Aerodynamic Layout Optimization Of The Device In Subsonic High Altitude Simulated Free Jet Test

The velocity distribution in the free jet core is uniform when the air flow with a uniform velocity is injected into the infinite space. The characteristics of free jet are used in high altitude simulated free jet test. The entrance of inlet is placed in the free jet core to simulate the flow state of the entrance of inlet in real flight environment.In the subsonic high altitude simulated free jet test, the inlet will have an impact on the flow field in front of it when the inlet is placed in the free jet core region. It will have an impact on nozzle when the distance between inlet and nozzle is too close. When the distance between inlet and nozzle increases, there are some concerns about that the inlet will shift out from free jet core region. Therefore, it is needed to find the optimal inlet and nozzle distance, which is the most close to the real flight environment. When simulating different flight attitude angles, there are different optimal distances between the inlet and nozzle of the free jet test which make the results closest to real flight environment. Thus to consider the distance between the inlet and nozzle, so at the inlet position unchanged, it can be a more realistic flight environment.The method of computational fluid dynamics(CFD) was used to determine the dimensionless distance between the inlet and nozzle, it can simulate more realistic flight environment at gestures of different angles when it is 0.72. Discussed the simulation results under the relationship of different engine traffic and the distance between inlet and nozzle, determined when the flow coefficient is 1, the free jet test results are closest to real flight environment. At the same time, the influence of the inlet overflow and the secondary flow on the flow field is studied, and the rational aerodynamic layout in the test cell is determined.