Influence of jet blast deflector with fold angle on supersonic jet flow

  Objectives  In order to study the performance of Jet Blast Deflector(JBD)and its influence on the surrounding flow field during the takeoff or ground testing of the fighter, this paper studies the typical axisymmetric convergent-divergent nozzle and the JDB with fold angle of the engine.

  Methods  Through FLUENT software, the numerical simulation of the upstream and downstream flow fields of the JDB after the jet flow is carried out with different horizontal distance from the nozzle exit section to the spindle of JDB, and different deflection and fold angles of JDB, to analyze the thermodynamic parameters of JDB surface and the distribution of the surrounding flow field.

  Results  It is shown that the longer the horizontal distance from JDB to the rear of the nozzle is, and the smaller the deflection angle is, the lower the airflow pressure and temperature on the JDB will be. And the farther the horizontal distance is, and the larger the deflection angle is, the lower the velocity and temperature of surrounding flow field will be. The fold angle of JDB can effectively strengthen the role of JDB in controlling and guiding the air flow and increase the safe area after the JBD.

  Conclusions  The calculation results provide guidance for the research and development of JDB.