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Cryocoolers are essential systems in many space exploration missions to maintain propellants at cryogenic temperatures. Cryogenic recuperators are a key component of these cryocoolers and dictate the performance of the system. NASA is seeking to reduce the cost and increase the performance of cryogenic recuperators (also called Heat Exchangers) by utilizing Additive Manufacturing (AM) technologies.
Key problem(s) to be solved or system(s) to be designed.
Traditional shell and tube recuperator designs used in cryogenic systems are labor intensive to fabricate and manufacturing defects are a common problem. Can the GrabCAD community generate cryocooler recuperator designs with topologies that take advantage of the latest AM techniques to simplify the recuperator fabrication process without sacrificing performance?
Fig: Example of a Shell and Tube Recuperator
High-level requirements, assumptions and/or constraints.
Designs using AM technologies can take advantage of complex geometries with internal structures and channel sizes that would be difficult or impossible to fabricate with traditional methods.
In addition to cost reductions, designers should also seek to improve the thermal heat exchange efficiency, reduce mass and volume, reduce pressure drops, and consider innovative materials and material properties that can be produced through additive manufacturing.
Background:
NASA’s endeavors in cis-lunar, lunar, and Martian exploration all benefit from being able to use cryogenic propellants. However, maintaining the cryogenic temperatures that those propellants require poses a significant challenge as the vacuum and intense temperature variations in space render cryogenic cooling difficult. This challenge remains an obstacle for its efficient use as a mode of in-space travel.
NASA has identified that using advanced manufacturing techniques such as selective laser sintering, laser powder bed fusion, directed energy deposition, or others, could enable a reimagining of the traditional design of many propulsion system components. By applying these manufacturing practices, the goal is to enable novel design concepts that show improved manufacturability, performance, and/or mass.
Challenge Details:
The state of the art for recuperative heat exchangers is focused on increased heat transfer efficiency, compact designs, advanced materials, and integration with other cryocooler systems.
Some drawbacks to traditionally designed and manufactured components is the difficulty in the process and the manufacturing limitations. Traditional shell and tube models require precision engineering and energy recovery systems. Designs should reduce assembly and joining operations.
Innovations such as advanced coatings, 3D printing, optimized fluid flow management, microchannels, thermally anisotropic materials, and lattice structures can enable these devices to operate more efficiently than realized in current practice.
NASA has advanced many additive manufacturing technologies and is seeking innovative designs of an optimized recuperator that can take advantage of them https://www.nasa.gov/centers-and-facilities/glenn/nasa-additive-manufacturing-project-shapes-future-for-agency-industry-rocket-makers/. It is hoped that the winning designs from this challenge can be prototyped and tested to see how they compare to traditional designs. Advancing the state of the art of cryogenic systems is a key technology shortfall that NASA has identified for enabling long term storage of cryogens in orbit and in deep space.
Detailed requirements, assumptions and/or constraints.
The requirements for this concept are flexible to account for design innovation but are expected to be approximately as follows:
Reduced fabrication costs: ~50% (high priority)
Power Density: ~100 W/Kg
Effectiveness: >0.97
Operating temperatures: Cold side 90K, Hot Side 300K
Operating pressure: ~150psi
Secondary objectives would be to facilitate a working fluid (neon) at a rate >20 gm/s, and to minimize pressure drop.
Available CAD models, data, or other references.
While we can’t supply any specific models or data, some methods to meet requirements may include the use of topology optimization or generative designs with lattices, gyroids, or other complex geometries.
https://doi.org/10.1016/j.ijheatmasstransfer.2021.121600
https://cdn.techscience.cn/uploads/attached/file/20230628/20230628151101_64112.pdf
Key Criteria: Must be included in the submissions
In addition to the CAD Models, submissions should include a one or two page description document of the models that discusses materials, AM methods that are expected to be used and any other key information that may not be evident from the models alone.
Predicted thermal performance/CFD analysis are not required but are encouraged.
Evaluation Criteria and Weighting Factors
1. Feasibility of manufacturing, fabrication, and assembly of recuperator design and ability to lower production costs. (20%)
2. Incorporation of new or novel manufacturing technologies in model description. (15%)
3. Ability to meet efficiency requirements demonstrated by design. Bonus points may be awarded for CFD analysis. (10%)
4. Ability to meet power density requirements and demonstrated in a compact design. (15%)
5. Ability to meet operating temperature constraints demonstrated by design. (15%)
6. Ability to meet operating pressure constraints demonstrated by design. (15%)
7 . Quality and fidelity of the 3D models and renderings. (5%)
8 . How innovative the concept is when compared to other submissions. (5%)
REQUIRED DELIVERABLES (CAD files, reports, images, etc.)
