Fan wake modelling for computational aeroacoustic simulations of turbulence-cascade interaction noise

The present work addresses the numerical modelling of fan wakes using synthetic turbulence and its influence on turbulence-cascade interaction noise predictions. Initial results show that cascade noise only depends on the circumferentially-averaged turbulence spectra that interact with the cascade. Consequently, isotropic turbulence produces noise predictions with approximately the same level of accuracy than fan wakes with cyclostationary variations in both turbulent kinetic energy and integral length scale. The paper also includes a parameter study on the effects of vane count and camber on cascade noise from thick aerofoils. Numerical results show that vane count may have a significant effect on noise predictions at low frequencies, whereas the effects of camber are negligible.

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