A Lesson in CFD

  • October 15, 2014

There are certain moments in life when you see something and it just speaks to you. The first time I saw Computational Fluid Dynamics (CFD) in action, was one such time. I was watching a television show on Boeing Aircraft manufacturing. They were building a new jetliner and the documentary took the viewer behind the scenes to divulge how they come up with the design for a new jetliner. There was a segment on the shape of the wing. The goal was to reduce weight, increase lift, decrease drag; in turn these attributes would decrease fuel consumption, and increase efficiency. They used computers to simulate air moving over different shaped wings and could tell from these models which ones would be best suited for real world prototypes. Prototypes are extremely expensive to build.

After the show had concluded, I would think from time to time how fascinating that technology was, more specifically their use of CFD. My career provided me the opportunity to learn the CFD Analysis and design program. I am intrigued that it can save energy therefore creating value, make less of a carbon footprint by using less material goods and thus making an environmental impact Being Green.

CFD in its simplest form, is about describing the motion of a fluid, such as air, or water about an object. At its most complex, it can describe, in great detail, how fluid will transfer heat, transfer static electricity, change viscosity, produce sound, generate lift, how the water in your toilet will spin, how the water in the oceans will circulate, and even, how it will feel to be somewhere. It has been used for things as dynamic as solving aviation disasters, or space accidents. And as simple as, how your water mixes inside your faucet.

Automakers often use CFD to design cars down to the minute details, such as shape of the wiper blades reducing the cross section of the vehicle. These aerodynamic attributes save us money. A simple test one can do, not while driving of course, is to put your hand out the window of a moving car. Position your palm so it is facing forward in the vehicle, and feel how much energy it takes to hold it in place. Now turn your palm face down, you will notice that it is a lot easier to hold your hand in place.

CFD can be used to simulate stress of water over time on a bridge, or how air will interact with the bridge, think Tacoma Narrows Bridge. It can be used to make buildings safer, such as wind strength, or how quickly smoke will dissipate in a space enabling people to breathe.

This technology has become essential in the design industry for designing ships, aircraft, automobiles, wind turbines, even spacecraft that interact with the atmosphere in any way. As often as CFD is used, there are even more applications where it could be used, but is not. Besides external design of a building, the inside of a building can be refined with CFD to provide maximum efficiency of the HVAC system, such as a Data Center. It can be used to view the air dynamics inside a sun-facing atrium in order to minimize energy usage to cool the space, or likewise heat a space, in Operating rooms controlling spread of contagions via air routing and ducting. Other applications such as hydro dynamics in a fishery, clean room particulate prediction and control, or building offices or buildings for allergen containment.

The study and practice of CFD indirectly benefits us all on a daily basis. In the future, CFD will be used more widely in conjunction with like technologies such as simulation mechanical in designing parts for strength, while minimizing material needed and energy to build and therefore decreasing environmental impact. As the technology has evolved over the years the price has come down. With this combination, CFD is the next logical step in being healthier and green.

Author: Justin Durow
Mr. Durow has provided R&W with IT Specialist services relating to management of the following systems:  software, hardware, databases, Web resources, and network administration for over 8 years.  His knowledge in CFD Analysis has enabled R&W to expand with this service.
  • October 15, 2014