Aerospace

June 8, 2023 by AddUp

The Critical Role of Surface Finish in Fluidic Aerospace Applications: Unveiling its Importance for Heat Exchangers and Turbo Housings.

Author: Mark Huffman, Aerospace and Defense , AddUp

Heat Exchangers: Optimizing Thermal Performance

In the world of aerospace engineering, where safety and reliability are paramount, even the smallest details can have a significant impact. One crucial aspect that often goes unnoticed is the role that surface finish plays in parts and specimens, particularly those created with Laser Powder Bed Fusion (LPBF) technology. Surface finish plays a critical role in the fatigue behavior LPBF parts, influencing stress concentration, crack propagation, residual stress, contact fatigue, and specimen preparation. In this blog, we will delve into how surface finish affects fatigue, thermal integrity, and aerodynamic efficiency with LPBF parts, highlighting its immense importance to the aerospace industry.

In the realm of heat transfer, efficient airflow is vital for optimal thermal exchange between fluids. The surface finish of LPBF-manufactured heat exchanger components plays a crucial role in facilitating and optimizing airflow, thereby maximizing heat transfer efficiency.

A smooth and uniform surface finish achieved through LPBF reduces surface irregularities, such as roughness, burrs, or surface defects. These irregularities can disrupt the flow of air, leading to turbulence and increased pressure losses. By minimizing surface irregularities, LPBF technology allows for smoother airflow across the heat exchange surfaces.

With improved surface finish, LPBF-manufactured heat exchangers facilitate better contact between the fluid and the heat exchange surfaces. This enhanced contact promotes more efficient heat transfer, as it minimizes the formation of boundary layers. Boundary layers are thin layers of stagnant or slow-moving fluid that can form along the heat exchange surfaces. These layers act as thermal insulators, impeding heat transfer efficiency. By minimizing the boundary layer formation through a smooth surface finish, LPBF-manufactured heat exchangers enable more effective heat dissipation and temperature regulation.

Moreover, a high-quality surface finish achieved with LPBF technology helps reduce the potential for fouling or deposits on heat exchanger surfaces. Fouling occurs when contaminants or deposits accumulate on the surfaces, impeding heat transfer and reducing overall performance. The smoother surface finish provided by LPBF minimizes the adherence of contaminants and promotes easier cleaning, ensuring long-term thermal performance and efficiency.

Turbo Housings: Enhancing Aerodynamic Efficiency

Turbochargers are critical components in aerospace propulsion systems, boosting engine power and efficiency. The surface finish of turbo housings significantly affects their aerodynamic performance. Smooth and well-finished internal surfaces reduce friction and improve airflow, enhancing turbocharger efficiency. A high-quality surface finish minimizes turbulence, pressure losses, and energy wastage. It ensures optimal gas flow, which translates into improved engine power, fuel efficiency, and overall performance. By meticulously controlling the surface finish of turbo housings, aerospace engineers can enhance aerodynamic efficiency, resulting in better engine performance and reduced fuel consumption.

AddUp’s Solution

The integration of fine powder and a roller recoater system in AddUp’s LPBF technology in the FormUp350 can revolutionize the surface finish of aerospace components. By utilizing fine powder with smaller particle sizes and implementing a roller recoater for controlled and uniform powder deposition, manufacturers can achieve superior surface finishes, mitigate stress concentration points, and enhance the fatigue resistance of FormUp350-produced parts and specimens. These advancements pave the way for improved reliability, safety, and performance of aerospace components under cyclic loading conditions.

In fluidic aerospace applications, the significance of surface finish cannot be overstated. Whether in heat exchangers or turbo housings, surface finish optimization directly impacts thermal performance, aerodynamic efficiency, boundary layer separation, and corrosion resistance. By prioritizing a high-quality surface finish, aerospace manufacturers can maximize heat transfer, improve engine performance, enhance fuel efficiency, reduce drag, and ensure the longevity and reliability of critical components. The careful control and optimization of surface finish in fluidic aerospace applications pave the way for safer, more efficient, and more reliable aircraft and propulsion systems, ultimately advancing the capabilities and success of the aerospace industry.

