Acoustic-Structure Interaction and Air Flow in Violins
These models are featured in the blog post [Analyze Violin Tone and Volume with Multiphysics Modeling](http://www.comsol.com/blogs/analyze-violin-tone-and-volume-with-multiphysics-modeling/). One applies acoustic-structure interaction to study how the air mode resonance is affected by the coupled vibrations in the violin body. The other uses a potential flow approximation to find out how the air ...
Hollow Cylinder
Fluid acoustics coupled to structural objects, such as membranes or plates, represents an important application area in many engineering fields. Some examples are: • Loudspeakers • Acoustic sensors • Nondestructive impedance testing • Medical ultrasound diagnostics This model provides a general demonstration of an acoustic fluid phenomenon in 3D coupled to a solid object. In this ...
Baffled Membrane
Learn how to use the Acoustic-Shell Interaction interface in this tutorial example of a thin vibrating membrane set in an infinite baffle. This example demonstrates how to model the acoustic interaction between a vibrating membrane and the surrounding air. In order to focus on the principles, the geometry is kept simple and the driving mechanism is not modeled.
Gaussian Pulse in 2D Uniform Flow: Convected Wave Equation and Absorbing Layers
This tutorial simulates a standard test and benchmark model for nonreflecting conditions and sponge layers for linearized Euler-like systems. It involves the propagation of a transient Gaussian pulse in a 2D uniform flow. The *Convected Wave Equation, Time Explicit* interface solves the linearized Euler equations with an adiabatic equation of state and the interface uses the Absorbing Layers ...
Organ Pipe Design
The Organ Pipe Designer allows you to study the design of an organ pipe and then play the sound and pitch of the changed design in a user-friendly app. The pipe sound includes the effects of different harmonics with different amplitudes. The organ pipe is modeled using the Pipe Acoustics, Frequency Domain interface in COMSOL Multiphysics. The simulation app allows you to analyze how the first ...
Point Source in 2D Jet: Radiation and Refraction of Sound Waves Through a 2D Shear Layer
This is a benchmark model for the linearized Euler interface of the Acoustics Module. The model is from the NASA "Fourth Computational Aeroacoustics (CAA) Workshop on Benchmark Problems (2004)". The model results are compared to an analytical solution by Agarwal et al. (AIAA Vol. 42, No. 1, January 2004). A point source is located in a narrow 2D jet of Mach 0.8. The model investigates the ...
Acoustic Reflection Analyzer for a Water-Sediment Interface
Analyzing acoustic reflections at surfaces of various structures is important for many engineering disciplines. The Acoustic Reflection Analyzer for a Water-Sediment Interface app shows one such system where the analysis has relevance for underwater acoustics and sonar applications. The app analyzes the reflection and absorption coefficients of plane acoustic waves, scattering off of a water ...
Acoustic Muffler with Thermoviscous Acoustic Impedance Lumping
This model utilizes the thermoviscous acoustic interface in a sub-model to obtain detailed results for the transfer impedance of a perforated plate (including the thermal and viscous losses). The impedance is in turn used as an internal impedance in a pressure acoustic model of a muffler. The results are compared to classic impedance models and measurements.
Vibrations of a Disk Backed by an Air-Filled Cylinder
The vibration modes of a thin or thick circular disc are well known, and it is possible to compute the corresponding eigenfrequencies to arbitrary precision from a series solution. The same is true for the acoustic modes of an air-filled cylinder with perfectly rigid walls. A more interesting question to ask is: What happens if the cylinder is sealed in one end not by a rigid wall but by a thin ...
Axisymmetric Condenser Microphone
This is a model of a condenser microphone with a simple axisymmetric geometry. The model aims to give a precise description of the physical working principles of such a microphone. The condenser microphone is considered to be the microphone with highest quality when performing precise acoustical measurements and with high-fidelity reproduction properties when performing sound recordings. This ...
