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.


Submarine Scattering: Time-Domain Simulation and FFT

This model analyzes the scattering of a plane wave off a submarine hull. The scattered field and the spatial response are also determined. The model uses the *Pressure Acoustics, Time Explicit* interface to model this large acoustic model in the time domain. Then, a *Time to Frequency FFT* study is used to transform the results into the frequency domain and the scattered field is analyzed with ...

Acoustic Cloaking

Two articles in the New Journal of Physics describe how to derive necessary conditions on an anisotropic density tensor to create a perfect acoustic cloak in 2D, and show how this material can be realized in practice as a layered shell with isotropic properties in each layer. These two example files illustrate simplest possible implementations using both anisotropic density and the layered ...

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 ...

Multilayered Porous Material: Poroelastic Waves with Thermal and Viscous Losses (Biot-Allard Model)

In applications where pressure and elastic waves propagate in porous materials filled with air, both thermal and viscous losses are important. This is typically the case in insulation materials for rooms, lining materials in car cabins, or foams used in headsets and speakers. Another example is porous material in mufflers in the automotive industry. In many cases, these materials can be modeled ...

Lumped Loudspeaker Driver

This is a model of a moving-coil loudspeaker where a lumped parameter analogy represents the behavior of the electrical and mechanical speaker components. The Thiele-Small parameters (small-signal parameters) serve as input to the lumped model, which is represented by an Electric Circuit physics. The lumped model is coupled to a 2D axisymmetric Pressure Acoustics model describing the ...

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 ...

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. ...

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 ...

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 ...

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 ...