Presented wet combustion chamber concept contains several integrated elements, which altogether form a prototype able to reduce extremely high oxy-combustion temperatures (up to 2800ᵒC) in an elevated pressure above 10 bars. To enable such capability, liquid water is supplied directly into the combustor flame zone. This is obtained with the front spray and water penetration through the two separate liner segments, which are made of the ceramic matrix composite (CMC) porous medium. This material was developed by the aerospace industry to take advantage of the ceramic heat resistance and low density while reducing the disadvantage of monolithic ceramic brittleness. Taking various interactions into account, analysed model couples rapid oxy-combustion process with the instant liquid water evaporation. Particularly important phenomena occurs at the surfaces of water droplets penetrating the flame with the axial velocity of 100 m/s. Rapid evaporation of each of them induce significant mixing force driven by the local thermal gradients. For the nominal case, 3D results were validated against the 0D calculations. While the nominal water mass split is 14% at the front plus 86% at the liner, other supply ratios were taken into account and are reported in the results section. Combustion process was modelled with GRI-Mech 3.0 mechanism.