Development and Application of a New Procedure for Fan Noise Prediction

The fan module of the DLR engine noise prediction program PropNoise is introduced in the present paper. By means of analytical models, the program gives a prompt visualization of both aerodynamic and acoustic performances associated with the fan. Single rotating and counter-rotating configurations can be treated. The fan module has two main components: the first is dedicated to the prediction of the steady and unsteady aerodynamic characteristics of the fan, while the second evaluates the noise generation and in-duct propagation. As shown in the paper, this program can be used to calculate performance and acoustic maps for a given fan and allows an acoustic source breakdown at each operating point. Furthermore the acoustic output at the presence of parameter variations provides guidelines for the design-to-noise of fan components. More generally, PropNoise provides helpful insights into the aeroacoustics of fan stages.