Suppressing Methods of the Pressure Fluctuation in Open Jet Wind Tunnels

Due to the distinctive structure of test section, open jet wind tunnel generates low-frequency pressure fluctuations (LFFs) within range typical speeds. These significantly compromise quality flow field in section. The evolution and vortex is analysed through improved delayed detached eddy simulations (IDDES). LFFs control mechanism Jilin University are then studied. interaction between large-scale shedding at nozzle exit collector forms edge feedback, which main reason for fluctuation. According feedback mechanism, suppressed using throat gap by improving shapes. results show that increase length can alleviate accumulation inside collector. change shapes impact area time incoming flow, or produce permanent affect shape collector, allows LFFs. This study lays a solid foundation further comprehension aerodynamic characteristics tunnels.