Structural Parameters Effects on Lean Blowout Performance and Prediction Method for Piloted Vaporization Flameholder

To widen the lean blowout boundary of piloted vaporization flameholder, the impacts of length of skirt plate and head opening ratio on the lean blowout performance were investigated by experiment with the flow condition of Ma=0.14 ~ 0.3 and T=483K firstly. Secondly, the method of cold flow field numerical simulation combined with combustion loading parameter of piloted vaporization flameholder was used to predict lean blowout performance of piloted vaporization flameholder. It is found that LBO fuel/air ratio of the piloted vaporization flameholder with skirt plate length of 32.5mm is less than the piloted vaporization flameholder without skirt plate, and the combustion loading parameter of it is reduced because of the reduction of the mass flow rate passing through the head of flameholder and increasing of the local recirculation zone volume. The combustion loading parameter is increased for the flameholder with bigger head opening ratio owing to more mass flow rate passing through the head of flameholder, and the LBO fuel/air ratio of the piloted vaporization flameholder with head opening ratio of 6.4% is less than the piloted vaporization flameholder with head opening ratio of 9%. The dimensionless combustion loading parameter fits linearly with the local LBO fuel/air ratio, which could be used to predict LBO for different structural piloted vaporization flameholder.