An analysis of the ignition of slot-injected gaseous hydrogen in a supersonic air stream

✍ Scribed by J.A. Schetz; S. Favin

• Publisher: Elsevier Science
• Year: 1967
• Tongue: English
• Weight: 897 KB
• Volume: 11
• Category: Article
• ISSN: 0010-2180
• DOI: 10.1016/0010-2180(67)90060-0

✦ Synopsis

The effects of an initial air-side boundary layer on the ignition of slot-injected gaseous hydrogen by a hot :apersonlc air stream are treated analytically. Essentially, the treatment is based on the assumption of unit te:bulent Prandtl and Lewis numbers, a ma~ flow difference model for the eddy viscosity and a lincarization of the boundary layer equations performed in the Howarth-Dorodnitzin plane. Once the flo~," field is determined, an isotherm and streamline pattern is constructed. These patterns can be examined to see ff regions exist with both T > T~ and fuel concentration above the lean ignition limit, if not, ignition is ~ot possible. If these conditions are met in a region, then the streamline through this a~ea can be followed downstream to see if sufftcient time for ignition is available befo~ passing into a colder or leaner region, Previousl7 determin~:d ignition delay correlations are used to estimate an ignition delay time which is then compared to the residence time of a fluid particle in the 'hot spot" in order to as~ss the likelihood of ignaion. The results of paramelric numerical examplcs are presented and discussed to disphy the influence of the various parataeters.