As turbofan engine designs move towards very high bypass ratios and corresponding low pressure ratios, fan rotor blade tip Mach numbers are reduced, leading to rotor-stator interaction being an important contributor to tonal fan noise. For future aircraft configurations employing boundary layer ingestion, non-uniform ow enters the fan. The impact of such non-uniform ows on the generation and propagation of rotor-stator interaction tones has yet to be assessed. In this paper, a novel approach is proposed to numerically predict the generation and propagation of rotor-stator interaction noise with distorted in ow. The ultimate goal is to employ the approach to assess the impact of inlet ow distortion on the downstream propagating sound power. Traditional approaches to numerically predict rotor-stator interaction tones require a sliding interface between the rotor and stator which may distort rotor wakes and can cause non-physical acoustic wave re ections if time steps are not su ciently small. Further, in non-uniform ow, full-annulus computations are required to capture the periodicity of the ow and acoustic fields. To avoid potential issues associated with sliding interfaces and to lower computational costs, the rotor is modeled using body forces. The model responds to local ow conditions and thus can capture the e ects of ow distortions with wavelengths significantly larger than the blade pitch. Since rotor-stator interaction noise is generated by the incidence of the rotor wakes onto the stator vanes, the key challenge in this approach is to produce the wakes using a body force representation of the rotor. It is shown that such an approach can produce wakes by concentrating the viscous forces along each circumferential streamtube in the last 15% chord. The viscous force is applied over a circumferential extent approximately equivalent to the sum of the blade trailing edge pressure and suction surface boundary layer thicknesses. The new approach to rotor wake generation is assessed on the GE R4 fan from NASA's Source Diagnostic Test, for which the computed overall aerodynamic performance matches the experiment to within one percent. The individual rotor blade wakes are generated with widths in excellent agreement and depths in fair agreement with the experiment. A preliminary acoustic assessment using modal sound power levels computed in the exhaust duct indicates that the approach shows promise for predicting downstream propagating rotorstator interaction noise. The next steps involve finalizing the assessment of the approach for uniform in ow and the approach to assess the impact of inlet distortion on rotor-stator interaction noise generation and propagation.