“…Whereas screech frequency is controlled by the feedback acoustic waves, the screech intensity is governed primarily by the characteristics of the downstream propagating flow disturbances and their interaction with the shock-cell structures. Several detailed measurements [10,12,15,[19][20][21][22][23] and numerical viscous simulations [10,[24][25][26][27][28][29] have been reported and served to throw light on the subject. The experimental description of A-D mode switch (A1 , A2 , B, C, D) according to the jet operating parameters represents a notable step [12].…”