Visualization of dilute hydrogen jet flame in air flow

Article type: Research Article

Authors: Chinone, S. | Fujisawa, N.

Affiliations: Department of Mechanical Engineering, Niigata University, 8050 Ikarashi 2, Niigata, 950-2181, Japan

Abstract: The structure of hydrogen jet flame diluted by CO_2 in air flow is studied by various visualization techniques, such as schlieren, direct photograph, tracer injection and reactive Mie scattering method, which allow understanding of the influence of CO_2 on the characteristics of the hydrogen jet flame. The experimental result indicates that the flame structure consists of laminar fuel jet and surrounding reaction zone near the nozzle exit. When the CO_2 fraction is increased, the width of the fuel jet grows and the reaction zone is reduced in size. These observations are further confirmed by quantitative measurements of temperature and velocity fields in the flame, which are evaluated by thermocouple and particle image velocimetry (PIV), respectively. These results indicate that the flame temperature is decreased and the flow rate of the fuel jet is increased by the influence of diluents, which are due to the reduced calorific value and larger density of fuel, respectively.

Keywords: Flow visualization, Diffusion flame, Hydrogen, PIV, Temperature, Velocity

Journal: Journal of Visualization, vol. 7, no. 4, pp. 291-298, 2004