CAD Files used in model.
ACCEPTED FILE FORMATS
● STEP, IGS or native Solidworks files are acceptable for CAD.
o If applicable, use a CAD file naming convention that makes it easy to determine how each file fits into the larger assembly.
● Any image files should be .jpg or .png
● Any animations should be compatible with embedding in Microsoft PowerPoint and separate viewing in Windows Media Player
● Any accompanying reports should be in .pdf format (can be saved from Microsoft Word to a .pdf).
● If zipped, the file compression shall be compatible with Windows 10 and not require any special software to unzip.
PAGE LIMITS AND FILE SIZE LIMITS
Total size of all files combined should not exceed 250 MB
ELIGIBILITY Solutions from countries listed as Type 1, 2, or 3 on the NASA Designated Countries List are Not eligible for monetary prizes. The list is frequently updated, and the latest version can be found here. This challenge is not open to NASA Personnel.
ENTERING THE COMPETITION The Challenge is open to everyone except employees and families of GrabCAD and the Sponsor. Multiple entries are welcome. Team entries are welcome. By entering the Challenge you: 1. Accept the official GrabCAD Challenges Terms & Conditions. 2. Agree to be bound by the decisions of the judges (Jury). 3. Warrant that you are eligible to participate. 4. Warrant that the submission is your original work. 5. Warrant, to the best of your knowledge, your work is not, and has not been in production or otherwise previously published or exhibited. 6. Warrant neither the work nor its use infringes the intellectual property rights (whether a patent, utility model, functional design right, aesthetic design right, trademark, copyright or any other intellectual property right) of any other person. 7. Warrant participation shall not constitute employment, assignment or offer of employment or assignment. 8. Are not entitled to any compensation or reimbursement for any costs. 9. Agree the Sponsor and GrabCAD have the right to promote all entries. If you think an entry may infringe on existing copyrighted materials, please email challenges@grabcad.com.
SUBMITTING AN ENTRY Only entries uploaded to GrabCAD through the "Submit entry" button on this Challenge page will be considered an entry. Only public entries are eligible. We encourage teams to use GrabCAD Print Pro (https://www.stratasys.com/en/software/grabcad-print-pro-trial/) for developing their entries. Entries are automatically given the tag "NASA_CryogenicFluidManagement" when uploading to GrabCAD. Please do not edit or delete this tag. Only entries with valid tag will participate in the Challenge.
AWARDING THE WINNERS The sum of the Awards is the total gross amount of the reward. The awarded participant is solely liable for the payment of all taxes, duties, and other similar measures if imposed on the reward pursuant to the legislation of the country of his/her residence, domicile, citizenship, workplace, or any other criterion of similar nature. Only 1 award per person. Prizes may not be transferred or exchanged. All winners will be contacted by the GrabCAD staff to get their contact information and any other information needed to get the prize to them. Payment of cash awards is made through Checks mailed to the Winners. All team awards will be transferred to the member who entered the Challenge. Vouchers will be provided in the form of Stratasys Direct Manufacturing promo codes. We will release the finalists before the announcement of the winners to give the Community an opportunity to share their favorites in the comments, discuss concerns, and allow time for any testing or analysis by the Jury. The Jury will take the feedback into consideration when picking the winners. Winning designs will be chosen based on the Rules and Requirements schedule.
INTELLECTUAL PROPERTY CONSIDERATIONS Copyright Stipulations o All material (including the CAD model itself and all written documents) must be free of any copyright restrictions. • Use only models, photos, or images created during the project unless you have obtained the right from the copyright owner for unrestricted use – do not blindly copy images from internet websites. • Images on .gov websites are often (but not always) public data; check before assuming it is public material. • CAD-Only Rendering Requirement – All renderings and visual representations submitted for NASA challenges must be directly generated from CAD software or other approved design tools. The use of generative AI to create or enhance submissions is prohibited. This policy ensures that all entries are original works and prevents the inadvertent inclusion of copyrighted material that may be present in AI generated content. Participants are responsible for ensuring their submissions comply with this requirement to maintain the integrity of the challenge and respect intellectual property rights. Include documentation of any usage permissions The Government is seeking a full government purpose usage license for further development of the concept. There is potential that the winning concepts could be included in follow-on studies.
