What Happens When Optimized Geometry Meets Limitless Manufacturing

June 7, 2021

Part of what makes the work we do at Velo3D, so rewarding is that we serve as facilitators for some of the most cutting-edge technological advancement anywhere in the world. Our support of the aviation, energy, and space industries in particular presents unique challenges and opportunities to expand the understanding of the capabilities of metal additive manufacturing (AM).

Our recent collaboration with Launcher, a company committed to building the world’s most efficient rocket, and engineering simulation leader, Ansys, offers an exciting showcase of how we achieve the seemingly impossible through advanced software and revolutionary metal AM solutions.

“I’m really privileged and honored to be a part of this effort,” says Gene Miller, Senior Applications Engineer for Velo3D. “The ingenuity that Launcher is bringing to the table is really doing something unique; and I’m proud to be able to enable that, and really just stand on the shoulders of giants.”

The latest installment of our Velo3D VELOVirtual series features a conversation between Miller, Max Haot, Founder & CEO of Launcher, Andre Ivankovic, Mechanical Engineer for Launcher, and Sunil Patil, Industry Lead for Turbomachinery and Propulsion at Ansys, as they discuss the development of mission-critical parts used in Launcher’s Engine-2 (E-2) liquid rocket engine.

Watch the full presentation below:

Getting to Know the E-2 Rocket Engine

Launcher’s E-2 project is unique in its ambition: it aims to be the highest performance liquid rocket engine—running on liquid oxygen (LOX) and kerosene (RP-1)—in the world. Its end use will be as the central thrust component for Launcher’s Light rocket, which is set to take its first test flight in 2024. The E-2 aims to be a best-in-class engine for launching small satellites, with the largest thrust, lowest propellant consumption, and lowest cost per pound of thrust in the industry.

Another forward-thinking aspect of the E-2 project is its reliance on metal AM. Launcher has leveraged 3D printing and AM at every stage of development, which keeps the project low cost and, perhaps most importantly, optimized for mass production.

For the turbopump, Launcher utilized Velo3D to manufacture key components including the pump outlet housing, which was printed using Inconel 718, and a LOX pump inlet housing, printed in aluminum alloy F357. The flexibility in materials and the ability to print with limited supports enabled a level of freedom and control over the manufacturing process that would’ve been vastly more costly and labor intensive compared to traditional manufacturing. Each component was manufactured at a separate contract manufacturing facility emphasizing the flexibility of Velo3D’s contract manufacturing partner network.

Engineers at Launcher had strict requirements for their printed parts. For example, they required the impeller used in the LOX pump to be highly balanced in order to spin at 30,000 rpms, in cryogenic conditions, while transporting liquid oxygen.

“I want to point out how significant this is. We’re dealing with a liquid oxygen media in the pump at 30,000 rpm at about one megawatt of power from the Turbine,” says Haot. “In this type of environment, at four thousand psi of discharge pressure, any anomaly, any rubbing between the rotor and the stator, can result in an immediate, rapid, unplanned disassembly.”

However, many metal 3D printers struggle to reach this goal due to the design limitations imposed by supports. To avoid the use of difficult (or even impossible) to remove internal supports, engineers are forced to tilt the impellers at an angle to complete the build. While this may result in a part that looks like a functional impeller, they are often out-of-round and impossible to balance within the tolerances needed for the final product. Velo3D’s ability to print without internal supports also means that we can print the impeller flat and, consequently, round. This was key to enabling the construction of Launcher’s inducer/impeller design.

To embark on such an ambitious project, Launcher enlisted a team of partners without whom their vision could not be realized.

First and foremost, the E-2 is being built and tested through an Air Force Small Business Innovation Research program in conjunction with NASA, which provided funding and the use of the Stennis Space Center’s test stand complex in Mississippi.

Launcher also enlisted Ansys, a technology partner, to aid in simulation models to ensure parts being manufactured with AM could withstand the parameters of launch conditions. Last but not least, Launcher utilized Velo3D to print the mission-critical parts needed for the LOX turbopump.

Harnessing Advanced Software

The journey of the turbopump at the heart of the E-2 required Launcher to leverage a number of advanced software tools to ensure the engine would be suitable for field testing.

“If we look at any liquid rocket engine that is capable of reaching orbit, the turbopump is one of the most challenging parts of the project,” Haot says, “or at the very least, half of the challenge. And if you’re talking about a turbopump for stage combustion closed cycle, that level of challenge increases.”

First, Launcher licensed a proven design that has performed more than 70 trips to orbit from the Zenit family of rockets, designed in Ukraine. Yet in order to build a turbopump within the parameters of their desired outcome, Launcher needed to take that initial design, adapt it, and test it. They brought in Ansys as a modeling tool to ensure that their translated designs could withstand the extreme conditions, particularly with respect to the pressure rise required for their design and the customized flow path they developed.

“Before we got into manufacturing, we worked with Ansys to simulate the performance of our flow path in our LOX pump,” Ivankovic says. “We wanted to do this to ensure that the predicted performance was in line with the desired parameters for our entire rocket engine system.”

Once the modeling phase yielded the desired results with respect to pump efficiency, pump head, and cavitation, the team was ready to manufacture the parts necessary for field testing. The testing phase was exceedingly beneficial because it helped inform the parameters of the manufacturing process, which removed the need for excessive test prints and iteration in the printing process.

“Rocket science sometimes can be daunting,” Patil says, “but simulation helps to at least make the design process of the critical components of the rocket engine relatively simple.”

Melding Advanced Software with Next-Gen Manufacturing Processes

With optimized, model-tested designs in hand, the Launcher team was ready to begin the manufacturing phase to get their turbopump set for field tests. Because of the nature of the parts, they were leveraging metal AM to produce, they turned to Velo3D.

Our ability to achieve low angles and high-quality internal channels with minimal supports enabled the production of Launcher inlet design, combined inducer/impeller assembly, and the volute outlet.

Part of the challenge with a project like Launcher’s is delivering on designs that have already gone through so much modeling, refinement, and iteration. With the Velo3D full-stack solution and synergy between our FlowTM software and Sapphire® printers, however, we were able to deliver on even the most complicated designs.

“The last thing we want to do is go back and say, ‘Nope. We can’t build this. Redo something,’” Miller says. “In this case, we didn’t have to do that at all. We took the geometry as optimized, as designed, and printed without compromise.”

With the help of Velo3D and Ansys, Launcher’s field tests proved successful, meeting or exceeding all metrics of efficiency. The project is currently in testing phases for a Velo3D printed inducer/impeller, which will further deepen the contributions metal AM is making towards Launcher’s end goal of their E-2 project and Light rocket.

Our work with Launcher and Ansys is just one example of what can be accomplished when next-gen software and modeling combine with revolutionary manufacturing processes in metal AM. The sky is literally no longer the limit.

If you’re interested in learning more about how Velo3D advanced metal AM can transform your manufacturing process, get in touch with one of our expert engineers today.

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About the Author

Amir Iliaifar

Director of Content

Amir Iliaifar is the Director of Content at Velo3D where he oversees the production and distribution of Velo3D’s global digital content marketing initiatives. Prior to joining the company, Amir worked for a leading professional drone manufacturer, several SaaS companies, and as an automotive tech journalist. He holds a Master of Arts in Digital Communication from the University of North Carolina at Chapel Hill.