In order to investigate the characteristics of axisymmetric cylindrical isolator under different back pressures

the flow field of the isolator was simulated with different inviscid flux schemes and turbulence models. Compared with the experimental data

the most suitable model and scheme were chosen. Three-dimensional simulations of the isolator and combustor were employed to study the flow field structure

exit parameter and shock train under different back pressure ratios. The limit back pressure was found. The structures of the shock train under two kinds of back pressure were compared. Results show that the inviscid flux scheme and turbulence model

which are critical for the isolator simulation

have a significant impact on the structure and length of the shock train. The parameter of the isolator exit is affected by the back pressure. When the exit of the isolator is in the mixing region

the static pressure distribution is more uniform. And when the exit is in the shock train region

the pressure is non-uniform. For this axisymmetric cylindrical isolator and combustor

there is no obvious difference on structure and initial position of the shock trains respectively induced by the combustion back pressure and cold back pressure.