May 12, 2023 by AddUp

The medical and aerospace sectors are expected to continue leading the adoption of metal additive manufacturing (AM) due to their high-value products and relatively low volumes.

The metal additive manufacturing (AM) industry has experienced significant growth in recent years due to an abundance of financial capital, advancements in technology, and expanded capabilities across the ecosystem. According to a report by Research And Markets, the global metal AM market size is expected to reach $11.1 billion by 2026, growing at a compound annual growth rate (CAGR) of 17.9% from 2021 to 2026. The North American market is projected to hold the largest market share during the forecast period further bolstered by government programs such as AM Forward.

The medical and aerospace industries are leading adopters of metal AM technology given the high value and relatively low volumes associated with their products. The global medical AM market size was valued at $1.5 billion in 2020 and is expected to reach $3.7 billion by 2025, growing at a CAGR of 20.5% from 2020 to 2025. Within this industry the technology is increasingly called upon to create customized and complex medical implants, such as spinal implants and hearing aids. For example, a growing number of major medical device manufacturers use laser powder bed fusion (L-PBF) to produce spinal implants with a unique structure that mimics the mechanical behavior of natural bone. This results in improved patient outcomes and increased patient satisfaction while adhering to the requirements of regulatory bodies and adhering to the exacting requirements of quality systems carrying certifications such as ISO 13485. AM is also reducing production times and inventory levels across the value chain, leading to cost savings for healthcare providers. All of which continues to warrant investment into AM by leading medical companies.

Maximizing Throughput for Medical Manufacturers

The spine industry has been utilizing AM on a mass scale for years. This is thanks to the size and quantity of implants which can be situated onto a build plate coupled with the volume of implants needed by the market. A challenge for other medical implants is achieving the level of throughput needed when sizes are large, and shapes are varied. Throughput is such an integral part of manufacturing today. When space is limited and need is high, AM machines with larger build plates and multiple lasers provide the ability to meet industry demand. For example, the FormUp 350 is a 4-laser system with a 350mmX350mm build plate and a powder module to reduce powder handling time. These features provide high productivity, saving time and overall production costs resulting in an improved process to mass-manufacture highly complex and/or customized medical parts.

The global aerospace AM market was valued at $0.9 billion in 2020 and is expected to reach $3.3 billion by 2026, growing at a CAGR of 21.6% from 2020 to 2026, according to a report by Research And Markets. Within this industry, metal AM is enabling the production of lighter and more efficient components, resulting in increased fuel efficiency, and reduced operating costs. For instance, Boeing publicized that the production of titanium structural parts for the 787 Dreamliner using metal AM was estimated to save $2 million per plane in weight reduction and manufacturing costs.

In Process Monitoring ~ A Game Changer for the Aerospace Industry

Within the aerospace sector, qualification and regulation of components is mandatory. Quality assurance software will be a game changer within this industry because additive manufacturing requires such rigorous testing and inspections which are often expensive and lengthy, impacting lead time and productivity. Companies, such as AddUp, are leading the way with process monitoring, providing confidence in the quality of parts with a full suite of quality assurance monitoring software to lessen, or even eliminate, the need for rigorous testing after a part is printed. As an example, AddUp’s software suite has 3 key elements. The first is a macro view of what is occurring inside the machine, visualized on an intuitive platform called AddUp Dashboards. Next is analyzing the execution of the production on a microscopic scale using Meltpool Monitoring to measuring dozens of parameters at a very high frequency. Lastly, Recoat Monitoring verifies and proactively corrects the powder bed during production, automatically. This type of software innovation will be instrumental in driving AM forward into industrialization, especially within highly regulated markets like aerospace.

