• [2013-02-28]

  Premixed Hydrogen Flames - Instability Formation and Self-Acceleration

Speaker： Prof. Grunde Jomaas 

Host: Prof. Zheng Chen   Time：15:30 pm

Date：March 4, 2013

Venue：Room 210, COE Building No.1

  Abstract:   High-fidelity experiments were conducted at Princeton University to determine flame propagation velocities, both normal and accelerated, for outwardly propagating spherical flames in a dual-chamber design that allows near-constant experimental pressures up to 60 atmospheres. The flamefront movement was monitored using schlieren cinematography and recorded with a high-speed digital camera. A wide variety of fuels were tested, including hydrogen (both in air and in pure oxygen), syngas and DME. Cellular instabilities, spiral waves and target patterns over the propagating flame surfaces of hydrogen flames were observed, and could be explained by existing instability theory. The frames below give a preview of different hydrogen flame appearances for a range of concentrations and pressures. In the talk, it will be emphasized that all the different experimental observations are important when it comes to creating a complete map, and thereby understanding, of the instabilities in an appropriate parameter space.