Methane hydrogen hybrid turbulent combustion phenomena in a high temperature low oxidizer

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The effect of oxidizer preheating and dilution levels of fuel and oxygen on the combustion phenomena were investigated experimentally and numerically on an opposite turbulent flow fields. The oxidizer preheating and dilution levels are characterized by the magnitude of stoichometric mixture fraction (Fst). As overall feature of the extinction limits, the flame can be maintained to increase in the fuel concentration of opposite side, even when one side fuel concentration is reduced. Obviously, the turbulence conditions affect significantly on the extinction limits. The extinction limit is not influenced on the turbulence added in the LPF side. However, in the case of the turbulence added in the LDF side, the extinction limits is increased. In the regime of F_<st><0.5, the extinction limits of the laminar flame and turbulent flame are significantly dividing from the laminar flames.Near the extinction condition, the local quenching phenomena can be observed. If the large area of the local quenching occurs in the stagnating point, the local quenching area developed to the global extinction. However, the local quenching is not always trigger to develop the global extinction. Most of cases, the flame can recover from the local quenching phenomena. There are two distinct the local quenching recovery mechanism. One is the local quenching, which occurs at the stagnation point. In this case, the LPF propagates into the local quenching area. Then the flame can be recovered from the local quenching phenomena. The other local quenching occurs at the outside form the stagnating point. In this case, the local quenching area is drifted with the diverging flow from the stagnating point. The flame can be automatically recovered in accordance with the opposite flow properties.