CFD Not Just for Rockets and Race Cars

Materials and chemical processing simulations performed by ANSYS CFD. CFD simulation software can help a lot of companies outside of the aerospace and automotive markets. (Image courtesy of ANSYS.)

With the growing democratization of simulation software, engineers have more and more options available to optimize the fluid flows associated with their products using computational fluid dynamics (CFD) technology.

Conventional computer-aided engineering (CAE) technology and in particular CFD software has been hard to use and expensive to acquire and maintain. As a result of these high costs, many traditional CFD customers reside in the high-value automotive and aerospace markets.

For decades, these two industries have been using CFD to gain fluid flow efficiency advantages both inside and outside the vehicle. These markets are not where the new CFD customers work. Whoever needs CFD in these markets likely has it already.

“Engineers outside the traditional CFD use case of ‘rocket ships and racing cars’ may feel overwhelmed,” said Bill Kulp, lead product marketing manager at ANSYS. “Regular companies are getting great results and are successful, even without dedicated expert groups to a CFD project. They are using sophisticated software to get valuable, unexpected insights into product performance that adds great value to the customer.”

By making CFD easier and more cost-effective, simulation companies like ANSYS can open CFD to unexpected markets and fresh customers. The use of flexible licensing and on-demand cloud HPC instead of the traditionally expensive HPC hardware enables these smaller organizations to afford the technology. Features such as apps, templates and streamlined user interfaces (UI) make the technology easier to learn, which opens up even more doors to small to medium businesses.

“Engineers need to carefully consider their first software purchase,” added Kulp. “They will be faced with critical tradeoffs including breadth of capabilities, support, cost and ease of use. Software choices can easily get ‘locked in’ as engineers build libraries of models and get comfortable with the UI.  It can be very difficult to change later when new capabilities are needed.”

The following case studies will outline how ANSYS’ CFD technology has helped new customers, outside of the automotive and aerospace world, improve their products.

 

Design Space Exploration Helped Astec Optimize Its Burner Gas Inlet

3D model of Astec’s hot mix asphalt burner. (Image courtesy of ANSYS.)

Astec Inc. designs of hot mix asphalt plants. It used ANSYS’ CFD technology to optimize its burner designs.

Performing this optimization was proving a challenge with Astec’s current CFD package. The tool didn’t have the ability to parameterize the assessment and run a design of experiment (DOE). ANSYS’ DesignXplorer was chosen by Astec to fill in this gap.

 “The integration of SpaceClaim and http:Fluent in ANSYS Workbench makes doing parametric studies much, much easier than it was five or six years ago,” said Andrew Hobbs, chief CFD engineer at Astec. “Having people [from ANSYS] who are doing support and working alongside you as a partner, that to me is the difference.”

ANSYS’ DesignXplorer assessed the design of the burner’s gas mixture. The DOE tool was able to modify the gas inlet using a parameter study. The parameters being tested defined the inlet hole pattern, tube radius, tube length, number of inlet holes and distance from the tube inlet to the hole pattern.

Using DOE algorithms, DesignXplorer was able to map out the design space automatically. This saved Astec a considerable amount of time getting the product to market than if they had stuck with their previous CFD tool. Every organization may need to optimize their products eventually, and for that, a CAE tool with optimization technology is ideal.

 

Using Cloud HPC to Reduce Turnaround Time of a Vertical Wind Tunnel

It’s a bird, it’s a plane, it’s the fruit of hard engineering labor and CFD simulations. (Image courtesy of Brian Wasserman.)

Who doesn’t want to fly like Peter Pan? Such is the thinking of KeelWit, designer of vertical wind tunnels that simulate the feeling of skydiving without the risk.

However, these thrill rides are too expensive, too large and too complex to rely on physical testing. And due to the inherent risk of using human guinea pigs, KeelWit relies on CFD simulations during its development cycle.

Unfortunately, these simulations are also large and multivariate. To track of the wind velocity, heat loss and air pressure accurately, KeelWit needed large meshes—which was proving a challenge for its on-premise HPC resources.

