# Application Gallery

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.

### Rock Fracture Flow

A potential flow model of fluid flow in a rock fracture uses the so-called Reynolds equation. It shows how to use experimental data interpolated to a function used in the equation.

### Thin-Film Resistance

In modeling of transport by diffusion or conduction in thin layers, we often encounter large differences in dimensions of the different domains in a model. If the modeled structure is a so-called sandwich structure, we can replace the thinnest geometrical layers with a thin layer approximation, provided that the difference in thickness is very large. This method can be used in many ...

### Axisymmetric Transient Heat Transfer

This is a benchmark model for an axisymmetric transient thermal analysis. The temperature on the boundaries changes from 0 degrees C to 1000 degrees C at the start of the simulation. The temperature at 190 s from the anlysis is compared with a NAFEMS benchmark solution.

### Joule Heating of a Microactuator

This tutorial model of a two-hot-arm thermal actuator couples three different physics phenomena: electric current conduction, heat conduction with heat generation, and structural stresses and strains due to thermal expansion. In this model version, the geometry is parameterized so that the effect of varying the actuator's dimensions can be analyzed.

### Loaded Spring - Using Global Equations to Satisfy Constraints

Global equations are a way of adding an additional equation to a model. A global equation can be used to describe a load, constraint, material property, or anything else in the model that has a uniquely definable solution. In this example, a structural mechanics model of a spring is augmented by a global equation which solves for the load to achieve a desired spring displacement.

### Diffraction Patterns

This example resembles the well-known 2-slit interference experiment often demonstrated in schools with water waves or sound. This model mimics the plane-wave excitation with two thin waveguides leading to slits in a screen, and it computes the diffraction pattern on the screen’s other side. This diffraction pattern is clearly visible. The main effect of quantization is that the numerical ...

### Convective Cooling of a Busbar

This is a template MPH-file containing the physics interfaces and the parameterized geometry for the model Electrical Heating in a Busbar.