Large Eddy Simulation/Conditional Moment Closure (LES-CMC) simulations of non-premixed turbulent hydrogen jet in oxy-combustion regimes are performed. The fuel is pure hydrogen and the oxidiser is a mixture O_2/H_2O with mass fraction of water vapour in the range Y_(H_2O) = 0.1 - 0.9. The fuel issues into a hot oxidiser stream (1030K-1045K), auto-ignites and the flame propagates through the domain. The problem analysed offers new challenges to combustion modelling as depending on O_2 content in the oxidiser stream the combustion process may be strongly unsteady and on the border of stability and flammability limits. It is shown that LESCMC is well suited for such studies. We analyse the auto-ignition and forced ignition processes followed by flame propagation and stabilisation phases. The results obtained show that the content of Y_(H_2O) directly affects the flame size and its lift-off height. It was observed that for low content of water vapour the auto-ignition time is a linear function of Y_(H_2O), whereas the axial locations of auto-ignition spots increase with Y_(H_2O) content.
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