# Application Gallery

The Application Gallery features COMSOL Multiphysics tutorial and demo app files pertinent to the electrical, mechanical, fluid, and chemical disciplines. You can download ready-to-use tutorial models and demo apps with step-by-step instructions for how to create them yourself. The examples in the gallery serve as a great starting point for your own simulation work.

Use the Quick Search to find tutorials and apps relevant to your area of expertise. Log in or create a COMSOL Access account that is associated with a valid COMSOL license to download the MPH-files.

### Stresses and Strains in a Wrench

This tutorial demonstrates how to set up a simple static structural analysis. The analysis is exemplified on a combination wrench during the application of torque on a bolt. Despite its simplicity, and the fact that very few engineers would run a structural analysis before trying to turn a bolt, the example provides an excellent example of structural analysis in COMSOL Multiphysics.

### Free Convection in a Water Glass

This model treats the free convection and heat transfer of a glass of cold water heated to room temperature. Initially, the glass and the water are at 5 °C and are then put on a table in a room at 25 °C. The nonisothermal flow is coupled to heat transfer using the Heat Transfer module.

### Evaporative Cooling of Water

This tutorial shows how to couple three physics interfaces to model evaporative cooling. The effects need to be taken into account are heat transfer, transport of water vapor and fluid flow. User-defined expressions are used to implement the source term for the water vapor and evaporative heat source, as well as the moist air feature to accurately describe the material properties.

### 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.

### Optical Scattering by Gold Nanospheres

This model demonstrates the simulation of the scattering of a plane wave of light by a gold nanosphere. The scattering is computed for the optical frequency range over which gold can be modeled as a material with negative complex-valued permittivity. The far-field pattern and losses are computed.

### E-Core Transformer

This is the transient model of a single phase E-core transformer using a Multi-Turn Coil Domain. The model includes the effect of a nonlinear B-H curve in the core and shows how to connect the transformer model to the external circuits using Electric Circuit interface. The simulation is performed for two different cases; the first one with a unity turn ratio and second one with a turn ratio of ...

### Flow Through a Pipe Elbow

Water flow in a 90 degree pipe elbow. The flow is simulated using the k-omega turbulence model. The result is compared to engineering correlations.

### Computing Capacitance

A capacitor, in its simplest form, is a two terminal electrical device that stores electric energy when a voltage difference is applied across the terminals. The stored electric energy is proportional to the applied voltage squared and is quantified by the capacitance of the device. This model introduces a model of a simple capacitor, the electric field and device capacitance are solved for ...

### Frequency Selective Surface, Periodic Complementary Split Ring Resonator

Frequency selective surfaces (FSS) are periodic structures with a bandpass or a bandstop frequency response. This model shows that only signals around the center frequency can pass through the periodic complimentary split ring resonator layer.

### Magnetic Field of a Helmholtz Coil

A Helmholtz coil is a parallel pair of identical circular coils spaced one radius apart and wound so that the current flows through both coils in the same direction. This winding results in a uniform magnetic field between the coils with the primary component parallel to the axes of the two coils. Applications of Helmholtz coils range from canceling the earth’s magnetic field to generating ...