# Model Gallery

The Model Gallery features COMSOL Multiphysics model files from a wide variety of application areas including the electrical, mechanical, fluid, and chemical disciplines. You can download ready-to-use models and step-by-step instructions for building the model, and use these as a starting point for your own modeling work. Use the Quick Search to find models relevant to your area of expertise, and login or create a COMSOL Access account that is associated with a valid COMSOL license to download the model files.

### Assembly with a Hinge - new

In mechanical assemblies, parts are sometimes connected so that they are free to move relative to each other in one or more degrees of freedom. Examples of such connections are ball joints, hinges, and different types of bearings. If the details of the connection are not the subjects of the analysis, it is often possible to model the connection using the Rigid Connector feature in COMSOL ...

### 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 ...

### Two-port Piezoelectric SAW Device - new

This tutorial shows how to model surface acoustic waves in time domain. The 3D modeling geometry represents a 128 degree YX-cut lithium niobate substrate. The SAW device has two ports. The metallic electrodes are modeled as perfect conductors using boundary conditions. The geometric dimensions such as size of substrate, the gap between the ports and the number of inter-digitated electrodes (IDTs) ...

### Critical Frequencies for a Rotor

The rotor in an electric motor is analyzed. In the design of a motor it is important that no eigenfrequencies for the rotor lie within the operating interval of the revolution speed (in revolutions / second) for the motor. If the eigenfrequencies of the rotor lie in this interval then this shortens the engines lifetime, and can sometimes even lead to dysfunction and breakdown. This 3d model of ...

This model is compared to a NAFEMS benchmark for composite material modeling, No R0031/2. The geometry is a long, thick, and hollow cylinder consisting of two layers, where an internal pressure is applied. The inner layer is made from an isotropic material, while the outer layer is made from an orthotropic material. This material's properties are equal in the radial and axial directions, yet ...

### Thermal Drift in a Microwave Filter Cavity - new

Microwave filters are used to eliminate unwanted frequency components in the output from microwave transmitters. They are typically inserted between a power amplifier and an antenna. The amplifiers are nonlinear and produce harmonics that must be eliminated with filters that have a rather narrow passband. Due to high power loads but also possibly from harsh environmental conditions (such as a ...

### Thick Wall Cylinder Benchmark Problem

A thick wall cylinder is exposed to both internal and external pressure and thermal load. The model is both plane and axisymmetric. The results are compared to the analytic solution.

### Stress Analysis of an Elliptic Membrane - new

This is a benchmark model for a plane stress problem. The accuracy of the computed stress concentration is evaluated, and a mesh convergence study is performed for different element types.

### Shift into gear

This model demonstrates the ability to simulate Multibody Dynamics in COMSOL. It comprises a multilink mechanism that is used in an antique automobile as a gearshift lever. It was created out of curiosity to find out how large forces are on the individual components. The model uses flexible parts, i.e. the Structural Mechanics Module was used along with the Multibody Dynamics Module.

### Connecting Shells and Beams - new

Many engineering structures consist of thin and slender components, where a full solid model will result in extremely many small elements. For such structures, it is much more efficient to use shell or beam elements. In this tutorial and verification model, it is shown how to connect beam and shell elements in different situations. The results are also compared to a solid model of the same ...