and Technology, Vol.186, No.2, 120-138, 2014
A COMPARATIVE STUDY ON FREE JET AND CONFINED JET DIFFUSION FLAMES OF LIQUID ETHANOL FROM SMALL NOZZLES
A combined experimental and numerical study has been conducted to compare the characteristics of free jet flames and confined jet flames from a small ceramic tube burner using liquid ethanol as fuel. The visualization results show that the flame shapes between the free jet flame and the confined jet flame have some differences. An obvious liquid-vapor interface has been found for the confined jet. Numerical results of flame lengths and flame temperature show reasonable agreement with the experimental data within the present parameter ranges. At the same liquid ethanol flow rate, the flame length of confine jet is smaller than that of free jet. For the confined jet, the heat loss is smaller; the flame temperature is higher, so the enhanced diffusion results in a shorter length.