A concentric flow slot burner for stabilizing turbulent partially premixed inhomogeneous flames of gaseous fuels

作者：Mansour Mohy S^*; Pitsch Heinz; Kruse Stephan; Zayed Mohamed F; Senosy Mohamed S; Juddoo Mrinal; Beeckmann Joachim; Masri Assaad R

来源：Experimental Thermal and Fluid Science, 2018, 91: 214-229.

DOI：10.1016/j.expthermflusci.2017.10.021

• Slot burner
• Turbulent combustion
• Gaseous fuels
• Inhomogeneous mixtures
• OH-PLIF
• C2Hx-PLIF

Combustion of turbulent inhomogeneous mixtures of air and fuel is common in many practical systems providing improved stability for both gaseous and liquid fuels. Understanding the structure and stability of turbulent flames in this mode has been the aim of many research groups who employed special burner designs to control the fuel and air mixing process. In this work, a modified design inspired by the Wolfhard-Parker slot burner was developed for planar turbulent flames with inlet conditions that are overall lean yet either compositionally inhomogeneous or partially premixed. The new burner is referred as the Concentric Flow Slot Burner (CFSB). The stability characteristics and flame structure are investigated for methane and natural gas fuels using planar laser induced fluorescence of C2Hx and high speed PLIF-OH. The effects of the jet equivalence ratio, the level of inhomogeneity, and the Reynolds number are investigated in this work. The data show that the flames with inhomogeneous mixture are more stable than fully premixed flames. Lean flames are stabilized in the CFSB burner. Stability is significantly improved by the use of a hollow truncated rectangular pyramid nozzle at the burner exit. The reaction zone structure varies significantly in the current burner from thin structures in rich flames to distributed with thick preheat zones in lean flames. The effect of the level of inhomogeneity on the reaction zone structure is presented and discussed. The new CFSB burner is able to generate a wide range of turbulent planar flames spanning the entire range from non-premixed to fully premixed flames. In addition, the high stability level of the burner allows for the study of highly turbulent flames of practical interest.

• 出版日期2018-2