1. Department of Hydrodynamic Systems Project number: 128, 129
Contact person: Dr. György Paál (

2. Hybrid method for aeroacoustic simulations
CFX (ANSYS)
Fluid Flow
Flow calculation
Finite-Volume-Method
Time domain
In house code
CFS++
Coupling
Calculation of source terms on fluid mesh
Interpolating source terms onto acoustic mesh
Acoustics
Finite Element Method
Fully Coupled Solution
Time or frequency domain

3. Calculation of the source terms and of the acoustic field
Lighthill’s wave equation:
Where:
After multiplying with a test function w and some derivation, we arrive at the weak formulation of Lighthill's equation:
Department of Hydrodynamic Systems

4. Examples for two well-known aeroacoustic configurations
Edge Tone:
plane free jet – wedge interaction
periodic vortex shedding
dipole sound source
model for outside rear-view mirrors or woodwind instruments (project #128)
Cavity Tone:
flow over a cavity
unstable shear layer
interaction with the downstream edge
complex sound source
e.g. flow over gaps on body of a car or sunroof windo (project #128, 129)
Department of Hydrodynamic Systems

5. Edge tone results
Department of Hydrodynamic Systems

6. Cavity tone
Department of Hydrodynamic Systems