High-fidelity flow and noise simulations of double-stream jet installed in T-tail configuration

The aerodynamic field and the acoustic signature of a mixed-stream cold coaxial jet, representative of a low-bypass ratio engine and installed on a T-tail configuration typical of business jets is investigated numerically. The nozzle diameter is 80 mm and the jet velocity is 280 m/s (M=0.9) for both streams, leading to a Reynolds number R e D = 1 . 5 × 1 0 6 . The time-accurate flow fields are simulated with the Wall Modelled LES branch of the hybrid RANS/LES approach ZDES, namely ZDES mode 3, and are used to reconstruct radiated noise with the Ffowcs Williams and Hawkings integral formulation. The full T-tail region is included in the aerodynamic simulation to account for scattering effects. A very good match with the experimental flow and noise data is found but the important numerical dissipation that occurs during the propagation of the sound waves towards the tailplane restricts the prediction to low- and medium-frequencies in this direction. The jet is found to be far enough from the fuselage and horizontal tailplane not to be impacted by their presence; this property is used to model the acoustic radiation towards the tailplane from an isolated jet configuration that matches the wall pressure levels and spatial coherence up to the high frequencies. • Near- and far-field jet noise is predicted for a nozzle installed on a business jet. • Noise sources are computed and propagated to the T-tail with high-fidelity simulation. • The fuselage does not impact noise sources, identical to those of an isolated jet. • Acoustic signature on the T-tail can be modelled from the isolated jet simulation.