Galleria dei Modelli
Acoustic Muffler with Thermoacoustic Impedance Lumping
This model utilizes the thermoacoustic interface in a submodel to obtain a detailed (and more precise) measure for the transfer impedance of a perforated plate. The impedance is in turn used as an internal impedance in a pressure acoustic model of a muffler. Results are compared to classic impedance models.
Vibrating Particle in Water: Correct Thermoacoustic Material Parameters
This is a tutorial model that simulates a small vibrating hemispherical particle in water. The vibrations induce acoustic waves in the fluid. The model shows how to set up the material parameters in a thermoacoustic model to get the correct acoustic (compressible) waves in the fluid.
Doppler Shift
We have all noticed the Doppler effect when an ambulance passes by with its sirens blaring. The siren’s pitch suddenly drops the moment the ambulance starts moving away from you. Another effect you can notice is how the siren’s sound is very loud when nearby, but as soon as the ambulance has passed the sound becomes much quieter. This model simulates the acoustic Doppler effect by ...
Absorptive Muffler with Shells
This model describes the pressure wave propagation in a muffler for an internal combustion engine. The purpose of the model is to show how to analyze both inductive and resistive damping in pressure acoustics as well as coupling the fluid to the surrounding elastic shell structure of the muffler. Finally, the eigenmodes of a pure structural problem is analyzed and the modes compared to peaks in ...
Jet Pipe
This example models the radiation of fan noise from the annular duct of a turbofan aeroengine. When the jet stream exits the duct, a vortex sheet appears along the extension of the duct wall due to the surrounding air moving at a lower speed. The near field on both sides of the vortex sheet is calculated. The Aeroacoustics modeling interface in the Acoustics Module describes acoustic waves in a ...
Bessel Panel
The Bessel panel is a way to arrange a number of loudspeakers so that the angular sound distribution resembles that of a single speaker. This model combines five Bessel panels in the same pattern to approximate a purely radial sound field. The speakers are driven with different signals, some of them in counter-phase. This results in an approximately homogeneous polar far-field ...
Eigenmodes in a Muffler
In this model, compute the propagating modes in the chamber of an automotive muffler. The geometry is a cross-section of the chamber in the Absorptive Muffler example. The model’s purpose is to study the shape of the propagating modes and to find their cut-off frequencies. As discussed in the documentation for the Absorptive Muffler, some of the modes significantly affect the damping of the ...
Loudspeaker Suspension
In this model, the resistance and compliance of the suspension in the Loudspeaker Driver model are computed using a purely mechanical analysis.
