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.

Porous Reactor with Injection Needle

This model treats the flow field and species distribution in an experimental reactor for studies of heterogeneous catalysis. The model exemplifies the coupling of free and porous media flow in fixed bed reactors. The reactor consists of a tubular structure with an injection tube that has its main axis perpendicular to the axis of the reactor. The incoming species in the main and injection ...

Phase Change

This example demonstrates how to model a phase change and predict its impact on a heat transfer analysis. When a material changes phase, for instance from solid to liquid, energy is added to the solid. Instead of creating a temperature rise, the energy alters the material’s molecular structure. Equations for the latent heat of phase changes appear in many texts but their implementation is ...

Two-Phase Flow in Porous Media

The first model describes the simultaneous flow of two immiscible fluids in porous media - here air displaces water in a multi-step inlet pressure experiment. We solve for the pressure and the degree saturation for the air and water within a representative volume and so track saturation levels rather than estimating a discrete location for the air-water interface. A second example is also ...

Computing Q-Factors and Resonant Frequencies of Cavity Resonators

A classic benchmark example in computational electromagnetics is to find the resonant frequency and Q-factor of a cavity with lossy walls. Here, models of rectangular, cylindrical, and spherical cavities are shown to be in agreement with analytic solutions.

Airflow Over an Ahmed Body

The Ahmed body represents a simplified, ground vehicle geometry of a bluff body type. Its shape is simple enough to allow for accurate flow simulation but retains some important practical features relevant to automobile bodies. This model describes how to calculate the turbulent flow field around a simple car-like geometry using the Turbulent Flow, k-epsilon interface. Detailed instructions ...

Laminar Flow in a Baffled Stirred Mixer

This model exemplifies the use of the Rotating Machinery interface, which allows you to model moving rotating parts in, for example, stirred tanks, mixers, and pumps. The Rotating Machinery interface formulates the Navier-Stokes equations in a rotating coordinate system. Parts that are not rotated are expressed in the fixed material coordinate system. The rotating and fixed parts need to be ...

Forced and Natural Convection Cooling of Circuit Boards

The suite of models examine the air cooling of circuit boards populated with multiple integrated circuits (ICs), which act as heat sources. Two possible cooling scenarios are depicted: vertically aligned boards using natural convection, and horizontal boards with forced convection (fan cooling). In this case, contributions caused by the induced (forced) flow of air dominate the cooling. To ...

Simulating the Moving Parts of a Generator

In this model, a rotor with permanent magnets and a nonlinear magnetic material rotates within a stator of the same magnetic material. The generated voltage in windings around the stator is calculated as a function of time. COMSOL Multiphysics models the rotation with assemblies and identity pairs. The nonlinearity of the magnetic material is also taken into account using an interpolation ...

DC Characteristics of a MOS Transistor (MOSFET)

This model calculates the DC characteristics of a simple MOSFET. The drain current versus gate voltage characteristics are first computed in order to determine the threshold voltage for the device. Then the drain current vs drain voltage characteristics are computed for several gate voltages. The linear and saturation regions for the device can be identified from these plots.

Modeling a Dipole Antenna

The dipole antenna is one of the most straightforward antenna configurations. It can be realized with two thin metallic rods that have a sinusoidal voltage difference applied between them. The length of the rods is chosen such that they are quarter wavelength elements at the operating frequency. Such an antenna has a well known torus-like radiation pattern.

Quick Search