Technology of prediction acoustic disturbances in flow far field in rotating framework

The paper is dedicated to application of the Ffowks–Williams–Hawkings method for prediction of acoustical pulsations in the far field in the case when computations in the near field are performed in the rotating coordinate system. Such formulation is convenient, in particular, for numerical simulation of a single rotor. If the speed of rotation is high enough then in the classiccal «1А» Farassat formulation with the control surface connected to the mesh there arise singularities in the expression under the intergal sign. To avoid this problem we use an axialsymmetric control surface which is assumed to be unmoving in the absolute coordinate system. This allows us to reduce additional difficulties arising due to rotation to interpolation and calculating derivatives with respect to the angle.