Simulation of one of KeelWit’s vertical wind tunnels. (Image courtesy of ANSYS.)

It was time to move ANSYS to the cloud—and its choice was Gompute’s ready-to-use HPC. Gomputer is an ANSYS partner which provides HPC and cloud solutions for the software’s users.

Using this cloud system, over 50 simulated operating conditions were tested to help optimize the design aerodynamically and thermally. KeelWit also reduced its development time by a factor of four.

“Using ANSYS Fluent software and Gompute HPC cloud resources, we reached the accuracy level our clients required for our turbulence and heat transfer calculations,” said José Maria Cancer, CEO of KeelWit Technology. “Thus we have been able to implement real modifications on [the client’s] equipment and thoroughly optimize our designs in a shorter period of time.”

Since ANSYS has the option to run its solvers using on-demand clouds, engineers are no longer restricted to the HPC hardware in their office. In fact, they might not even need one at all. This helps to open the doors to new customers like KeelWit.

Reducing Water Usage While Improving the Shower Experience

CFD simulations comparing traditional home showers (right) with the Nebia’s design. (Image courtesy of ANSYS.)

Home shower company Nebia’s water saving shower heads were inspired by jet engine nozzles, so CFD that was able to handle aerospace applications was exactly what was needed.

Using CFD simulation, the company accomplished two feats, the first being the reduction of water consumption by 70 percent and the second being a new misting shower experience which has received positive feedback from customers.

During the design phase, the Nebia team needed to overcome a significant CFD engineering challenge: heat transfer.

Unlike the aerospace application, however, Nebia couldn’t ignore rapidly falling temperature when fluid turns to mist – unless it wanted to sell only to desert cites in the US Southwest.

The droplets would cool down too quickly to give a comfortable shower experience. Increasing the size of the droplets would negatively affected the shower head’s signature sensation. At the time, Nebia was working with prototypes which took a week or so to design, build and test. The slow turnaround wasn’t letting the design iterations happen fast enough. This called for a CFD tool with multiphysics capabilities.

Using ANSYS CFX and ANSYS Fluent, the team was able to study the thermal performance of 12 design iterations in a day, which allowed for significantly faster multiphysics optimizations and trade-offs. In the end, the team managed to design a thermal distribution that had the right droplet sizes, pattern, flow rate and direction.

 

5 Tips for Choosing the Right CFD Software for Your Application

The more powerful your CFD software, the more it will cost. How do you know you are choosing the one for your operation? (Image courtesy of ANSYS.)

If you, like Astec, KeelWit and Nebia, are looking to expand your CAE tools with CFD simulation, then the numerous options available might be bewildering.

Keep in mind that the choice you make can affect your company for decades. Users will have to invest considerable time to become familiar with any CFD product chosen. They will develop macros, workflows and templates that revolve around the chosen option. As a result, the software will become rooted in the company and will be difficult to change. This makes the CFD software choice worth the thought.

To help, engineering teams should try to consider what the software will be used for as the company grows. If you are simulating complex products that can benefit from optimization, then avoid software that will limit your results to only pass or fail. Also, ensure that the CFD solution can handle scenarios such as turbulent flow, transient analysis, reacting flows, non-linear and non-Newtonian flows if they are applicable to the current or future products in your organization’s portfolio.

To ensure that the CFD option will meet your requirements, here are questions worth asking:

  1. Does the CAE software have capabilities that will support future simulation assessments your company will need?
  2. Does the CAE software have regular releases and updates to introduce capabilities and fix bugs?
  3. Are numerous training materials available live and online to guide engineers through new assessments and capabilities?
  4. Is there access to live, video and written tech support?
  5. Does the CAE software provider give best-practice creation assistance and support?

For more information on ANSYS' CFD capabilities watch the webinar: Serious CFD Calls for Serious Software.

ANSYS has sponsored ENGINEERING.com to write this article. It has provided no editorial input. All opinions are mine. —Shawn Wasserman