The Application Gallery features COMSOL Multiphysics® tutorial and demo app files pertinent to the electrical, structural, acoustics, fluid, heat, and chemical disciplines. You can use these examples as a starting point for your own simulation work by downloading the tutorial model or demo app file and its accompanying instructions.

Search for tutorials and apps relevant to your area of expertise via the Quick Search feature. To download the MPH-files, log in or create a COMSOL Access account that is associated with a valid COMSOL license. Note that many of the examples featured here can also be accessed via the Application Libraries that are built into the COMSOL Multiphysics® software and available from the File menu.

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COMSOL News Magazine 2017

Vibrating Plate in a 2D Viscous Parallel Plate Flow

This is a small 2D demonstration model that couples the *Linearized Navier-Stokes, Frequency Domain*, *Solid Mechanics*, and *Creeping Flow* physics interfaces to model the vibrations of a plate located in a 2D viscous parallel plate flow. This type of model is used to model fluid-structure interaction (FSI) in the frequency domain. For simplicity, the flow is assumed to be a creeping flow. ...

Nonlinear Slit Resonator: Coupling Acoustics and CFD

In many applications, acoustic waves interact with surfaces that have small perforations or slits. This can be in muffler systems; in soundproofing structures; in liners for noise suppression in jet engines; or in grilles and meshes in front of, for example, miniature speakers in mobile devices. At medium to high sound pressure levels, the local particle velocity in the narrow region of the ...

Shape Optimization of a Tweeter Waveguide

This application illustrates how to use COMSOL’s optimization capabilities to automatically develop novel designs satisfying critical design constraints. The model optimizes a simple speaker geometry. Examples of constraints could include the radius of the loudspeaker or a desired minimum achievable sound-pressure level. To exemplify the optimization capabilities this application studies 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 ...

Muffler with Perforates

Reflective mufflers are best suited for the low-frequency range where only plane waves can propagate in the system, while dissipative mufflers with fibers are efficient in the mid- to high-frequency range. Dissipative mufflers based on flow losses, on the other hand, also work at low frequencies. A typical automotive exhaust system is a hybrid construction consisting of a combination of ...

Acoustics of a Pipe System with 3D Bend and Junction

This tutorial shows how to model the propagation of acoustic waves in large pipe systems by coupling the *Pipe Acoustics* interface to the *Pressure Acoustics* interface. The tutorial is set up in both the time domain and the frequency domain. 1D pipe acoustics is used to model the propagation in the long straight pipe portions. A 3D model of a pipe junction and pipe bend is coupled to the 1D ...

Gaussian Pulse Absorption by Perfectly Matched Layers: Pressure Acoustics, Transient

This tutorial simulates a standard test and benchmark model for perfectly matched layers (PMLs) as absorbing boundary conditions in the time domain. It involves the propagation of a transient Gaussian pulse with no flow. The _Pressure Acoustics, Transient_ interface is used together with PMLs to reduce the computational domain and suppress the reflections from the artificial boundaries. An ...

Photoacoustic Resonator

This is a model of a simple photoacoustic (or optoacoustic) resonator. A pulsating laser heats a gas causing expansion and contraction and thus creates pressure waves. Such devices are used as sensors for measuring material parameters of the gas inside the resonator. The resonance frequency of the system depends on the gas in the resonator. The model uses the Thermoviscous Acoustic, Frequency ...

Optimizing the Shape of a Horn

A plane-wave mode feeds an axisymmetric horn radiating from an infinite baffle towards an open half space. The radius of the feeding waveguide is assumed to be fixed, as well as the depth of the horn and the size of the hole where the horn is attached to the baffle. By varying the curvature of the initially conical surface of the horn, its directivity and impedance can be changed. This model ...

One-Family House Acoustics

This model shows an application of the Acoustic Diffusion Equation physics interface. The acoustics in a two story one-family house consisting of 10 rooms is analyzed. The steady state sound pressure level (acoustic energy density) distribution is analyzed for a sound source located in the main living room. The reverberation time T60 of the different coupled rooms is then studied using the ...