We have many reasons to expect the metal AM industry to continue its growth trajectory in the coming years, with increasing demand from various sectors. For the right applications, the technology offers a multitude of advantages over traditional manufacturing methods, including faster production times, reduced waste, increased design flexibility, and ultimately product efficacy. While we might expect a slowdown in the near-term at the hands of tightening fiscal policy and the hang-over from financial market activities such as SPAC funding, the development of new materials and processes will drive the production of products with improved performance and the industry will continue its ascent to becoming a more widespread factory technology.

At AddUp, we remain bullish that the additive manufacturing industry remains a rapidly growing field with a promising future. The medical and aerospace sectors will remain leading adopters of advancing technologies and are driving demand for complex and customized components. Despite some near-term headwinds, the industry is poised for expansion in the coming years and is expected to play an increasingly important role in shaping the future of manufacturing. With its potential to revolutionize the way products are designed, manufactured, and delivered, additive manufacturing has the potential to drive significant economic benefits and create new and exciting opportunities for businesses, professionals, and consumers alike.

May 10, 2023 by AddUp

The interview with Zeda’s Director of Additive Technologies highlights how the flexibility of the FormUp 350 platform helps develop challenging applications and maximize productivity. The AddUp partnership is driven by a shared goal of large-scale part production and a commitment to open collaboration.

As the AddUp and Zeda partnership continues to grow, we get insight from Zeda’s Director of Additive Technologies, Rachel Levine, on how the flexibility of the FormUp 350 helps her develop challenging applications and maximize productivity.

1. Why are you passionate about additive?

In my junior year of college I took a class called Rapid Prototyping. From that moment on, I was hooked. Up until that point, I thought I was going to join the toy industry after graduating, as I’d already begun pursuing that career with a co-op the semester before. Once I saw the potential that Additive held, I couldn’t go back to an industry that relied on older, established technologies. My favorite thing about Additive is that there are still so many unexplored applications… there are still new frontiers that only a handful of people in the world truly have the knowledge, resources, and skill to explore.

2. What excites you about the AddUp partnership and FormUp 350 platform?

This partnership feels novel in a lot of ways. Our teams have been working together now for almost a year, and rarely have I had the pleasure of working with another company that is truly willing to engage in a partnership that works towards a greater goal. Too often partnerships are constrained by mistrust and an unwillingness to share information, but the Addup team has really committed to the partnership with open minds and a shared goal to drive towards large scale part production. Not to mention the FormUp opens the door to productivity improvements with its quad laser setup, open parameters, and long life filter.

3. How does AddUp Manager’s open parameters help Zeda engineers achieve their goals?

The right parameters make all the difference when it comes to productivity, buildability, quality, and material properties. Zeda understands that high volume, fine-featured medical production may require different parameters than large space parts because they need to be optimized for different requirements. The ability to edit parameters for lattice or other specialized features is something we hope to leverage going forward. Of course, all parameters must be validated and qualified against the needs of the product; a process that we are well versed in.

4. How does the FormUp350 differ from other platforms on the market?

FormUp350 is one of the only machines on the market that can run both the typical LPBF powder cut and a much finer cut of powder. This gives us flexibility to meet certain challenging applications we may come across in the future. I’ve also recently been given a sneak peek of some future developments that make me even more excited about our partnership and the benefits we will be able to bring to our customers.

5. How does the FormUp’s 350×350 platform and 4-lasers unlock applications for Zeda customers?

As a contract manufacturer, we see a wide variety of parts. For small parts, AddUp’s full-field overlap quad laser system allows us to improve productivity. The size of the platform allows us to reach a wider range of larger parts.

6. How significant is powder management to the overall process?

Without powder reuse, Additive becomes cost prohibitive for almost all industries. With proper validation and quality monitoring, AddUp’s internal powder loop allows us to move towards infinite reuse. The validation of powder life within AddUp’s internal system is a key project Zeda will be engaging in with AddUp.

7. How does the FormUp’s Autonomous Powder Module change this for Zeda?

Powder reuse becomes somewhat of a nightmare to track once powder leaves a system where it can then be accidentally exposed to moisture or contaminated equipment. For alloys such as Titanium, the offline powder movement and sieving process can also be dangerous. FormUp’s internal, inert system removes the common contamination risks as well as the exposure and explosion risk to the operator.

