# 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.

### Superconducting Wire

Superconducting materials have zero resistivity up to a certain critical current density, above which the resistivity increases rapidly. To model such a material, this model uses a PDE, General Form interface with second-order vector elements. The model was based on a suggestion by Dr. Roberto Brambilla, CESI - Superconductivity Dept., Milano, Italy.

### Eddy Currents

Induced eddy currents and associated thermal loads is of interest in many high power AC applications. This example is of general nature and illustrates some of the involved physics as well as suitable modeling techniques in the AC/DC Module. In this model a metallic plate is placed near a 50 Hz AC conductor. The resulting eddy current distribution in the plate depends on the conductivity and ...

### Multi-turn Coil over an Asymmetric Conductor Plate

This model solves the Testing Electromagnetic Analysis Methods (TEAM) problem 7, “Asymmetrical Conductor with a Hole”—a benchmark problem concerning the calculation of eddy currents and magnetic fields produced when an aluminum conductor is placed asymmetrically above a multi-turn coil carrying a sinusoidally varying current. The simulation results at specified positions in space are ...

### Computing the Resistance of a Wire

Every electrical device has some resistance. That is, when a voltage difference is applied across any two terminals of the device, there will be a directly proportional current flow. This model demonstrates how to compute the resistance of a short section of copper wire. The convergence of the solution with respect to the mesh size is also studied.

### Magnetic Signature of a Submarine

A vessel traveling on the surface or under water gives rise to detectable local disturbances in the Earth’s magnetic field. These disturbances can be used to trigger weapon systems. The magnetic signature of a ship can be reduced by generating a counteracting magnetic field of suitable strength and direction based on prior knowledge of the magnetic properties of the vessel. This model ...

A quadrupole mass filter (QMF) is a key component of a modern mass spectrometer. A QMF uses direct current (DC) and alternating current (AC) electric fields to analyze positive or negative ions by mass to charge ratio. A QMF consists of 4 parallel rods spaced equidistantly, the ratio of the rod radius to the radius of the inscribed circle is 1.148. Opposite pairs of rods are electrically ...

### Inductance and Resistance

This is a model of a simple AC coil: a single-turn thick circular copper wire. A parametric study of current distribution, coil inductance and coil resistance is performed for different frequencies. The skin effect becomes increasingly important at the higher frequencies.

### Electric Machinery in 3D

This is a tutorial how to set up electric machinery in 3D using a combination of the magnetic fields and magnetic fields no currents interfaces.

### Simulating a Generator Made From Nonlinear Materials

This model is a static 3D simulation of a generator having a rotor with permanent magnets. The center of the rotor consists of annealed medium carbon steel, which is a nonlinear ferromagnetic material that is saturated at high magnetic flux densities. The core is surrounded by several blocks of a permanent magnet made of samarium and cobalt, creating a strong magnetic field. The stator is made ...

### RF-Heated Hot Wall Furnace for Semiconductor Processing

Furnace reactors are used in the fabrication of semiconductors to grow layers on wafers. These can also be used for epitaxial growth, which is a key technology for fabrication of electrical devices. A silicon carbide growth takes place in graphite susceptors at very high temperatures (~2000 oC), which are heated with RF coils. The design of the chamber is crucial to reach a uniform ...