Performance analysis of single expansion ramp nozzle with passive cavity

Under over-expansion condition, the internal three-dimension flow field and performance of single expansion ramp nozzle (SERN) with large expansion ratio were explored, the Effect of passive cavity on the SERN was investigated. Results show: for the baseline SERN, in low pressure ratio range of 4 to 10, the axial thrust coefficient predicted by two dimensional model is larger than that it has for the three-dimensional model with sidewall. The passive cavity promotes the flow separation on the expansion ramp of SERN, and Effects the pressure distribution of the expansion ramp, as a result, the axial thrust coefficient can be improved. Two different porous plate models are investigated under same percent of porosity condition. Results show different porous plates have the same Effects on the passive cavity SERN.