Numerical simulation of hydrogen-air boundary layer flows augmented by catalytic surface reactions

Wai Cheung Timothy Tong, Mohsen M. Abou-Ellail, Yuan Li

Research output: Chapter in book / Conference proceedingConference article published in proceeding or bookAcademic researchpeer-review

1 Citation (Scopus)

Abstract

Catalytic combustion of hydrogen-air boundary layers involves the adsorption of hydrogen and oxygen into a platinum coated surface, chemical reactions of the adsorbed species and the desorption of the resulting products. Re-adsorption of some produced gases is also possible. The catalytic reactions can be beneficial in porous burners and catalytic reactors that use low equivalence ratios. In this case the porous burner flame can be stabilized at low temperatures to prevent any substantial gas emissions, such as nitrogen oxides. The present paper is concerned with the numerical computation of heat transfer and chemical reactions in hydrogen-air mixture boundary layers that flow over platinum coated hot plates. Chemical reactions are included in the gas phase as well as on the solid platinum surface. In the gas phase, eight species are involved in 26 elementary reactions. On the platinum hot surface, additional surface species are included that are involved in 14 additional surface chemical reactions. The platinum surface temperature is fixed, while the properties of the reacting flow are computed. The flow configuration investigated in the present paper is that of a parallel boundary layer. Finite-volume equations are obtained by formal integration over control volumes surrounding each grid node. Hybrid differencing is used to ensure that the finite-difference coefficients are always positive or equal to zero to reflect the real effect of neighboring nodes on a typical central node. The finite-volume equations are solved, iteratively, for the reacting gas flow properties. On the platinum surface, surface species balance equations, under steady-state conditions, are solved numerically. A non-uniform computational grid is used, concentrating most of the nodes in the boundary sub-layer adjoining the catalytic surface. The computed OH concentration is compared with experimental and numerical data of similar geometry. The obtained agreement is fairly good, with differences observed for the location of the peak value of OH. Surface temperature of 1170 K caused fast reactions on the catalytic surface in a very small part at the leading edge of the catalytic flat plate. The computational results for heat and mass transfer and chemical surface reactions at the gas-surface interface are correlated by non-dimensional relations.
Original languageEnglish
Title of host publication2007 Proceedings of the ASME/JSME Thermal Engineering Summer Heat Transfer Conference - HT 2007
Pages949-958
Number of pages10
Volume1
DOIs
Publication statusPublished - 1 Dec 2007
Externally publishedYes
Event2007 ASME/JSME Thermal Engineering Summer Heat Transfer Conference, HT 2007 - Vancouver, BC, Canada
Duration: 8 Jul 200712 Jul 2007

Conference

Conference2007 ASME/JSME Thermal Engineering Summer Heat Transfer Conference, HT 2007
CountryCanada
CityVancouver, BC
Period8/07/0712/07/07

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Mechanical Engineering
  • Condensed Matter Physics

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