skip to main content

Title: Effects of CO addition on the characteristics of laminar premixed CH{sub 4}/air opposed-jet flames

The effects of CO addition on the characteristics of premixed CH{sub 4}/air opposed-jet flames are investigated experimentally and numerically. Experimental measurements and numerical simulations of the flame front position, temperature, and velocity are performed in stoichiometric CH{sub 4}/CO/air opposed-jet flames with various CO contents in the fuel. Thermocouple is used for the determination of flame temperature, velocity measurement is made using particle image velocimetry (PIV), and the flame front position is measured by direct photograph as well as with laser-induced predissociative fluorescence (LIPF) of OH imaging techniques. The laminar burning velocity is calculated using the PREMIX code of Chemkin collection 3.5. The flame structures of the premixed stoichiometric CH{sub 4}/CO/air opposed-jet flames are simulated using the OPPDIF package with GRI-Mech 3.0 chemical kinetic mechanisms and detailed transport properties. The measured flame front position, temperature, and velocity of the stoichiometric CH{sub 4}/CO/air flames are closely predicted by the numerical calculations. Detailed analysis of the calculated chemical kinetic structures reveals that as the CO content in the fuel is increased from 0% to 80%, CO oxidation (R99) increases significantly and contributes to a significant level of heat-release rate. It is also shown that the laminar burning velocity reaches a maximum value (57.5more » cm/s) at the condition of 80% of CO in the fuel. Based on the results of sensitivity analysis, the chemistry of CO consumption shifts to the dry oxidation kinetics when CO content is further increased over 80%. Comparison between the results of computed laminar burning velocity, flame temperature, CO consumption rate, and sensitivity analysis reveals that the effect of CO addition on the laminar burning velocity of the stoichiometric CH{sub 4}/CO/air flames is due mostly to the transition of the dominant chemical kinetic steps. (author)« less
Authors:
 [1] ; ; ;  [2] ;  [3]
  1. Advanced Engine Research Center, Kao Yuan University, Kaohsiung County, 821 (China)
  2. Department of Aeronautics and Astronautics, National Cheng Kung University, Tainan, 701 (China)
  3. Department of Mechanical Engineering, Chung Hua University, Hsinchu, 300 (China)
Publication Date:
OSTI Identifier:
21137921
Resource Type:
Journal Article
Resource Relation:
Journal Name: Combustion and Flame; Journal Volume: 156; Journal Issue: 2; Other Information: Elsevier Ltd. All rights reserved
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; CARBON MONOXIDE; METHANE; AIR; LAMINAR FLAMES; VELOCITY; JETS; STOICHIOMETRY; OXIDATION; SIMULATION; COMBUSTION PROPERTIES; COMPARATIVE EVALUATIONS; SENSITIVITY ANALYSIS; HEAT LOSSES; CONSUMPTION RATES; COMBUSTION KINETICS Blended fuels; Premixed opposed-jet flames; Numerical simulation