Resonance and the Underlying Coherent Structures in Supersonic Round Twin Jets

Emitted from aircraft travelling at supersonic speeds, screech tones are high-amplitude, discrete-frequency, and can damage the surrounding aircraft structure. To mitigate their impacts, a better understanding of how they arise is required. This thesis models the screech tones present in aircraft with a round twin-exhaust configuration. New insights into their generation, and the behaviours of the components generating them, are presented. In particular for low supersonic velocities, and as the two round exhausts are brought closer together.