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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Helmholtz Resonator with Flow: Interaction of Flow and Acoustics

Helmholtz resonators are used in exhaust systems, as they can attenuate a specific narrow frequency band. The presence of a flow in the system alters the acoustic properties of the resonator and the transmission loss of the subsystem. In this tutorial model, a Helmholtz resonator is located as a side branch to a main duct. The transmission loss through the main duct is investigated when a flow ...

Radially Polarized Piezoelectric Transducer

This tutorial model shows how a user-defined coordinate system can be used to create any type of directional polarization of a piezoelectric material. Results are shown for the case of radial polarization of a piezoelectric disk. The piezoelectric material is PZT-5H. The example shows a static analysis. Visualization of the cylindrical coordinate system as well as the stress/strain in that ...

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.

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. ...

Vibrating Micromirror with Viscous and Thermal Damping

Micromirrors are used in certain MEMS devices to control optic elements. This model of a vibrating micromirror surrounded by air uses the Thermoacoustic-Shell Interaction user interface to model the fluid-solid interaction, and it thus includes the correct viscous and thermal damping of the mirror from the surrounding air. The resonance frequency of the mirror when under a torquing load is ...

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 ...

Ultrasonic Flow Meter with Piezoelectric Transducers: Coupling between FEM and DG

Ultrasonic flow meters determine the velocity of a fluid flowing through a pipe by sending an ultrasonic signal across the flow at a skew angle. When there is no flow, the transmitting time between the transmitter and the receiver is the same for the signals sent in the upstream and downstream directions. Otherwise, the wave traveling downstream moves faster than the one traveling upstream, ...

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 ...

Nonlinear Acoustics — Modeling of the 1D Westervelt Equation

This model example shows how to model nonlinear propagation of 1D finite-amplitude Acoustic waves in fluids using Acoustics Module of COMSOL Multiphysics. The model is based on the 2nd order Westervelt equation. The one dimensional nonlinear wave equation is solved in the time domain by adding the nonlinear term to the linear equation. The model does not include energy dissipation in order to ...

Generic 711 Coupler—An Occluded Ear-Canal Simulator

This is the model of an occluded ear canal simulator (a generic 711 coupler). Besides certain details the geometry corresponds to the Brüel & Kjær Ear Simulator Type 4157. The real life couplers are used for simulating the acoustics of a standardized human ear canal and can be used for measurements on all sorts of devices. They are widely used in the hearing aid industry but also as ear ...