Experimental and computational investigation of novel vertical tail buffet suppression method for high sweep delta wing

Our research aim is to investigate the buffet alleviation effect of static or vibrating bulges attached on the forebody surface of the model. Experiments and numerical simulations on a model consisting of a sharp-edged, 70°-leading edge sweep delta wing and twin swept back vertical tails were conducted. Models with different bulges were tested and computed at 10 and 20 m/s of free stream velocity at angles of attack ranging from 20°-50°. Dynamic strain gauge and multichannel data acquisition and analysis system were employed for the measurement of unsteady root strain on the vertical tails. Experimental and computational results show that both static and vibrating bulges behave effectively as a novel tool to alleviate tail buffet, and the alleviation effect depends largely on the vibrating frequency. Besides, one-sided bulge can only alleviate the buffeting response for the tail of the same side, and it has no obvious alleviation effect for the opposite tail. Results of the spectral analysis reveal that there are generally three peaks of spectral density for aircrafts of this configuration, and bulges used in this paper could alleviate tail buffeting, but the total lift and drag of the whole model show no obvious deviation compared to the base model and the dominant frequency of the vibration of the tails has not shifted.