Large eddy simulation was utilized for the simulation of supersonic cooling jet flow filed around a blunted double cone

and the flow structures and density fluctuation characteristics were analyzed. The large eddy simulation method was based on the implicit sub-grid model

and the high-order flux limited compact scheme and explicit Runger-Kutta method were utilized for the spatial discretization and time advancing. The present simulation clearly captured the flow field discontinuity. The processes of flow becoming unstable and transiting to turbulence were predicted subtly. Besides

the characteristics of the flow field density fluctuation were obtained directly. By comparison with the none-jet state

it revealed that gas film formed by the supersonic jet can effectively cool the optical window

and the mixing layer formed by the main flow and jet flow became unstable

and transited to turbulence quickly

causing large scale turbulence structures and intense density fluctuation. In addition

the spatial development characteristics of cooling jet flow field around the whole model are obtained.