March 16, 2023 by AddUp

AddUp & Zeda Partnership: Interview with Rush LaSelle, AddUp CEO

The partnership between AddUp and Zeda is set to benefit key industries such as aerospace and medical sectors. With Zeda’s expertise in additive manufacturing (AM) and AddUp’s advanced FormUp350 print system, customers will have access to expanded capabilities, reduced costs, and improved manufacturing efficiency.

After the news of such a major deployment of FormUp 350 Powder Bed Fusion machines to Zeda, we wanted to sit down with AddUp CEO, Rush LaSelle to get his take on what this partnership means for AddUp, Zeda, and key AM industries moving forward.

Who is Zeda?

Zeda is a leading technology solutions provider with the objective to better lives by investing in cutting-edge technologies, innovative companies, and groundbreaking ideas. The company’s foundation combines expertise from diverse industries, including AM, nanotech, precision manufacturing, and incubating new ideas. Greg Morris and the ZEDA team bring the experience of being the first to use metal additive, specifically Laser Powder Bed Fusion (LPBF), to revolutionize the way aircraft propulsion systems are designed and serviced today. The founding teams have expanded the use of additive to unlock an increasing number of applications within the aerospace and to accelerate the qualification of medical devices helping to improve patient outcomes.

What key industries will benefit from this partnership?

The key industries of focus will be the aerospace and medical sectors. The AM market within the medical industry was valued at $1.5 billion in 2020 and is expected to reach $3.7 billion by 2025, growing at a CAGR of 20.5%, according to a report by Research and Markets. The global aerospace AM market was valued at $0.9 billion and is expected to reach $3.3 billion by 2026, growing at a CAGR of 21.6%, according to the same report. With this industry progression and projected market growth in mind, we are excited about our partnership with Zeda, a company that specializes in these sectors.

How will AddUp help support the growth of AM in the medical and aerospace sectors through this partnership with Zeda?

For Zeda customers, adding the AddUp FormUp350 print system to their stable additive equipment expands their capabilities and reduces the cost to deliver metal components. Initial applications will focus on the use of Titanium, Inconel, Aluminum, and Stainless Steel. Leveraging the FormUp 350’s four lasers, novel recoating strategy & monitoring systems reduce processing time during printing, delivers improved fine features & internal channels all while providing industry-leading surface finishes. These benefits reduce the need for support structures and reduce secondary processing costs and time. These features together will lead to a more efficient process for manufacturing AM parts for Zeda’s customers.

Our commitment to safer, cleaner, and more efficient manufacturing provides a foundation from which to realize design freedom and accelerated time-to-market with true industrial compliance. AddUp endeavors to deliver positive manufacturing outcomes using proven additive metal technologies forged by the uncompromising quality demanded by the factory floors upon which our company is built.

What does this partnership mean for AddUp customers?

For AddUp customers, the partnership affords immediate access to not only qualified FormUp printers for medical (13485) and aerospace (AS9100) within Zeda’s 75,000 square feet of manufacturing space in Cincinnati, OH, but offers a broad range of processes that envelope the printing process. These include; design support, simulation, cleaning, post processes, heat treatment and the requisite quality systems and traceability for the most demanding applications. With Zeda’s successful track record of serving regulated markets and the largest aerospace and medical customers in the world, companies can trust that they will get to market quickly and cost-effectively.

Greg Morris, CTO of ZEDA and Rush LaSelle, CEO of AddUp standing next to a FormUp350 system at ZEDA’s 75,000 square foot facility in Cincinnati, OH.

October 6, 2022 by AddUp

February 2017: among the many topics of the European Cleansky2 Call for Projects, one of them is attracting the attention of many entities, companies, and laboratories. Proposed by Liebherr Aerospace, it concerns the evaluation of improvements in new-generation heat exchangers using additive manufacturing.

