Actuator-generated sound in flow ducts simulated with the CFD solver liner TRACE

Kurzfassung

LinearTRACE is the linearized version of TRACE, the DLR CFD solver for turbomachinery flow problems. Contrary to TRACE which works in the time domain, linearTRACE is a frequency-domain solver. The linearizing offers the possibility to significantly reduce simulation time. The present work studies the ability of linearTRACE to simulate the behavior of actuators aiming at exciting sound in annulus ducts with flow. The actuators are mounted either at the duct wall or on the surface of simplified stator vanes. In both cases the actuators are simulated by harmonically vibrating surfaces. The comparison of the numerical simulations against some analytical solutions validates the excitation of the correct azimuthal and radial mode orders but also indicates that the source type differs from simple monopoles and dipoles in terms of the amplitude ratio of modes propagating upstream and downstream.