CASE STUDYSLACatching theWind for aGreener Future
How Gulf Wind Technology pushes
wind energy forward with the helpof 3D printing.

You’ve probably seen them sprouting from the landscape or seashore. The white rotors of these modern-day
windmills slowly turn in hypnotic unison, making it hard to believe wind turbines produce much electricity. But that istheir sole purpose, and they do it well. According to the U.S. Energy Information Administration, a typical wind turbine
installed in 2020 creates enough electricity in 46 minutes to power the average U.S. home for one month.1 That kindof power generation wouldn’t be possible, however, without the turbine’s rotors – the blades or airfoils – that harness
the power of the wind.

Airfoil Design Challenges
The technology and engineering behind these expansive wing-like appendages are the expertise of Gulf Wind
Technology, a company dedicated to developing rotor design solutions to address current wind turbine limitations
and future needs. And like any technology, advancements are often borne out of a desire to improve the status quoor to solve a problem.

To illustrate, the U.S. Gulf Coast presents wind turbine manufacturers with several challenges. Wind velocities arehighly variable, ranging from very light to hurricane-force. To find a solution, Gulf Wind Technology partnered with aleading energy company with interests in the region to develop solutions to allow wind turbines to work effectively inboth conditions. The resulting collaboration formed the Gulf Wind Technology Accelerator, the most advanced rotor
innovation center in the U.S., which utilizes a state-of-the-art technology facility.
But how do you design, validate, and test rotors that can be longer than an American football field? Computational
fluid dynamics analysis offers a starting point, which provides a theoretical model. However, validating themathematical model typically requires wind tunnel tests using scaled-down rotor models. These models are usually
CNC machined or formed with a carbon-fiber lay-up applied over a mold. According to Gulf Wind Technology seniorproduct developer Joe Lotuaco, “we’re given a problem statement, and then we’ll scale it down, investigate it, anddevelop solutions.”

1. USGS. (n.d.). How many homes can an average wind turbine power? Retrieved May, 2024, from https://www.usgs.gov/faqs/how-manyhomes-can-average-wind-turbine-power

The immensity of rotor airfoils becomes apparent when they’re removed from the wind turbine.

The process sounds straightforward enough, but it also poses another challenge: pushing the limits of airfoil design
within the company’s tight development schedule. Making wind tunnel models with traditional manufacturing is not a
fast process and hinders the ability to iterate designs rapidly. When the objective is to optimize rotor design as
quickly as possible, machining or molding wind tunnel models is not the answer because the time between theproposal and test of a new airfoil can be months. “That was the main reason why we wanted to have our own
in-house, hurricane-capable wind tunnel, and why we want to manufacture our own test articles in-house,” says
Lotuaco. So for Gulf Wind Technology, making wind tunnel models with additive manufacturing provides the rightapproach.

3D Printing Provides a Solution
Manufacturing wind tunnel models with 3D printing
offers Gulf Wind Technology several benefits.
The first is shortening the design and fabrication
cycle, including the time to iterate and finalize thedesign. Second, 3D printing’s additive nature gives
their specialist engineers the unique advantage ofincorporating pressure taps directly into the models.
These small ports provide essential data on the
airfoil’s performance and are very difficult – andsometimes close to impossible – to incorporate in amachined or molded wind tunnel model.

A rotor airfoil model made from Somos PerFORM Reflect material
emerges from the Neo800 SLA printer.

“We’ve been able todesign the internal
structure of our test
articles to have all thepressure taps run to amanifold, which I can justplug into the pressure
scanner. Then it’s easy toswap between models,”says Lotuaco. “I don’t see
how they could havebeen done in a traditional
way without doing a
multiple-section model.”The precision and durability of the Somos PerFORM Reflect resin allows engineers to incorporate small ports to measure air pressure along theairfoil’s surface.

“We’ve been able to design the internal structure of our test articles to have all the pressure taps run to a manifold,which I can just plug into the pressure scanner. Then it’s easy to swap between models,” says Lotuaco. “I don’t see
how they could have been done in a traditional way without doing a multiple-section model.”Adding further praise to additive’s capability for these complex designs, Lotuaco adds, “I can definitely say that being
able to integrate a lot of those features and simplify how we set up the model, how it gets mounted into the load cell,and how we can design them into the model has been a huge game changer. It just simplifies the testing process
almost to the point where we’re being asked to do more and more testing.”
Another advantage of 3D printing is the wide berth of technology choices and compatible materials, ranging fromFDM® to powder bed fusion to stereolithography (SLA). For the wind tunnel application, available materials, surface
finish, and printer size were among the important decision criteria. After reviewing possible options with the teamfrom Prototyping Solutions, a 3D printing service provider serving the southeast U.S., Gulf Wind Technology chose
the Stratasys Neo®800 SLA printer. In particular, the capabilities of the materials helped tip the scale in theNeo’s favor.
“It came down to the size of the parts we need to makeand the material strength properties,” Lotuaco notes.
“We gave our chief engineer the data sheets for all theavailable materials and he analyzed which materials
would be capable. The Somos® PerFORM Reflect™
material was the only one that met the loads we wereexpecting,” says Lotuaco.

