LAUSR

Acoustic waves from a rocket exhaust jet cause the intense acoustic loading. Because the exhaust jet impinges on a flame deflector at liftoff of a launch vehicle, an adequate understanding of the acoustic phenomena from a supersonic impinging jet is required for prediction and reduction of the level of the acoustic loading. The previous numerical studies on a supersonic jet impinging on an inclined flat plate [e.g., Tsutsumi et al. AIAA 2014-0882; Nonomura et al. AIAA J. 54(3), 816-827 (2016)] suggested that the plate angle has a large impact on the characteristics of the acoustic waves from the impingement region. In the present study, experiments were carried out to discuss the effect of the plate angle on this acoustic phenomenon. By applying the acoustic-triggered conditional sampling to the schlieren visualization movies, which was proposed by the authors [AIAA 2016-2930], the phenomena around the impingement region were observed in detail. The results revealed that the plate-angle variation leads to...