A simplified method is proposed to model analytically the tonal noise generated by the impingement of rotor wakes on the outlet guide vanes (OGV) of a low-speed axial-flow fan. Equivalent dipoles are placed very close to the OGV leading edges. It is shown that the loading induced on the vanes by such edge-dipoles is similar to their unsteady aerodynamic response according to a classical thin-airfoil theory. Tuning coefficients are determined to cover a large range of parameters. The scattering of each dipole is calculated with a mode-matching technique which takes into account the cascade effect of the stator. This approach is then used to model a heterogeneous stator configuration. Comparisons with a modal decomposition obtained from a fan experimental data base are performed.
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