Optimizing the unseen: The art of CFD in industry

SINTEF blog post

Kristine Midtbø Søfteland, SINTEF Industry

What is CFD?

Have you ever noticed the mesmerizing patterns that appear when milk swirls through your morning coffee, or found yourself staring at the dancing flames in a fireplace? These are rare moments when we can actually see fluid motion in everyday life. Most flows, however, remain invisible. You can feel the wind and watch trees sway, but you cannot see the air itself the way you can see milk in your coffee. Still, just like the wind, countless hidden flows influence everything from ocean ecosystems to industrial processes. That is why understanding these movements is so important, especially in systems where flow affects performance and efficiency.

This is where Computational Fluid Dynamics, or CFD, becomes a valuable modelling tool. CFD makes it possible to visualize and calculate important characteristics of fluid flows, even when those flows cannot be seen with the naked eye. In the MODERATOR project, for example, CFD is used to help make data centers more energy efficient. If you read the previous blog post about the X-520 immersion cooling tank, you may remember that the project focuses on improving how heat is removed from computer components. By using CFD, it is possible to see how the cooling liquid moves around the heated electronics. This helps ensure effective cooling and supports smarter design decisions.

Why is CFD important in industry?

Industrial processes must be efficient, stable, and reliable to remain competitive. Even small changes can have a major impact, so every detail matters.

Take the design of an airplane as an example. The wings are shaped to provide enough lift for flight while allowing safe takeoff and landing. The body is designed to reduce air resistance, which makes it possible to use smaller engines. This reduces fuel consumption and lowers the overall weight of the aircraft, making it more efficient. To test and improve such designs before building physical prototypes, engineers often use CFD. It helps ensure that the system performs as intended while saving time and resources.

Photo: Shutterstock

In other words, CFD can help design systems that use less energy, require fewer materials, and operate more safely and reliably. By visualizing and calculating key parameters, this method provides insight into problems and solutions that would otherwise be difficult or impossible to detect.

However, it is also important to consider the limitations of CFD. Simulations often require simplifications in order to produce results within a reasonable time. These simplifications can affect both the calculations and the final outcome. That is why it is essential to understand how much trust can be placed in the results. Still, when used correctly and with care, CFD is a widely used and valuable tool for designing and troubleshooting industrial processes.

How do we use CFD simulations in the MODERATOR project?

As described in the previous blog post, the MODERATOR project plans to use the heat removed from the data center in a thermal energy storage unit that can supply nearby buildings and industries. In this project, CFD is used not only in the immersion cooling tank, as mentioned earlier, but also in the thermal storage system.

In the thermal storage unit, heat is stored by melting a type of salt known as a phase change material, or PCM. To make sure the heat from the data center is stored and later released efficiently, CFD is used to study how different physical properties of the PCM affect the time it takes to charge and discharge the system. These properties can include melting point, density, or thermal conductivity. By understanding how both the physical properties and the design of the heat exchanger influence performance, the system can be made more energy efficient and better suited for industrial use.

Since the storage unit depends on melting the PCM, it is important that the immersion cooling tank can deliver high enough temperatures. At the same time, the computer components in the X-520 must be cooled well enough to avoid damage. By combining CFD with process simulations, the project ensures that the system works as intended. This means that the electronics are safely cooled while the energy storage reaches temperatures high enough to melt the PCM. The result is a more energy-efficient solution that shows how data centers could become more sustainable in the future.