Flame and flow structure during lean blow-off of a swirl flame.

Blow-off and flashback

Blow-off and flashback are phenomena that limit the operational range of gas turbine engines. Operating the system with too little fuel or at too high of a velocity causes the flame to blow away; too much fuel or too low velocity can cause the flame to flashback into the premixing hardware. Either of these events can be catastrophic for engine operation. Unfortunately, the underlying processes are not well understood even in simple configurations, let alone real engines.

We are using the Experimental Engine Lab's suite of high-speed laser diagnostics to simultaneously measure the flame structure and flow field dynamics during blow-off and flashback of engine-relevant swirl-flames. This allows us to explain how complex, configuration-dependent mechanisms contribute to these phenomena. The resultant data are leading to better combustors for real engines, new design guidelines, and validated simulation tools.