SCHEDULE This Challenge ends on May 2, 2025 at 11:59PM Eastern Standard Time. Any Changes after the date will be considered as disqualifications.
EVALUATION CRITERIA AND WEIGHTING FACTORS (what you will base your judgment on). See evaluation criteria in challenge guidelines.
$3,000
$1,800
$1,200
$750
$250
Evaluation Panel Members:
Ben WIlliams - AST, Liquid Propulsion Systems, NASA
Luke Scharber - AST, Aerospace Flight Systems, NASA
Paul Gradl - AST, Aerospace Flight Systems, NASA
Will Sixel - AST, Heat Transfer, NASA
Lonnie Webb - Engineer, NASA
Engine Components Development & Technical Branch
Have an awesome idea for this competition? Want to win cool prizes? Sign-up now to upload your entries.
If you don't receive the email within an hour (and you've checked your Spam folder), email us as confirmation@grabcad.com
95 comments
Dario de Santiago 7 months ago
Hello, I have a few questions for this challenge. Does the model require any special type of connection? Flange, thread, a particular standard, and a particular diameter? I suppose this is important because the exchanger must be connected somewhere or to a test bench.
Will it be used with hydrogen? To take into account the issue of hydrogen embrittlement.
Braxton Moody 7 months ago
1 - What launch conditions shall be considered (250g)? Orientation during launch?
2 - What are the size constraints?
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Super excited about this challenge.
Melville 7 months ago
Greetings @Respected Organizers
Thank you for another opportunity and time for reading my query
I think there would be " feasible and economic" solutions "without gyroid"
Because there are "no prototypes" with bronze gyroids
Making a prototype with bronze gyroid would be dollars 10000 plus
According to my reading the best material for cryogenic recuperators
Would be aluminium copper and bronze
Again Sorry for being blunt
Making a gyroid would crash a medium 3d printer and defeat goal of cost effectiveness
Yasin Sumar 7 months ago
That's too much data to take into account for a B-Tech student, I’ll pass my turn.
Ben Williams 7 months ago
@Melville A gyroid does not necessarily need to be the design chosen for this project. There are other design solutions that can incorporate AM and potentially meet efficiencies seen by the traditionally manufactured recuperators.
Melville 7 months ago
Greetings
@Ben Williams
Thanking you for your reply
I have started preparing my entry
I have a research paper that similarly matches NASA requirements
Can I share this "open source Chinese research "
Testing is for water as working-fluid not cryogenic fluid
Anyways this research uses a gyroid and improved the efficiency by 50 percent
So Shell and tube wont carry negative marks right ?
Thanks for your precious time
Ben Williams 7 months ago
@Dario The recuperator would, theoretically be tested with a test bench. You do not need to model these connectors in detail for the purpose of this challenge. However, if it is easier for you, please use AN5202 and a 1" diameter. The working fluid will be neon.
Ben Williams 7 months ago
@Braxton We intentionally left these constraints ambiguous to leave the design space more open. We didn't want to make the design/analysis extremely difficult. But if those constraints would help:
1. NASA Standard GSFC-STD-7000
2. mass = ~55 lbm, volume = ~1325 in3
Ben Williams 7 months ago
@Melville Your design solution (and your design sources) are totally up to you! We will consider and score all design solutions but incorporating novel manufacturing techniques is a key component we're looking.
Marcelo Valderrey 7 months ago
Hello!
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I need to ask a question whose answer may seem obvious from the challenge statement, but it arises in an academic context where we encourage future conceptual designers to challenge the restrictions of the design request, to determine if any of them are eventually dismissable and, even more importantly, to avoid adding non-existent restrictions due to misinterpretations.
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With that being said, my question is: should I take the phrase "NASA is seeking to reduce the cost and increase the performance of cryogenic recuperators (also called Heat Exchangers) by utilizing Additive Manufacturing (AM) technologies." literally, interpreting that the use of additive manufacturing is imperative?
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Or, could I assume that the more important part of the phrase is "NASA is seeking to reduce the cost and increase the performance of cryogenic recuperators (also called Heat Exchangers)," and therefore consider different or hybrid options where CNC machining, casting, etc., and most likely, additive manufacturing could be present?
