As the degree of bypass ratio of modern aviation turbofan engines increases, their appearance and characteristics change as well: the nacelle diameter increases, the air intake length decreases, and the temperature and jet noise reduce. Due to these circumstances, the design must take into account the interaction between the fan and the air intake as part of configuration. An approach based on unsteady three-dimensional modeling with account for full blade tips is necessary for the analysis, but is resource-intensive. In some cases, an approach based on the “actuator disk” boundary condition can be used to study aerodynamic interference. The paper considers a validated computational technique based on the “actuator disk” boundary condition with flow structure in front of the fan taken into account. The results of the computational study of the characteristics of the fan model in the engine nacelle are given, as well as the analysis of options for the “actuator disk” boundary condition and their application to the calculation of a non-uniform flow in the air intake under side wind conditions.