With ten years of experience in additive manufacturing applied to complex products, particularly heat exchangers, SOGECLAIR Aerospace established a consortium to attack this project. SOGECLAIR is a high-tech engineering company in the aeronautical field. They lead the consortium, composed of AddUp, TEMISTh, and the Von Karman Institute for Fluid Dynamics (VKI). AddUp is a French industrial company specializing in metal additive manufacturing, TEMISTh is a French developer and supplier of customized thermal solutions, and VKI is a Belgian fluid mechanics laboratory.

SOGECLAIR’s consortium is working on project NATHENA, an acronym for New Additive manufacTuring Heat ExchaNger for Aeronautic. The project will last for four years with a total budget of €1.5M and will be 100% funded by the European Commission. Start date: March 2018.

CAD of a single flow channel and interfaces to the test bench

The objective is to develop two innovative heat exchangers for the aeronautical industry. The first one is a “pre-cooler,” allowing the pre-cooling of hot air taken directly from the turbo-engines of an airliner. It will be designed in Inconel 718 because it is subjected to very high temperatures. The second is a “cooler”, located further downstream in the air conditioning chain of the aircraft, allowing the air to be cooled again for later use. It will be designed in Aluminium AlSi7Mg, which performs well at the temperature range in the downstream location. The project aims to design heat exchangers as efficient as those made by conventional methods but with reduced mass and volume.

Single flow Aluminium 3D printed channel

The first step of the NATHENA project is to establish the state of the art of heat exchangers from the point of view of design, numerical simulation, optimization, bench testing, and the associated manufacturing techniques. This work allows us to build a solid database, a structuring element to guide and refine the architectural choices and the geometrical parameters of the future intensification structures developed and characterized during the project. These structures allow for an increase in thermal exchanges by extending the exchange surface.

The early technical studies led to the collaborative creation of the first CAD (Computer Aided Design) team of new intensification structures. To select the most promising geometries, the aim is to estimate their performance, factoring in manufacturing, mechanical, fluidic, and thermal perspectives. These are then integrated into the project’s standardized test channels, printed in Inconel and Aluminium on an AddUp’s machine, the FormUp^®350.

Instrumented single flow channel

Less than ten channels are printed in each material, one channel per intensification structure. These channels are then thermally tested on a test bench, and the experimental results are compared to CFD numerical simulations (Computational Fluid Dynamics). The principle: air at room temperature is introduced at the entrance of the channels while the heat exchangers are heated by a flat electrical resistor attached to one of their walls. Multiple sensors then measure the gas’s pressure, temperature, and velocity at different positions in the channels. These measurements are then used to confirm the validity of the numerical simulation models and to compare the performance of the different structures.

Through simulation and testing, the consortium gains a better understanding of the flows and heat transfers in different structures produced by additive manufacturing. The manufacturability of such geometries with many thin walls is evaluated as well. These first very encouraging results allow us to outline the most efficient heat exchanger architecture, offering the best compromise between manufacturability, mechanical strength, thermal performance, and fluid performance. All these results continue to build on the already established database.

Single flow channel test results and comparison with simulations for one of the Aluminium samples – left: linear pressure evolution, right: heat transfer coefficient

This first study on the representative channels thus launches a campaign of similar tests involving two hot and cold fluids. The goal is to characterize the performance of the chosen geometry in a miniature heat exchanger in which the hot source is no longer an electrical resistor but a hot air flow. The channels here will be in a crossed configuration.

Three two-fluid channels are printed: two in Inconel and one in Aluminium, for which the parametric intensification structures are calculated and adapted according to the airflow characteristics. The manufacturing of a very large number of thin-walled fins (several thousand), with the associated printing quality, dewaxing, and finishing requirements, is a real challenge. The channels are then characterized on a test bench, allowing once again to correlate experimental tests and numerical simulations.

Instrumental dual flow channel

Thanks to a homogenization method, these thermo-fluidic characterizations have enabled the creation of metamaterials (“Equivalent Porous Media” or EPM with equivalent volume properties) which simplify the numerical simulations, lighten the models, and reduce the calculation time. Correlations between numerical simulations and tensile tests of specimens, also produced in Inconel 718 and Aluminium AlSi7Mg, allow us to refine these mechanical metamaterials. Indeed, a heat exchanger is a system with numerous small and complex geometries in a large volume. Simulating them numerically can be very computationally expensive if such techniques are not used.

