Emerging Capabilities

AddUp optimized the design of a rocket nozzle to improve the performance of a micro-launch vehicle.

Metal additive manufacturing can lead to fuel and production savings in aerospace. In this case study, you will see how AddUp optimized the design of a rocket nozzle to improve the performance of a micro-launch vehicle. 3D printing is already the future of the aerospace industry. Read the case study about an optimized design of a 3D printed rocket nozzle.

INDUSTRY

Aerospace

CHALLENGE

To print an innovative rocket nozzle to optimize engine performance in space

KEY BENEFITS

• Mass reduction
• Printed parts with complex geometries
• Resistance to high temperatures

Mass Reduction

Creative Shape

Function Integration

Performance

History: AddUp & Aerospace

In the aerospace industry, new design freedom that comes with additive manufacturing allows for lighter parts, leading to fuel savings. Customization opportunities and absence of tooling are also seen as an advantage in this industry, where production volumes are quite low. Aerospace experts believe that the performance gains and reduced production costs will lead to 3D printing taking over as the manufacturing method of choice in the industry.

One of the leading trends in the field of space transportation is the rise of smaller launchers, able to send payloads of less than 500 kg into orbit. It is one of the most promising aspects of the New Space: micro and mini launchers provide flexibility and responsiveness that make them a complementary solution to conventional launchers.

Challenges of printing innovative rocket nozzles

A nozzle is a component of a rocket responsible for producing thrust. Hot exhaust gases are accelerated from the combustion chamber through a tighter throat, then expanded out the exit. This process converts the energy in the combustion gases into kinetic energy.

The complete development of an orbital launcher engine is a long and complex process requiring several iterations of design, manufacturing, and static firing tests. This presents a demanding task from the project management side.

With the field of micro and mini launchers becoming such a competitive environment, rapid iteration is both a technological and commercial necessity.

Considering technical challenges: the high temperature inside a nozzle requires cooling the walls as close as possible to the heat source, to avoid any components melting. This cooling is usually done via tubes attached to the nozzle and becomes more complex when the nozzle is more compact to meet the propulsion needs of smaller launchers.

Solution for a 3D printed rocket nozzle

In rocket engine nozzles, the exhaust gases heat up to approximately 3000°C. During the design of the nozzle, it was important to keep in mind that any available alloys wouldn’t hold up when exposed to such high temperatures.

All the cooling functions where integrated into the nozzle, allowing it to conduct the hot gases while maintaining its shape and performance. Prior to combustion, the fuel acts as a coolant. The propellants are stored at low temperature and run through the internal channels of the nozzle before being captured and injected into the combustion chamber to be burned.

Results and benefits of additive manufacturing

The part was printed on a PBF (laser – powder bed fusion) machine, AddUp’s FormUp® 350. This system, with open parameters and an integrated powder recycling module promotes rapid iterations, reducing the time between builds by making build file preparation quick and easy. The several recoating systems (roller, brush, and silicon wiper) allow for minimal design constraints and a wide selection of metal powders. These advantages are crucial in the development of nozzles and other rocket components.

• Metal additive manufacturing made it possible to create complex, integrated cooling channels; something impossible with conventional techniques on small engines. This nozzle, which normally requires months of work with traditional welding methods, took only 49 hours to produce. The experts at AddUp chose to use Inconel® 718 to print this new nozzle. This material has excellent mechanical properties and can withstand very high temperatures.

  Rocket engine designers can now iterate faster to improve the nozzle shape, running more tests in a smaller timeframe. Engineers can also take advantage of the new design freedom brought about by additive manufacturing, enabling them to push further to optimize engine performance.

The goal is to demonstrate an interest in the PBF technology to create heat exchangers with improved compactness, good thermal performance, and metal 3D printed in one go.

Answering the aerospace industry’s issues on thermal gear through the Powder Bed Fusion technology (PBF process) is what Temisth and PrintSky – the AddUp SOGECLAIRE Joint-Venture – propose under a partnership with the European Space Agency. In this study, the aim was to meet the needs of the space industry. The part was produced in aluminum on a FormUp 350 machine provided by AddUp.

Context

PrintSky is a joint venture between AddUp group, an expert in metal additive manufacturing, and SOGECLAIR, specializing in the integration of high-value-added solutions in the fields of aeronautics, space, civilian and military transport. Temisth is specialized in the development of custom thermal solutions customized using additive manufacturing. The goal for PrintSky and Temisth was to demonstrate their interest in the PBF (Powder bed fusion – laser) technology to create heat exchangers with improved compactness.

Used Means

Printsky has developed its own methodology for dimensioning heat exchangers to the given characteristics. In this example, the aim was to meet the needs of the space industry. The part was produced in aluminum on a FormUp 350 machine provided by AddUp.

Advantages of Metal 3D Printing

Metal additive manufacturing is relevant for thermal equipment. It allows for the creation of channels with complex shapes, thus improving thermal performance while reducing the volume. This heat exchanger has thin walls (250 μm) and double curvature channels that are impossible to produce by conventional techniques. The tests carried out on a test bench allowed us to validate the leak tightness of the part, as well as its performance, very high considering the compactness of the exchanger. PrintSky has obtained a partnership agreement with the ESA (European Space Agency) for the development of this aluminum part.

