Comparative analysis of methods for heat losses in physically-derived reduced-order manifolds

A. Cody Nunno, Temistocle Grenga, Michael E. Mueller

Research output: Contribution to conferencePaper

Abstract

Heat loss substantially modifies turbulent combustion processes, especially the formation of pollutants such as nitrogen oxides, which are strongly temperature sensitive. To account for the effects of heat loss in Large Eddy Simulation (LES) using a reduced-order manifold approach, thermochemical states are computed via a priori 1-D premixed flame calculations over a range of reduced enthalpy states. Two basic approaches are explored for generating these reduced enthalpy states, which are compared to assess any effects on turbulent flame structure and emissions. In the first approach, a variable heat loss source term is introduced into the 1-D flame solutions by mimicking a real heat loss to reduce the post-flame enthalpy. In the second approach, fuel and oxidizer are converted to products in the unburned gases at a constant temperature to produce reduced enthalpy in the entire 1-D flame solution. The two approaches are compared in methane-air piloted turbulent premixed planar jet flames that maintain a constant adiabatic flame temperature but experience differing radiation heat losses. The results indicate that the manner in which the heat loss is accounted for in the manifold is of secondary importance compared to other model uncertainties such as the chemical mechanism.

Original languageEnglish (US)
StatePublished - Jan 1 2017
Event10th U.S. National Combustion Meeting - College Park, United States
Duration: Apr 23 2017Apr 26 2017

Other

Other10th U.S. National Combustion Meeting
CountryUnited States
CityCollege Park
Period4/23/174/26/17

All Science Journal Classification (ASJC) codes

  • Chemical Engineering(all)
  • Physical and Theoretical Chemistry
  • Mechanical Engineering

Keywords

  • LES
  • NOx
  • Radiation
  • Turbulent premixed flames

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  • Cite this

    Cody Nunno, A., Grenga, T., & Mueller, M. E. (2017). Comparative analysis of methods for heat losses in physically-derived reduced-order manifolds. Paper presented at 10th U.S. National Combustion Meeting, College Park, United States.