Schematic diagram of the double flow test bench

The next step is to integrate the most efficient intensification structure in two larger prototypes of heat exchangers (one in AlSi7Mg and one in Inconel 718). As in the previous step, the objectives are to improve performance and better correlate the results between numerical simulations and experiments on the test bench. The aim is to generate as much data as possible and to increase the knowledge of additive manufacturing applied to complex thermal equipment.

3D print simulation of a double-flow channel

Control tomography of a double-flow channel

CAD of a heat exchanger prototype and printed prototype in AlSi7Mg

All these simulations and experiments have enabled us to precisely determine the performance of the selected intensification structure and the internal architecture. The two final heat exchangers were designed to meet Liebherr Aerospace’s specifications accordingly. New tools and innovative methods had to be used to realize their CAD, considering the size of the designs and the very high number of integrated intensification structures (more than a million). The data generated by the test of the Aluminium prototype was also used to simulate the theoretical performance of the final exchanger and to generate a first CAD of the full part, with a volume corresponding to 12 printed prototype cells (see below).

In order to meet the performance requirements of the final part, a focused study was carried out based on the initial data from AddUp and adapted to the specific needs of this project. The specifications expressed by the consortium contain 3 major points:

Thin waterproof walls in IN718 (between 100 and 300µm)
Productivity increase
Surface finish on fins and channels <6µm

To master the constraints of this development, AddUp uses the latest generation machine (FormUp 350 – New Generation) allowing the use of 4 lasers as well as enhanced monitoring and tracking systems (sensor monitoring, recoating control, …). This data, coupled with the results of experimental measurements, have made it possible to define an operating range and a set of stable manufacturing parameters.

The complete heat exchanger was produced with a manufacturing strategy that allowed the simultaneous use of 4 lasers to increase the productivity of the laser powder bed fusion technology. This performance was made possible by the prior validation of the various key characteristics of the part (mechanical, thermal, dimensional).

CAD and prototype exchanger printed in IN718

Like the Aluminium exchanger, the Inconel exchanger was tested on a test bench to evaluate and validate the first models established for Aluminium. These experiments allowed us to study and highlight the impact of the roughness, but also to validate the first behavior models used during the simulations.

Illustration of thermal test bench (VKI)

The roughness-related deviation is considered in the heat flow simulations performed by Temisth. The calculations show a temperature distribution matching the data from the real measurements, validating the first models used.

Illustration of the simulated temperature fields on the cold side (left) and the warm side (right) _ Temisth

Experimental results on test bench – IVK

The size and details of the final complete exchanger (670x450x320mm) in Inconel 718 from the conclusions of the study show the possibility of integrating additive manufacturing for the realization of heat exchangers with performances at least matching that of current heat exchangers.

Technological hurdles overcome within the project :

Depowdering
Manufacturing strategy for thin walls
Manufacturing strategy to reduce surface roughness
Generation of a high air flow at -15°C
Temperature measurement mapping
Correlation between simulations and experimental measurements
Calculations based on experimental measurements to predict the aerothermal performance of fabricated exchangers
Management of large files
CAD methodology adapted to complex structures
Calculation methodology adapted to complex structures
The manufacturing strategy allows the use of 4 lasers on the same part

NATHENA: the consortium

SOGECLAIR aerospace

With its roots in aeronautics, the SOGECLAIR group designs, manufacture, and supports innovative solutions and products for transport in the civil and military fields.

Its R&D policy supports its participation in major future programs such as the development of the aircraft of the future and autonomous vehicles.

Its subsidiary, SOGECLAIR aerospace, is an international leader in the design and integration of high-value-added solutions for the aerospace industry. It designs, manufactures, and maintains the main components of aerostructures and aircraft interiors.

