Experimental investigation of screech by an underexpanded supersonic jet with forward flight effect

Benoît André (1) , Thomas Castelain (1) , Christophe Bailly (1) , Daniel Juvé (1)

1 LMFA - Laboratoire de Mecanique des Fluides et d'Acoustique

A coaxial supersonic facility has been upgraded in the anechoic room of the Centre Acoustique (LMFA, Ecole Centrale de Lyon) to reproduce a supersonic fan flow in forward flight. This paper first presents this new facility and some validation tests. A and B screech modes are characterized. Near-field microphones can well discriminate these two modes. A chaotic behaviour is found for mode B, which cannot be explained by mode switching. The effect of secondary flow on screech is essentially a decrease in frequency. Frequency jumps and hysteresis have also been observed with flight speed.

Domaines: Acoustique [physics.class-ph]; Acoustique [physics.class-ph]

Benoît André, Thomas Castelain, Christophe Bailly, Daniel Juvé. Experimental investigation of screech by an underexpanded supersonic jet with forward flight effect. 10ème Congrès Français d'Acoustique, Apr 2010, Lyon, France. ⟨hal-00550554⟩