COMPUTATIONAL AND EXPERIMENTAL STUDY OF A TWO-SECTION POROUS BURNER

Abstract

In this study, experiments and computations were conducted on a two-section porous burner operated on propane/air and methane/air mixtures. The burner consisted of an upstream section of reticulated yttria-stabilized zirconia with 23.6 pores per centimeter (ppc) and a downstream section of 3.9 ppc. Measurements of axial and radial temperatures, pressure drop, and emissions levels were recorded. The predictions from a one-dimensional transient mathematical model with full chemistry were compared to experimental results. Both computations and experiments showed that the stable operating range increases with equivalence ratio. The predicted upper limit agrees well with experiments but the lower limit is somewhat overpredicted. The average temperature in the exhaust stream increases with both inlet velocity and equivalence ratio and is relatively uniform across the burner. Pressure drop is much greater for reacting flows than cold flow and generally increases with inlet velocity. Measured levels of unburned hydrocarbons, oxides of nitrogen, and carbon monoxide are low.

Keywords:

• porous burner
• emissions
• premixed flame
• excess enthalpy

This work was supported by the Office of Naval Research through Dr. Gabriel Roy and also by the Independent Research and Development Program at the Applied Research Laboratories, University of Texas at Austin. The authors would also like to acknowledge Porvair Corporation for supplying the porous ceramics for these experiments. They also thank Mr. John Witton of Cranfield University for his helpful discussions.