SOGECLAIR aerospace develops and deploys advanced materials and technologies such as thermoplastics and additive manufacturing.

With more than 1600 employees worldwide, SOGECLAIR aerospace has recognized know-how in:

Design and architecture of aerostructures and systems,
Design and manufacture of aircraft interiors,
Configuration management at the program, engineering, and industrial level,
Design and manufacture of simulated and embedded equipment.

AddUp

AddUp, created in 2016, is a joint venture between Fives and Michelin. It is a provider of complete industrial metal 3D printing solutions.

AddUp is involved in:

Design and manufacture of machines integrated into a complete production line, from powder management to the finished part,
Customer support for the production of metal 3D printed parts, to support investment projects in additive manufacturing for aerospace or additional production needs,
Cross-functional service activity, including the redesign of parts and additional services associated with the machine offering, helps companies find the most appropriate technical and financial solutions.

TEMISTh

TEMISTh is a company that specializes in developing and supplying customized thermal solutions. To do so, the company develops numerical simulation and optimization tools for automated heat exchanger design. This allows the company to develop new heat exchanger concepts to be produced by additive manufacturing.

Thanks to its location at the TEAM Henri Fabre Technocentre, TEMISTh offers various advanced manufacturing technologies such as metal and polymer additive manufacturing, foundry, machining, and assembly for function hybridization through brazing or friction welding. TEMISTh’s mastery of all these processes enables it to offer optimized and successful solutions to all its customers. All parts developed and produced can then be tested on TEMISTh’s thermal test benches.

The industrial fields in which the company operates are numerous: aeronautics, space, transport, oil and gas, and electronics.

Von Karman Institute for Fluid Dynamics

The Von Karman Institute for Fluid Dynamics (VKI) was founded in 1956 by Professor Theodore Von Karman as an international center combining education and research for the citizens of NATO countries under his motto “Training in research through research”.

Educational programs provided: Conferences / Courses / Colloquia, Short Courses, Master’s Thesis, Master of Research in Fluid Dynamics, Doctoral Program, and Applied Research Program.

The VKI undertakes and promotes research into experimental, computational, and theoretical aspects of liquid and gas flows in the fields of aeronautics, aerospace, turbomachinery, environment, and industrial and safety processes. Some 50 specialized test facilities are available, some of which are unique or among the largest in the world.

Research is conducted under the direction of faculty and research engineers, mainly sponsored by governmental and international agencies and companies.

Liebherr Aerospace

Liebherr Aerospace designs, develop, and manufactures air systems, flight control systems, and landing gear, as well as gears and gearboxes, and electronics for the aerospace industry. Liebherr Aerospace provides complete OEM customer services through a global network that offers equipment repair and overhaul, technical support and documentation, spare parts supply, and AOG service.

May 9, 2022 by AddUp

Additively Manufactured Static Mixer | Blog

Read how AddUp’s roller recoater and finer powder particle size distribution (PSD) provides finer features, improved surface finish and eliminates the needs for supports when producing a static mixer.

Written by: Nick Estock, Director of Applications and Business Development

Additive Manufacturing, like any manufacturing process, has its strengths and weaknesses. All processes typically have value-added steps and necessary secondary operations that are a consequence of their shortcomings. Support structures are one of these necessary evils of AM. They are part of the process but add no value to the final part. In fact, they decrease the value because support structures consume material and machine time but then need to be removed after printing. All of this reduces productivity and ultimately costs you money. So, let’s eliminate them! (OK, maybe minimize them..)

AddUp, a joint venture between Michelin and Fives, developed a system to do just that. Michelin has been utilizing AM since the early 2000s, long before I even knew what a 3D printer was (we didn’t have 3d printers or even smartphones when I was in high school). Michelin utilized the technology first to reduce the development cycle for their tire mold inserts, called sipes. Today, they produce over one million of these sipes a year for their production molds. Critically important features to these sipes are: the resolution down to 0.2mm features, shallow overhangs as low as 15 degrees, and surface finish as low as 4 Ra um, as printed.

