Investigation of the relation between flame volume and LBO limits for a swirl-stabilized combustor

The prediction of lean blowout (LBO) limits is very important in the combustion design process. Several LBO semi-empirical correlations are proposed to estimate the LBO performance for combustors. Among these correlations, Lefebvre´s model is employed extensively. However, the model can not embody the effects of the variations of dome geometry and primary holes arrangement on LBO limits. In order to improve Lefebvre´s model, a new physical model is established and flame volume (FV) concept is proposed according to the flame observations. Then an improved correlation (i.e. FV model), which relates the flame volume to LBO limits, is derived to consider the effects of the variations of dome geometry and primary zone configurations. The FV model is verified by lots of visual experiments. The results reveal that the prediction accuracy of FV model is much higher than that of Lefebvre model.