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Thank you very much in advance for any guidance you can provide on this matter, so I can pass it on to the group of engineering students who will be participating in this wonderful challenge.
Ben Williams 7 months ago
@Marcelo Please refer to the Evaluation Criteria and Weighting Factors section! Incorporating AM into your design is not explicitly stated in our evaluation criteria. So other innovative manufacturing techniques are fair game as well!
Marcelo Valderrey 7 months ago
Thank you very much for the reply!
Dario de Santiago 7 months ago
@Ben Thanks for the reply
Melville 7 months ago
Greetings
@Ben Williams
Thanks for reading my comment
Will work on my entry with dedication
Also thanks for Nasa testing standards document
Hoping my entry will inspire and add value to Nasa
Frando Vermaak 7 months ago
Hi I hope that you are doing well, Will both hot side and cold side fluids be at the operating pressure of 150psi. If not what pressure can we assume for the gas entering each of the inlets.
Dario de Santiago 7 months ago
El neon es un gas por arriba de los 24.6K
Melville 7 months ago
Hi @Respected Organizers
Greetings Once again
One more clarification
Which is the hot fluid and cold fluid
Is it both neon(gas) or neon with another ?
I require this data to improve my calculations !🙂
Any suggested chart for properties of Neon
There is very little "free data" on google on neon properties
I believe NASA would have reliable Neon Property data ?
One more query
Is Nasa acceptable to METAL 3d printing like copper/steel
Thanks
Biplap Deka 7 months ago
Sir, are OBJ and STL files allowed for model submission ?
Carlos J. Veloso 7 months ago
Melville, really??? Are you not reading the descriptions and requirements? Especially the last question, "Is Nasa acceptable to METAL 3d printing like copper/steel"
Melville 7 months ago
Greetings Mr Carlos
Sorry for sounding " stupid "
I have read the description It mentions "3d printing and additive manufacturing"
Not specifically copper and stainless steel "metal sintered printing"
Resin 3d printing is "cheaper " than " metal ones"
I am just clarifying whether Nasa has a metallic powder laser sintering 3d printer
Mr Williams Clarified heat exchanger will be a heavy device
Agustin Pernigotti 7 months ago
Hello,
With regards the materials that need to be used. In one of the papers provided I've seen a material widely used for cryogenic applications. However there not to much inf if any about the thermal conductivity at low temperatures. I've been researching about it but I only get thermal behaviour between 25°-400° C, and some only two values at 20° K and 40° K. With regards this information is it possible to give an advice on where to find it? Or some hint? Does the NASA know something about?
I know that the Conductivity has a linear behaviour, and at different temperatures the material structure changes, hence its coefficient. But it would be of some help to get this info or where to get it , if you know something.
Best Regards
Thank you
Melville 7 months ago
Greetings Melville here
I agree with Agustin with respect to the thermal conductivity
And also like to add "cryogenic thermal contraction" at low temperatures
Anyways taking these into consideration improves safety of heat exchanger
Some Steels are reported not to brittle at low temperatures cyclic loading
Ben Williams 7 months ago
Sorry for the lateness of the following replies, everyone:
Ben Williams 7 months ago
@Frando 150 psi will be the max pressure the system may see. But the operating range could be between 60 -150 psi. The cold side will likely be about 30 - 40 psi lower than the warm side
Ben Williams 7 months ago
@Melville Neon is both the hot fluid and the cold fluid. In a full cryocooler system, the system is closed loop so the neon fluid goes through both ends of the recuperator.
I do not have a specific NASA spec for neon but you can use properties you find on the internet. "Engineering Toolbox" is a helpful website for this.
Metal 3D printing of copper steel is certainly acceptable.
Ben Williams 7 months ago
@Biplap STL files are preferred but OBJ files are also accepted.
Ben Williams 7 months ago
@Agustin and @Melville I appreciate your thoroughness on this project. However, full cryogenic material properties is a bit too detailed for what we're looking for. While, choosing a material that can theoretically function under cryogenic temperatures is pertinent, it is perfectly acceptable to use material properties at room temperature for your analyses. Please note this discrepancy in your final submission and we will take that into account.
Agustin Pernigotti 7 months ago
Thanks Ben for your quick reply!
svpetar 7 months ago
This is shame! NASA is asking for help and not to pay!
