Bulk and wall flame quenching in nonuniform concentration fields

✍ Scribed by N. Ishikawa

• Publisher: Elsevier Science
• Year: 1984
• Tongue: English
• Weight: 761 KB
• Volume: 56
• Category: Article
• ISSN: 0010-2180
• DOI: 10.1016/0010-2180(84)90059-2

✦ Synopsis

Schlieren photographic experiments on laminar flame quenching both in bulk gases and on a fiat wall have been conducted in nonuniform concentration fields that simulate local gaseous conditions in an engine. The combustion takes place at atmospheric pressure and room temperature through a combustible layer formed in an interface between layers of fuel and air. Bulk flame quenching is observed in methane/air mixtures under conditions such as increased concentration gradient, reduced ignition energy, and addition of nitrogen in methane. This raises the possibility that any causes, even turbulence, generating spatial nonuniformity in concentration in an engine may result in a decrease in combustion efficiency. That is. bulk flame quenching of the present type may contribute appreciably to unburned hydrocarbon formation. Both head-on wall quenching and side-on quenching were observed for methane/air and hydrogen/air mixtures, respectively. The results show that the present combustor may be capable of providing proper data reduction of the wall flame quench layer thickness in practical mixtures.