Piezoacoustic Transducer
A piezoelectric transducer can be used either to transform an electric current to an acoustic pressure field or, the opposite, to produce an electric current from an acoustic field. These devices are generally useful for applications that require the generation of sound in air and liquids. Examples of such applications include phased array microphones, ultrasound equipment, inkjet droplet ...
Voltage Induced in a Coil by a Moving Magnet
A magnet moving axially through the center of a coil will induce a voltage across the coil terminals. One practical application of this is in shaker flashlights, where the flashlight is vigorously shaken back and forth, causing a magnet to move through a multi-turn coil, which provides charge to the battery. In this model, the motion of a magnet through a coil is modeled, and the induced ...
Red Blood Cell Separation
Dielectrophoresis (DEP) occurs when a force is exerted on a dielectric particle as it is subjected to a nonuniform electric field. DEP has many applications in the field of biomedical devices used for biosensors, diagnostics, particle manipulation and filtration (sorting), particle assembly, and more. The DEP force is sensitive to the size, shape, and dielectric properties of the particles. ...
Capillary Filling - Phase Field Method
This example studies a narrow vertical cylinder placed on top of a reservoir filled with water. Because of wall adhesion and surface tension at the air/water interface, water rises through the channel. Surface tension and wall adhesive forces are often used to transport fluid through microchannels in MEMS devices or to measure, transport and position small amounts of fluid using micropipettes. ...
Acoustic-Structure Interaction
Liquid or gas acoustics coupled to structural objects such as membranes, plates or solids are important applications in many engineering fields. This model is a general demonstration of an acoustic fluid phenomenon in 3D that is coupled to a solid object. The walls of the solid object are impacted by the acoustic pressure. The frequency response from the solid is calculated, which is then fed ...
Free Convection in a Light Bulb
This model treats the free convection of argon gas within a light bulb. It shows the coupling of heat transport (conduction, radiation and convection) to momentum transport (non-isothermal flow) induced by density variations caused by temperature. COMSOL Multiphysics model makes it possible to determine the temperature distribution on the outer surface of the bulb, as well as the temperature ...
Permanent Magnet Motor in 3D
Permanent magnet (PM) motors are used in many high-end applications, such as in electric and hybrid vehicles. An important design limitation is that the magnets are sensitive to high temperatures, which can occur through heat losses caused by currents, particularly eddy currents. In this tutorial, an 18-pole PM motor is modeled in 3D to accurately capture eddy current losses in the magnets. ...
Inkjet
Although initially invented to be used in printers, inkjets have been adopted for other application areas, such as within the life sciences and microelectronics. Simulations can be useful to improve the understanding of the fluid flow and to predict the optimal design of an inkjet for a specific application. The purpose of this application is to adapt the shape and operation of an inkjet nozzle ...
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.
Generator in 2D
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 ...