Abstract: Based on the the liquid rocket motor,the whole sphere flow model was proposed for the supersonic spray for the KY-HVO(A) F system.The velocity and temperature distributions were modeled for the high velocity oxygen fuel(HVOF) and high velocity air fuel system,and the sub expanding and super expanding characteristics were presented respectively.The HVOF system has 8 mach diamonds in the calculated result,and the actual flame has 8-9 mach diamonds,so the pulse in the spray process can be analyzed well.The similar characteristics were shown in the velocity distributions.