The Neo800 offers the large build chamber Gulf Wind Technologyneeds to print the wind tunnel airfoil models.

PerFORM Reflect is ideal for wind tunnel testing primarily because of its strength, stiffness, and temperature
resistance. These characteristics allow the airfoil models to withstand the wind speeds and resulting loads andsurface temperatures they experience during testing. But besides delivering a resilient and slippery aerodynamic
surface, PerFORM Reflect reduces the cycle time to produce a test-ready model. Its orange color provides theright finish to minimize light distortion and optimize particle reflection needed for accurate PIV (particle imagingvelocimetry) testing. Other materials have to be coated after printing, adding time to the process.

The Proof is in the Results
As is often the case in client work, timelines are tight, and that reality is no different for Gulf Wind Technology.
Fortunately, the Neo800’s speed in producing wind tunnel models helps the engineers meet their project deadlines.
Lotuaco explains, “When our CEO asked me to put together the business case for 3D printing, I compared it against
the traditional methods of CNC machining and composite lay-up. And it always came down to the time factor. Using
the Neo to make the same exact airfoil, same geometry and size, was on the order of 2.5 to 5 times faster to print
versus composite lay-up or CNC machining.”
PerFORM Reflect’s durability also played favorably with the small air channels used for the airfoil’s pressure taps
mentioned previously. Despite their small size, these orifices were also printed with integral threaded connections.
“The fact that we can put a decent amount of torque on them without stripping, I think that’s something that isunique with this material,” Lotuaco notes. The ability to print these ports right in the model also speeds up theprocess. Lotuaco affirmed this benefit, noting that adding these pressure-sensing channels to a traditionally madetest article would increase its lead time by several orders of magnitude.

A Technology That Applies to Any Industry
While this might appear to be a story about how 3D printing benefits the wind turbine industry, that’s not thecomplete picture. At a deeper level, it illustrates what’s possible at the nexus between innovative companies like Gulf
Wind Technology and the enabling technology of additive manufacturing.
When Joe Locuato learned that Formula 1 race teams use 3D printed wind tunnel models to optimize their cars’
shape, he made the connection with using the same process to refine wind turbine rotor design. The result is a faster,
more efficient means of developing the optimal airfoil shape to harness wind power in the Gulf of Mexico.

Like most businesses that adopt additive
manufacturing, once they grasp its capabilities, newapplication opportunities seemingly present themselvesat every turn. And that usually leads to a broadening ofadditive capabilities. When asked about Gulf Wind
Technology’s plans, Lotuaco sees several possibilities.
“One of the things we are looking at down the road is
not just getting more SLA capacity, but looking at thedifferent additive technologies that are out there andhow we might be able to apply them in the future forother things that we think we’ll need,” he says. “We arelooking at metal printing, and we’re looking at theStratasys FDM machines to print some of the highperformance engineering plastics like ULTEM™, thingslike that,” he adds.
The scope of available additive technologies and theever-expanding material capabilities give manufacturers
the tools to dramatically change how things aredesigned, tested, and produced for the better. Gulf Wind
Technology recognizes this, leveraging additivetechnology to help forge a greener future through better
wind turbine rotor design. But in the end, it helps
differentiate Gulf Wind Technology in its industry space.
And it’s a perfect example of how virtually any businessin any industry can use additive to capitalize on theadvantages and set itself apart.

The Neo 800 is big enough to print the large airfoil models
Gulf Wind Technology needs for wind tunnel testing.

Joe Lotuaco sums it up this way: “Customers see that
we’re not doing things the way they’ve always been
done. When they come to our facility and see that wehave our own wind tunnel and(additive)lab
setup,© 2024 thisStratasys.
All rights reserved.
Stratasys,the Stratasys Signet logo, FDM, Somos and Neo are registered trademarks of Stratasys Inc. PerFORM Reflect is a trademark
Stratasys, Inc. 9085, 1010 and ULTEM™ are trademarks of SABIC, its affiliates or subsidiaries. All other trademarks are the property of their respective owners, and Stratasys
that’s unlike anybody else. ofassumes
SoI thinkusing(additive)
asperformance, or use of these non-Stratasys products. Product specifications subject to change without notice.
no responsibility with regard to the selection,a tool shows that we are leveraging and using newtechnologies you don’t typically associate with wind.”

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