Simultaneous single-shot laser-based imaging of formaldehyde, OH, and temperature in turbulent flames

✍ Scribed by Stefan Böckle; Jan Kazenwadel; Thomas kunzelmann; Dong-Ill Shin; Christof Schulz; Jürgen Wolfrum

• Publisher: Elsevier Science
• Year: 2000
• Tongue: English
• Weight: 525 KB
• Volume: 28
• Category: Article
• ISSN: 1540-7489
• DOI: 10.1016/s0082-0784(00)80221-0

✦ Synopsis

Single-shot formaldehyde (CH 2 O) laser-induced fluorescence (LIF) imaging measurements in turbulent flames were performed using XeF excimer laser excitation in the transition of the A ˜1A 2 -X ˜1A 1 electronic 1 4 0 system at 353 nm. Background contributions to the CH 2 O LIF detection were assessed in spectroscopic measurements. Simultaneous two-dimensional mapping of OH LIF, CH 2 O LIF, and temperature fields was carried out in a standard Bunsen flame. The zones of peak heat release rate localized via the product of OH and CH 2 O LIF intensities correlated with areas of intermediate temperatures. In addition, singleshot imaging of the transient formaldehyde distribution was performed in a 150 kW natural gas swirl burner. Formaldehyde distributions in strongly turbulent swirl flames differed significantly from thin layers found in laminar and weak turbulent flames, indicating the presence of low-temperature chemistry in preheated gas pockets. The CH 2 O distribution measured in the swirl flame was compared with averaged fields of temperature, OH, and NO concentrations.