So, when Michelin embarked on this joint venture with Fives how did they achieve such a high level of quality? They did so by developing the FormUp 350 as the only industrial Powder Bed Fusion (PBF) machine to utilize a roller recoater in conjunction with a finer powder Particle Size Distribution (PSD). Typical PBF technologies use a PSD ranging from 25-63 um. The FormUp can effectively manage, distribute, and spread powders down to 5-25 um. By using finer powders and a roller, AddUp achieves a better packing density of their build bed up to 70% dense. Combine this with high quality open parameters and you have a recipe to build finer features, better surface finishes and yes less supports, hassle free and right out of the box! What do I mean “right out of the box”? I mean no secret sauce, no special parameters applied in certain areas, and no slowing down the process. Design it, apply your standard parameters, load it on the machine and go!

Let’s take a look an example, a static mixer our applications team developed to illustrate this point better.

What is a static mixer?

Wikipedia defines this as:

“a precision engineered device for the continuous mixing of fluid materials, without moving components.[1] Normally the fluids to be mixed are liquid, but static mixers can also be used to mix gas streams, disperse gas into liquid or blend immiscible liquids.”

In other words, it is a pipe where two or more fluids are introduced at the inlet and carried across a series of “static” elements such as plates or paddles to homogenize the fluids upon exit. Why is this a great additive application? Because you can optimize and customize the design for any given application. Why is a static mixer a difficult part to produce additively? Because the mixing elements pose a problem when printed using traditional AM guidelines. Standard design guidelines for AM means these elements would have to be printed at 45 degree angles. This limitation would require to either elongate the mixing region of the mixer itself and/or add many more elements to achieve the desired performance. Either of these options mean you are no longer leveraging the advantages of additive and what’s left is an ineffective expensive part.

Static Mixer with:	AddUp Static Mixer	Standard AM Guidelines (45˙ fins)	Reduction
Overall Height	305 mm	654 mm	53%
Material Needed	738.5 cc	1583.82 cc	53%
Build Time	88 hours, 32 minutes	189 hours, 51 minutes	53%

The AddUp Static Mixer increased productivity by 53%!

But, what if you didn’t have this limitation?

The static mixer shown here was printed without these limitations. Our engineers designed this mixer with elements as shallow as 25 degrees without any supports while still achieving an acceptable surface finish. Not only that but they designed it in less than two weeks and achieved a first-time yield. How was this possible? AddUp’s roller and fine powder configuration coupled with robust parameters provide new design freedoms for the AM process.

As shown in Exhibits A and B, using a roller system in conjunction with finer powder, the AddUp system can achieve a reduction in surface roughness by about 10 Ra um for any given upskin/downskin angle when compared to medium powder PSDs with blade recoater configurations.

EXHIBIT A

EXHIBIT B

Don’t forget, this was achieved right out of the box and hassle free! There are no special downskin parameters. There is no need for advanced development that can take months and countless hours of engineering and machine time to achieve. These results can be accomplished using our standard, highly productive, bulk and contour parameters. With other machine OEMs, enhanced surface finishes or extreme overhangs often come at the cost of slowing down your productivity. That’s because they are using less laser power at a reduced speed to achieve such results, thus slowing down your productivity. This also introduces additional variables into the mechanical properties of your part. Instead of having a singular set of parameters, yielding a known set of mechanical properties throughout the entire volume of your part, you have created areas that can potentially exhibit different behaviors. The AddUp system achieves these results thanks to a better packing density of our powder bed and our roller with fine powder configuration.

Think this is all too good to be true? Try me! We have just completed the renovation of our Cincinnati facility, serving not only as our US headquarters but also as a technical demonstration center. From powder to part, our workshop has the full capabilities to run benchmark, functional prototypes and even production parts. Our team is ready to support our customers just tip toeing into AM to turnkeying an industrialized application.

Use the form below to tell us about your project and we’ll show you the AddUp difference! We look forward to the opportunity to “un-support” your applications!

Search

Heat Exchangers: Optimizing Thermal Performance