Computational Fluid Dynamics (CFD) Blog Posts
Fluid-Structure Interaction (FSI) using COMSOL Multiphysics
Today we have the pleasure of welcoming Nagi Elabbasi of Veryst Engineering as a guest blogger. Read on to see what this COMSOL Certified Consultant has to say about fluid-structure interaction. Two weeks ago I led a webinar on fluid-structure interaction (FSI) using COMSOL Multiphysics. FSI involves coupling between a deformable or moving structure and a surrounding or internal fluid flow. There is a growing number of engineering and scientific problems where a purely structural or purely CFD analysis just […]
Skimboard Hydrodynamics: It’s All in the Boundary Conditions
When it comes to recreational water sports, simulation can make a dramatic difference in performance. Skimboards are a perfect example of this. These short, thin boards are similar to surfboards without fins and they allow riders to float on the water’s surface and glide. In order to improve the design of the board, one group of researchers relied on hydrodynamics to understand the interaction between water and skimboards.
Modeling Flow: Heat Exchanger Microchannels
Plate heat exchangers have a larger surface with respect to their volume as compared to a conventional shell and tube design, making for an efficient temperature regulation device. As the name infers, these types of heat exchangers consist of layers of corrugated metal forming channels in between. In order to optimize their performance, you need the flow through the channels to be well-distributed. As you can imagine, the flow is very detailed and modeling it can be computationally demanding, if […]
Efficient Solar Panel Design Improves the PV Industry
Solar photovoltaic (PV) cells are semiconductor devices that directly convert solar energy into electricity or voltage using the photovoltaic effect. These PV cells are more commonly known as solar cells, or solar panels, and in 2012 they produced roughly 93 terawatt-hours (TWh) of electricity — enough energy to power over 20 million homes. Because the cells must be directly exposed to the sun’s rays, they are housed outdoors where the panels are affected by the elements. Therefore, the cells must […]
Inertial Focusing, a Counterintuitive Approach to Concentrate Cells
Suppose we have a rectangular microchannel containing a laminar flow with Reynolds number Re = 1. Next, let’s randomly distribute suspended particles at the channel’s inlet. Given that there are no external forces acting on these particles, you would intuitively expect that the particles would trace the fluid streamline. However, scientists from Massachusetts General Hospital (MGH) and Veryst Engineering would disagree, and their research findings suggest a completely different pattern than what would be expected. The researchers claim that depending […]
The Physics of Sailing, a CFD Analysis
Of all boats, I find sailboats to be the most fascinating, especially when sails are their only means of propulsion. Kinetic energy is transferred from the wind to the sails, which results in a lift force that balances drag forces and allows the sailboat to move through the water. We are all familiar with the parts of a boat above the waterline: deck, spars, sails, and the rudder used to turn the boat (figure 1c). Not everyone pays attention to […]
CFD Applied to Two-Phase Flow, an Italian Dressing Simulation
The fact that oil and water don’t mix is something that you are probably all familiar with. At one point or another, you’ve most likely noticed what happens when you shake a bottle of say, Italian salad dressing, and the liquids mix momentarily, only to become separated again within seconds as oil bubbles rise to the surface. Creating a simulation describing how these two immiscible fluids interact is a great way to introduce computational fluid dynamics (CFD) applied to two-phase […]
Non-Newtonian Fluids: The Pouring Ketchup Quandary
If you enjoy ketchup with your food, there’s a good chance you’ve experienced what we’ll call here the all-or-nothing ketchup quandary. You know, that moment when you reach for a new glass bottle of ketchup, remove the cap, and turn the bottle practically upside down — and then nothing happens. Intuitively, you shake or tap the bottle, and then suddenly your food is completely coated in ketchup (unless your reflexes are really good, of course). In this blog post, we […]
Water Purification Using Ozone
Water purification is the process by which chemicals, contaminants, and sediments are removed from dirty water to make it clean, and there are many processes through which this can be done. What you might not know, is that ozone molecules can be used as a means of disinfection in the purification process. “Ozonation” has been used to purify water, kill germs and bacteria in food, and even get rid of bad smells. Not only does ozonation provide clean water without […]
Upgrading the Nuts and Bolts of the Electrical Grid
The electrical grid describes the network created for producing electricity, transmitting it and delivering it to the consumers. A “smart grid” is an electrical grid that gathers information on the suppliers and consumers automatically to improve efficiency and sustainability in the system. As the automated technology improves, the hardware that physically connects the electrical grid together must improve as well. This hardware, the “nuts and bolts” of the grid, is comprised of transformers, cable joints, terminations, bushings, and fault current […]
Fluid Flow: Smooth Optical Surface in Minutes
Ultra-precise optical components require blemish-free surfaces that often cannot be achieved by the machining processes that grind these components. Fluid jet polishing (FJP) is a new technology being developed by Zeeko Ltd to replace the hand polishing that was often required. With the help of COMSOL, Zeeko was able to create a product that polishes the optical components in only ten minutes instead of an entire day, and without waveforms.
