Department of Hydrodynamic Systems Project number: 128, 129 Contact person: Dr. György Paál (e-mail: paal@vizgep.bme.hu)
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
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
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
Edge tone results Department of Hydrodynamic Systems
Cavity tone Department of Hydrodynamic Systems