# 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.

### Stress Analysis of an Elliptic Membrane

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.

### Isospectral Drums

Striking a drum excites a spectrum of vibration modes that together make up the instrument’s characteristic sound or acoustic signal. These vibration modes correspond to the eigenmodes, or eigenfunctions, of the drum’s membrane. Thus you can study this problem by solving eigenvalue problems for stretched membranes. Two different geometric shapes are modeled, with all other parameters ...

### The Blasius Boundary Layer

The incompressible boundary layer on a flat plate in the absence of a pressure gradient is usually referred to as the Blasius boundary layer. The steady, laminar boundary layer developing downstream of the leading edge eventually becomes unstable to Tollmien-Schlichting waves and finally transitions to a fully turbulent boundary layer. Due to its fundamental importance, this type of flow has ...

### Electric Heating in a Busbar, Modeled with LiveLink for Solid Edge

This tutorial model of the Joule heating effect in a busbar demonstrates how to synchronize an assembly between Solid Edge and COMSOL, how to modify the geometry from COMSOL, and how to run a geometric parametric sweep.

### Reactive Muffler

This is a benchmarking model to compare the abilities of COMSOL to an analytical solution. The model examines the sound-transmission properties of an idealized reactive muffler with infinitely long inlet and outlet pipes and one expansion chamber. The infinitely long inlet and outlets are simulated through a reflection-free source at the inlet pipe and a reflection-free end of the outlet pipe, ...

### AC Electrokinetically Enhanced Surface Reactions

This model studies the use of AC electrokinetic forces to enhance the rate of transport of electrolytic reactants to a reaction surface on the wall of a microchannel. If transport was to be governed by flow alone, then the flow velocity perpendicular to the surface would be so small that the analyte would be transported mainly by diffusion. The reaction rate at the surface is large enough ...

### Circular Waveguide Iris Bandpass Filter

A circular waveguide filter is designed using a 2D axisymmetric model. Six annular rings added to the waveguide form circular cavities connected in series, and each cavity cutoff frequency is close to the center frequency of the filter. The simulated S-parameters show a bandpass frequency response.

### Optimization of a Tuning Fork, Modeled with LiveLink for Solid Edge

This model computes the fundamental eigenfrequency and eigenmode for a tuning fork that is synchronized from Solid Edge via the LiveLink interface. The length of the fork is then optimized so that the tuning fork sounds the note A, 440 Hz.

### Transport and Reaction in a Catalyst in 3D

Consider the study of a mass balance of a diluted species in air, for example, a pollutant in an exhaust stream. The model’s aim is to calculate the concentration profile of this species, which is decomposed by a catalyst present on the surface of a porous supporting structure. In a first step, you solve the velocity field for the solution assuming that the diluted pollutant has no influence ...

### Caughey-Thomas Mobility in a Semiconductor

With an increase in the parallel component of the applied field, carriers can gain energies above the ambient thermal energy and be able to transfer energy gained by the field to the lattice by optical phonon emission. The latter effect leads to a saturation of the carriers mobility. The Caughey Thomas mobility model adds high field velocity scattering to an existing mobility model (or to a ...