Experimental research of active control optimization on a 3/4 open-jet wind tunnel’s jet section

Abstract

A 1:15 3/4 open-jet scaled wind tunnel was used for experimental test. By arranging the synthetic jet actuator around the nozzle, the experimental method was used to analyze the flow field after the active flow control was implemented. The effects of the excitation frequency fJ of different input signals and the excitation velocity V0 of different jet nozzles on the jet shear layer and the flow field in the test section were studied. The obtained results showed that when the excitation frequency of the synthetic jet actuator (fJ) was 40 Hz and excitation velocity (V0) equaled to 10 m/s, the turbulence intensity of each measurement point was the highest among all excitation frequencies, and the flow field had a peak near 19–20 Hz, which was the sensitive frequency of buffeting. The highest power spectral density of this frequency peak was nearly ten times higher than the original working condition, which meant that this control scheme will aggravate the buffeting phenomenon. For fJ = 140 Hz and V0 = 15 m/s, it only had a high PSD peak at 19–20 Hz near the measurement point 15 of the collector. The overall control effect of this scheme is better than other schemes. Therefore, it can significantly suppress the buffeting phenomenon of the wind tunnel and improve the flow field quality of the test section.

Keywords

• Buffeting
• Shear layer of jets
• Synthetic jet actuator
• Scaled wind tunnel test