The AddUp Advantage

Metal powder in fine particle size, used here on the FormUp machine, allows surface conditions adapted to heat exchanges.

See how AddUp and PrintSky develop a good rigidity/mass balance with a high technical and economic value for an aeronautical part.

The CEA (French Alternative Energies and Atomic Energy Commission) has joined forces with AddUp to create the Famergie platform to help energy sector manufacturers develop projects for the production of parts using metal additive manufacturing. The first project resulting from this partnership is a demonstrator of a methanation exchanger-reactor. This device converts CO₂ into methane, which can be used as synthetic fuel. As the methanation reaction occurs at high temperatures and pressure, the design of the exchanger is crucial for the efficiency and control of the entire methane production. Read the case study about additive 3D printing of the aerospace support part using the FromUp 350® machine.

Context

PrintSky is a joint venture between the AddUp group, an expert in metal additive manufacturing, and SOGECLAIR specialized in the integration of high-value-added solutions in the fields of aeronautics, space, civilian and military transport. The CEA (French Alternative Energies and Atomic Energy Commission) commissioned Printsky to redesign a typically machined support part using the possibilities offered by additive manufacturing to reduce its mass. This support must also precisely ensure its functionalities to hold the equipment it has to support and resist the stresses it is subjected to.

Implemented Means

PrintSky was in charge of the design part of the project, developing its own experience and methodology to implement the characteristics of the metal part, in terms of mechanics and manufacturability. The production was then entrusted to AddUp experts who 3D printed the aerospace part using their FormUp350® machine.

Advantages of 3D Metal Printing

After topological optimization, additive manufacturing makes it possible to develop complex shapes, improve performance and reduce the volume of a metal part. It also allows the manufacture of very robust parts. Indeed, the material is added only where necessary, either to support forces or to ensure functionality such as fastening, support surface, or other. A good rigidity/mass balance with a high technical and economical value for an aeronautical part.

Results

The optimized support fulfills the same functions as the original support, but with a significant mass reduction, impossible to achieve with conventional technologies.

The use of fine powder allowed to obtain a good surface finish and finally the part was manufactured without support, which allows a significant time-saving in post-processing.

The AddUp Advantage

The mastering by AddUp of the material characteristics obtained on FormUp350® and of the additive manufacturing simulation tools has allowed us to anticipate the thermo-mechanical distortions and to obtain compliant parts after only one iteration.

INDUSTRY

Aerospace

CHALLENGE

Reducing the mass and lead time while optimizing
an Aircraft Floor Bracket

KEY BENEFITS

• 61% mass reduction of the part
• Part printed without any supports
• Industry leading surface finish

Reduced Lead Time

No Support

Weight Reduction

This proof of concept demonstrated by Add Up showcases the value of using Additive Manufacturing (AM) for aeronautics by applying topological optimization to an aircraft floor bracket.

History

An aircraft floor bracket secures the cabin floor to the fuselage and is present in large quantities in all aircraft. AddUp developed this proof of concept demonstrator to illustrate the value of using Additive Manufacturing for aeronautics by carrying out a topological optimization study with no supports. This part traditionally weighs around 3 kg and is typically machined from a 12 kg metal block.

Challenges

The weight of an aircraft poses various challenges, including structural integrity, fuel efficiency, payload capacity, and performance during takeoff and landing. Excessive weight can strain the aircraft’s structure, increase fuel consumption, limit payload capacity, and require longer runways.

Safety considerations, such as balance and stability, are crucial, and the cost and economics of weight must also be considered. To address these challenges, aircraft designers and operators focus on using lightweight materials, efficient designs, and operational practices that strike a balance between weight reduction, performance, and safety.

In most metal 3D printing machines, supports must be added to the part to produce surfaces with an inclination of less than 45° from the horizontal. These supports represent a significant cost and contribute to the time of part delivery.

SOLUTIONS

Topology optimization, the mathematical method that optimizes material within a given space with the goal of maximizing performance, was utilized to remove significant amounts of material.

First, a CAD model was created, incorporating the desired shape and the stress constraints the part needs to withstand.

Next, topological optimization algorithms evaluated the stress distribution throughout the part and systematically removed excess material from low-stress regions while reinforcing high-stress areas.

This resulted in a lightweight design that maintains structural integrity under anticipated loads. The part was then printed on the FormUp 350 powder bed fusion machine, using a fine powder and roller combo to reduce the need for supports. This combination also provided a smooth and uniform surface finish, which plays a critical role in the fatigue behavior LPBF parts and reduces the need for post-processing.

The Results

By utilizing the fine powder and roller recoater combination found only on the FormUp 350, there were no support structures required; overhangs can go as low as 30° or even 15°. By removing the need for support structures, 250 g of raw material was saved. This reduced the build time by 3 hours and saved another 30 minutes for support removal. This also lowers the overall total lead time, an important metric in the Aerospace industry.

Build Time on the FormUp 350 (at 50 μm)
11.50 Hours

Weight Reduction
From 3 Kg down to 1.17 Kg
A 61% weight reduction!

Raw Material Savings
10.83kg

Saved Time
3+ hours