Mixing Layer Ignition oC Hydrogen c. TREVIÑO* and

A theoretical analysis is given for the high-temperature ignit~on in a laI~lÍnar mixing layer betweenhydrogen and air at the high temperatures characteristic of supersomc combustlOn. We analyze the most Important practical case where the temperature of the air stream is higher than that of the hy~rogen stream. In thls case the chemical reactions responsible for ignition occur in the air side of the mlXlng layer, w?ere the mixt~re is lean. A simplified reduced mechanism is found to describe the i~nition p~ocess. T.he radlca~s OH and H follow the steady-state approximation while the radical O is the cham branchmg specles. followm ~ an autocatalytic reaction with moderately large activation energy. Numerical results of th ~ governm ~ equatlOns for large values of the activation energy are presented and fr~m a sy~plified analysls, we obtam a closed form solution of the ignition distance as a function of the physlcochemlcal parameters