Injectable Microbubbles in Hydrology and Healthcare
Microbubbles filled with oxygen can be injected into contaminated lakes to restore the water quality. Typically, water is purified via water-treatment plants, but this microbubble technique is both inexpensive and more environmentally-friendly in comparison. As seen in a COMSOL News 2011 article, oxygen microbubbles are a researcher’s way of copying nature’s own self-restoration mechanism for cleaning contaminated lakes.
Wind Turbines in Urban Settings a Reasonable Idea
If I asked you to envision a wind turbine, odds are you’d picture a wind farm in some remote location. With good reason; that’s commonly where they are found. If you’re a student or faculty of Case Western Reserve University, on the other hand, you might think of the wind turbine you have on campus. Does it make sense to set up wind turbines in urban settings? These two researchers suggest that it does.
Efficient Heat Exchanger, it’s all in the Pipes
Nature is full of counter-intuitive phenomena; I’m fascinated by everyday examples like the one we talked about this summer, sinking bubbles in a pint of Guinness, but I have to say that engineering has its fair share of such examples too. The concept of heat exchange in coaxial pipes struck me as a student, as it showed me the relentless tinkering attitude typical of engineers wanting to optimize their design. In this kind of heat exchanger both streams, hot and […]
The First Flyer Optimized Using Multiphysics
December of 1903 marked the commencement of the Age of Powered Flight, and the Wright brothers went down in history. This was a time before personal computers and simulation software existed. Determining the optimal design of their airplane had to be done using physical prototypes and real-life experiments. What had the design looked like if the Wright brothers had been able to use computers and modeling software? Three researchers from Pennsylvania State University sought to find out how the design […]
Piezoelectric Energy Harvester Helps Increase a Car’s Efficiency
Much has been written lately about increasing the energy efficiency of cars. Batteries and fuel cells are very hot topics, and not so long ago I blogged about the University of Michigan’s use of solar cells to fully power a car. Yet, even on the smallest of scales, such as the sensors in your car, improvements are being made. Utilizing a MEMS (Micro Electromechanical System) piezoelectric energy harvester, Alexander Frej and Ingo Kuehne at Siemens Corporate Technology in Munich are […]
A Closer Look at the Physics Involved in Lava Lamps
Remember those retro desk ornaments of the 1960’s, those lamps filled with colorful wax that began to move when the lamp was lit? I’m talking about lava lamps, or as I like to call them, “Rayleigh–Taylor instability machines”. They may not be popular among today’s youth, but I still own one and I thought it would be interesting to look beyond the dyed blobs of wax and observe the physics involved in lava lamps.
The Secret Sauce in the Pipe Flow Module
We developed COMSOL Multiphysics to empower the engineering and science communities with state-of-the-art simulation tools. A key ingredient of this empowerment is flexibility. COMSOL users are already well aware of the full compatibility between various physics. This means you can put any (yes, really any) combination of COMSOL physics together. But that’s not the only way our multiphysics simulation tool is flexible.
A Cool Way to Consider the Environment
According to a study done by Brunel University in the United Kingdom, the food sector is among the top five energy-consuming industries. The transportation of food, including keeping it refrigerated, is one of the larger contributing factors to this energy-consumption and subsequent greenhouse gas emissions.