Dario de Santiago 7 months ago
Question: Will the mass flow rate (20 g/s) be the same in both (refrigerant and cooled) neon circuits?
Ben Williams 7 months ago
@Dario Mass flow rate should be the same (20 g/s) at both ends (warm and cold) of the recuperator.
Marcelo Valderrey 7 months ago
I'll use @Dario's question to check if I understood correctly:
.
Is this a closed system in which neon circulates as an active fluid to cool the external fluid (oxygen, methane, etc.) and to cool itself?
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That is, the neon flow in a closed circuit is "distributed" between a "neon-external fluid" exchanger (to provide the main useful effect: cooling the fuel) and another "neon-neon" exchanger-recovery unit (to cool the neon itself before re-entering the compressor). This challenge refers only to the design of the neon-neon exchanger-recovery unit: is this correct, or have I misinterpreted the system?
Ben Williams 7 months ago
@Marcelo This recuperator would theoretically be a part of a cryocooler which would be used to maintain rocket engine propellants at cryogenic temperatures. This would be a closed loop system so neon circulates as the working fluid and cools a propellant tank.
I believe your understanding of the system is correct. This challenge only refers to the neon-neon heat exchanger that is used for working fluid temperature recovery.
Marcelo Valderrey 7 months ago
@Ben Williams, thanks so much for the reply.
Dario de Santiago 7 months ago
From what I understand, the heat exchanger is tested on a test bench where neon is used as the fluid to characterize the heat exchanger. This fluid is pumped at a pressure of 150 psi in a closed circuit. The cold neon enters at 90 K and the hot neon returns from the test bench at 300 K and re-enters through the inlet of the hot circuit of the exchanger to be tested. I assume they will have pressure and temperature recorders at each outlet. This way, the transfer efficiency and pressure loss can be calculated. All of this is an assumption based on the data provided. If it is correct, please confirm.
Ben Williams 7 months ago
@Dario this is exactly correct for component testing.
Dario de Santiago 7 months ago
Thanks @Ben. I think I understand better now. The key word is "regenerator." This exchanger would be used with the cooling fluid that enters and exits the cooling coil inside the tank and the pumping and cooling system. The goal would be to recover the temperature of the fluid before entering the pumping and cooling system to maximize the latter's efficiency.
Marcelo Valderrey 7 months ago
I'm sharing a diagram with my interpretation. If it's not correct, I hope it's helpful in getting to the true diagram. If what I think is correct, note that "our recuperator" works with a neon flow rate for cooling (I called it "flow rate 3") that is lower than the neon flow rate to be cooled (shown in the diagram as "flow rate 1+2+3")...
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Schematic of the "neon recuperator"
Melville 7 months ago
Greetings @Ben
Thanks for the quick replies to my previous queries
I will try to make this my last question
Is the Neon flow considered to be supersonic or subsonic
Your help is highly appreciated
It will be useful in my design checking before submission
Ben Williams 7 months ago
@Melville the flow is subsonic. The neon fluid is just the working fluid for the cryocooler - not the propellant for a thruster. The neon will not be used for any thrust generation.
Melville 7 months ago
@Ben Thanks for the quick feedback
Any upper limits of velocity 10 m/s or say 30 m/s
I understand we have to work between turbulent and subsonic flow
I hope this question will not violate "intellectual property"
Because in another mentions "Thieves are looking at these competitions to steal trade secrets "
Marcelo Valderrey 7 months ago
I am sharing an update of the possible general scheme, now operating in batches with the help of two neon tanks, which means the recuperator could always operate with the same input and output flow rate (20 g/s).
.
Schematic of the "neon recuperator"
Dario de Santiago 6 months ago
Yo creo es más parecido a los equipos que se usan en los grandes tanques de glp en el fondo del tanque hay una serpentina por dónde circula el refrigerante en nuestro caso neon. Entre ese serpentin y el equipo de refrigeración se coloca un intercambiador de regeneracion que lo que hace es regenerar la temperatura del fluido que retorna al refrigerador . Recuérdese que esté tiene un rango óptimo de funcionamiento el regenerador evita que te operé fuera del mismo. Y a máxima eficiencia
Dario de Santiago 6 months ago
El problema es que no a mayor superficie va a ser más eficiente hay un dimensionamiento de equilibrio entre la superficie , conductividad del material y flujo de gas. Demasiada superficie puede ser tan malo como tener poca superficie. O
Dario de Santiago 6 months ago
Hi @Ben, I have a question. Will you test the neon proposals in a simulation under the challenge's conditions? Or perhaps print some preselected designs and test them on a test bench? Or simply suggestively evaluate which solution might work and then test the winning solution.
