Instability in Portable Washing Machines

Caty Fairclough | March 30, 2015

Lightweight and portable washing machines are great to use in situations where you do not have access to traditional washing machines. Yet problems may occur when a varied distribution of clothing causes walking instability in these machines. We tested for walking instability during the spin cycle of a portable washing machine and used an active balancing method in an attempt to remove this instability.

Bridget Cunningham | March 6, 2015

Reciprocating engines are used extensively for power generation in a variety of applications, most notably within the automobile industry. In the design process, it is important to ensure that all of the engine’s parts can withstand high stresses and loads in order to maximize the operational lifetime. Here, we analyze fatigue in an engine’s connecting rods.


Mads Herring Jensen | February 25, 2015

When inside a room — a conference room, concert hall, or even a car — everyone has an opinion of when the “acoustics” are good or bad. In room acoustics, we want to study this notion of sound quality in a quantitative way. In short, room acoustics is concerned with assessing the acoustics of enclosed spaces. The Acoustics Module of COMSOL Multiphysics has several tools to simulate the acoustics of rooms and other confined spaces. I will present those here.


Walter Frei | February 19, 2015

A thermostat is a device that senses the temperature of a system and uses this information to control the system’s heaters, or coolers, to keep the temperature close to a desired setpoint. While there are many different types of thermostats, we will focus today on one that turns a heater either on or off based upon two setpoints. This is known as an on-off or a bang-bang controller, and it can be implemented with the Events interface in COMSOL Multiphysics.

Alon Grinenko | January 29, 2015

Acoustic radiation force is an important nonlinear acoustic phenomenon that manifests itself as a nonzero force exerted by acoustic fields on particles. Acoustic radiation is an acoustophoretic phenomenon, that is, the movement of objects by sound. One interesting example of this force in action is the acoustic particle levitation discussed in this previous blog post. Today, we shall examine the nature of this force and show how it can be computed using COMSOL Multiphysics.


Bridget Cunningham | January 15, 2015

The nonuniform distribution of clothes within a washing machine can produce notable vibration and noise. Modeling the dynamics behind this movement and sound can be a valuable tool in optimizing the design of these common household devices.

Bridget Cunningham | February 27, 2015

Truck-mounted cranes are often used for load handling. In many cases, this involves carrying heavy materials, which can exert large forces on various parts of the crane. See how simulation can help identify the impact of these forces and enhance the crane’s operation.

Henrik Sönnerlind | February 23, 2015

We often get requests of the type “I would like to just enter my measured stress-strain curve directly into COMSOL Multiphysics”. In this new blog series, we will take a detailed look at how you can process and interpret material data from tests. We will also explain why it is not a good idea to just enter a simple stress-strain curve as input.

Bridget Cunningham | February 18, 2015

Space frames have been used as the foundation for the construction of many modern buildings, from the Louvre in France to Globen in Sweden. When designing space frames, we need to asses the risk of instability.

Fanny Littmarck | January 22, 2015

Previous work on cloaking for flexural waves in elastic plates presented limitations and near invisibility. Now, a research group in Europe has figured out a new theoretical framework to both overcome the limitations and achieve exact cloaking for flexural waves in Kirchhoff-Love plates. To visualize and test the quality of the cloak, they ran COMSOL Multiphysics simulations.

Ed Gonzalez | January 9, 2015

Nonlinear elastic materials present nonlinear stress-strain relationships even at infinitesimal strains — as opposed to hyperelastic materials, where stress-strain curves become significantly nonlinear at moderate to large strains. Important materials of this class are Ramberg-Osgood for modeling metals and other ductile materials and nonlinear soils models, such as the Duncan-Chang model.

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