## How to Solve for the Brachistochrone Curve Between Points

##### Chien Liu October 20, 2015

The shortest route between two points isn’t necessarily a straight line. If by shortest route, we mean the route that takes the least amount of time to travel from point A to point B, and the two points are at different elevations, then due to gravity, the shortest route is the brachistochrone curve. In this blog post, we demonstrate how to use built-in mathematical expressions and the Optimization Module in COMSOL Multiphysics to solve for the brachistochrone curve.

Read More##### Caty Fairclough October 19, 2015

When flowing through a constricted area of a pipe, a fluid’s velocity increases and its static pressure decreases. This principle is known as the Venturi effect. Today, we will take a closer look at this effect, including some of its applications.

Read More##### Caty Fairclough October 15, 2015

On the last day of the COMSOL Conference 2015 Boston, attendees gathered together to celebrate the recipients of the Best Paper and Poster awards. The awards were given to winners with projects covering many different subject areas, ranging from food science and electronic devices to plasma research and IED detection. Here, we’ll share more information about their innovative work.

Read More##### Fabio Bocchi October 14, 2015

As a technical support engineer, one of the most common technical questions I receive is: “How can I compute the mass conservation of a fluid flow simulation or the energy balance of a conjugate heat transfer simulation?” This is often requested to investigate and ensure a simulation’s accuracy. Here, I will demonstrate how to perform these calculations in COMSOL Multiphysics and introduce some of the predefined variables available for postprocessing the energy rate terms of the energy balance equation.

Read More##### Alon Grinenko October 13, 2015

In our Acoustophoretic Force blog series, we have discussed the nature of acoustic radiation force and different ways to compute this force in the COMSOL MultiphysicsÂ® software. Today, we will introduce you to a related phenomenon, acoustic orbital angular momentum, and demonstrate how to model it.

Read More##### Bridget Cunningham October 12, 2015

Arteries are designed to carry blood containing oxygen and nutrients from the heart to other areas of the body. Studying this biological soft tissue from a mechanical standpoint requires a reliable model that can fully describe the arteries’ anisotropic nonlinear response. Our tutorial of arterial wall mechanics illustrates such a design.

Read More##### Chandan Kumar October 8, 2015

MEMS resonators are microelectromechanical systems primarily used as sensor elements, filters, and frequency elements. Two common actuation methods for MEMS resonators are piezoelectric actuation and electrostatic actuation. In this blog post, we will discuss the modeling of electrostatically actuated MEMS resonators. When modeling such resonators, you will often come across terms such as equilibrium point, pull-in, pull-in voltage, and time harmonic response of a biased resonator. We will explain these phenomena using a simple representation of an actuator.

Read More##### Brianne Costa October 7, 2015

While the offshore oil industry is usually very profitable, it can also be unpredictable, and at times, dangerous. Corrosion in steel oil platforms can lead to damage and failure of the structure, loss of business, and even on-site accidents. Fortunately, there are various ways to investigate and prevent corrosion in these structures to ensure a safe and productive drilling operation.

Read More##### Nirmal Paudel October 6, 2015

The Rotating Machinery, Magnetic physics interface available in the AC/DC Module is used to model rotating machines such as motors or generators. When modeling the linear or tubular device with the Magnetic Fields and the Moving Mesh physics interfaces, it is appropriate to use a customized linear periodic boundary condition. In this blog post, we will explore how to customize the linear periodic boundary condition and model the tubular generator that is used for wave energy.

Read More##### Temesgen Kindo October 5, 2015

Previously on the blog, we introduced you to Linear Extrusion operators and demonstrated their use in mapping variables between a source and a destination. This approach, as explained earlier, is limited to cases in which the source and destination are related by affine transformations. Today, we will discuss General Extrusion operators, which are designed to handle nonlinear mappings and the mapping of variables between geometric entities of different dimensions.

Read More##### Bridget Cunningham October 2, 2015

Over the years, energy harvesting has become a popular approach to power small wireless devices. For energy harvesters to yield optimal results, it is important that their design configurations maximize the level of power transfer. Here, we will explore the role of simulation in advancing the design of a piezoelectric energy harvester.

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