Abstract:
An analysis of the possibility of applying a method developed by the author's zone
RANS-IDDES method, which includes a scheme with a local imposition of implicit to
the problem of calculating the noise of the turbofan engine fan. The estimates of the required mesh power are presented to use the Wall Modeled LES on the 1/4 chord of the
rotor blades near their rear edges, which made more than 600M cells. It was concluded
that the impossibility of consideration of the flow in a vortex-solving formulation for
border layers on the rotor blades from their front edges for current and promising calculations. The calculation confirmed already published ideas that the zonal RANS-LES approach to the vortex resolved with the explicit and high-quality generation of turbulent
content is preferable for such tasks. The importance of the qualitative description within
the URANS regions near the front edges of the rotor blades, especially near the radial
gap, is noted. A modification of a VSTG generator is proposed, which improves the size
of the generation for the nonuniform mean field of speeds. As a result, the noise of the
fan stage is obtained, which is consistent with the exploiter, both in tonal and in broadband parts.
Keywords:aeroacoustics, fan stage noise, embedded LES, synthetic turbulence generator
with volume source.
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