TwINJets – Turbulence, Instability and Noise in supersonic twin jets

Jet noise is the primary noise source of aircraft during take-off and landing, and was a key factor in the failure of supersonic transport. Noise-induced loads on aerodynamic elements also affect structural integrity in tactical fighters and launchers.

The main design strategy for jet noise reduction followed since the 50s consisted on increasing the exhaust cross section to achieve the same thrust with lower jet speed. However, this solution has reached a limit, as traditional aircraft architectures do not allow larger engines. New aircraft projects consider diverse possibilities, like tail-mounted engines, Blended Wing-Body architectures, and distributed propulsion systems featuring multiple engines (jet or ducted fans) in close proximity. Most of these configurations present multiple jets in close proximity, which pose a challenge regarding noise suppression.

Project TwINJets aims at a better understanding and modelling of the noise radiated by parallel jets in proximity. Numerical simulations and hydrodynamic instability techniques are combined to (i) shed light on the physics of noise generation and its relation with the large-scale turbulent structures naturally ocurring in the jet flow, including the important interaction between the two jets; (ii) produce accurate but low-cost predictive models of the radiated noise.

“Acción financiada por la Comunidad de Madrid en el marco del Convenio Plurianual con la Universidad Politécnica de Madrid en la línea de actuación estímulo a la investigación de jóvenes doctores”