Based on partition control technology and CFD numerical simulation

the easily controllable design methods of double S-nozzle type surface were developed

and the flow characteristics of double S-nozzle were simulated.With message passing interface (MPI) parallel algorithm and discrete transfer method

the software of infrared radiation characteristics was programmed.The infrared radiation characteristics of double S-nozzle were computed by the software.The infrared radiation characteristics were compared with those of axisymmetric convergent nozzle with the same inlet and outlet areas.The results show that the infrared radiation intensity of wide detection surface of double S-nozzle is less than that of the narrow detection surface

with the biggest margin up to 80%.The infrared radiation intensity on each probing direction is lower than that of axisymmetric convergent nozzle

especially on the probing direction between 30° and 40° in the wide detection surfaces

and the infrared radiation intensity of double S-nozzle is lower 30% than that of axisymmetric convergent nozzle.