Numerical simulation is performed to study the flowfield in a cylindrical ramjet combustor using time-dependent compressible Euler solver based on FCT(Flux-Corrected Transport) algorithm. We have changed the length of the inlet and combustor to study the interaction between the vortex flow and the acoustics of the inlet and combustor. There are strong coupling between the flowfield and the acoustics of axisymmetric inlet and combustor. Vortex roll-up is observed near the backward-facing step at the first-longitudinal mode frequency of the combustor. The location and the area of the exit nozzle influences the flow pattern of the inlet and combustor. Analysis of the time-mean quantities shows that vortices are the main contributor to the transport of mass and momentum.