Melville 6 months ago
Greetings @Ben
I highly agree with Dario's question How will finals be judged ?
Dario de Santiago 6 months ago
I see many of us are overwhelmed by another challenge: "South Pole Safety Designing the NASA Lunar Rescue System," because I recognize them by name. Well, greetings, colleagues, don't give up.
Ben Williams 6 months ago
@Dario and @ Melville, the submissions will be judged purely on a conceptual basis. There is a possibility that the winning submission will be printed and tested, but this is not guaranteed.
Dario de Santiago 6 months ago
ok
geo 6 months ago
3D metal printing is a new topic for me with many questions.
I read and found this machine for a Depowdering system for small tubes.
https://youtu.be/wNbrIWDaHDc
Dario de Santiago 6 months ago
Why has my proposal and model disappeared from the challenge?
Ben Williams 6 months ago
@Dario I'm not seeing your submission either. I never received an email saying that you submitted an entry. Try to resubmit if possible.
Dario de Santiago 6 months ago
Thanks @Ben. I've re-uploaded it. It was the first entry submitted to this challenge.
Melville 6 months ago
Hello @Ben and rest of competition Colleagues
Heartfelt and appreciative Thanks for all the Information and support
My Calculations are Finally complete
I will try to Upload three entries Simple intermediate and complex
May Nasa select what pleases it most
Fredrick Dismas 6 months ago
Am still a beginner 😎. I will once get to your levels @Dario, @Ben and other competition colleagues
Guido S 6 months ago
Hi, Does anyone have any good resource for doing the calculations?
Govind Singh 6 months ago
Hlo sir,
I want to know that how many entries are allowed for submission from one person??
Ben Williams 6 months ago
@Govind no limit on submissions per person!
Govind Singh 6 months ago
@Ben Thanks for reply. I am working on my design & submit in few days.
Dario de Santiago 6 months ago
Para los calculos el libro de Transferencia de calor y masa de Yunus y el libro de termodinamica de boles por la pagina 824 mas o menos . Metodos NUT y LMTD
Dario de Santiago 6 months ago
si no hay algunos xls dando vuelta en la web para calculos de intercambiadores
Dario de Santiago 6 months ago
si haces el calculo puedes obtener el area nesesaria de intercambio si el area de tu intercambiador se aleja mucho de ese numero tanto de mas como de menos su eficiencia caera drasticamente.
Alexander COsta 6 months ago
So, NASA is looking for a state-of-the-art, multiphysics complex solution paying only 3k$ to the winner?
Guido S 6 months ago
Thank you @Dario de Santiago
Magnus Condor Dragnir (MCD) 6 months ago
Hi dear Organizers
Please,
What is the minimum thickness for a CuCrZr alloy that your additive manufacturing technology can achieve?
Assuming that 150 psi corresponds to the working pressure of Neon at 90K, can we know what is the working pressure of hydrogen or is it static?
It's important for our design and simulations.
Politely
Magnus Condor Dragnir (MCD) 6 months ago
By hydrogen, I mean propellant/propergol (LH_2) who is probably the element that we want to cold.
Ben Williams 6 months ago
@magnus You can assume the pressure relates to both working fluids. You can also assume that the minimum thickness for AM CuCrZr is 0.060".
Donald Jacob 6 months ago
Hi Ben Williams
Please will .stl files be allowed? The software I am using for this complex geometry and testing has a very difficult time converting the model to a STEP file, and it also takes over 8 hours to do so. Much smaller models which I successfully converted already exceeded 1Gb in size.
Ben Williams 6 months ago
@Donald yes we'll accept .stl files!
george aziz 6 months ago
Dear @Ben Williams the software i am using produced 2 gb( .x_t) file and i am afraid that i have no idea how to reduce the size of my design can i submit the 2 gb file
Ben Williams 6 months ago
@George yes that'll be fine!
Magnus Condor Dragnir (MCD) 5 months ago
Please I'll send my own Sir.
a truly subtle and elegant solution.
I'm doing last simulation under Ansys Fluent.
Dhruv Gandhi 5 months ago
Hey @Ben !
I recently submitted my design but left out a few files (due to a file size limit clause in the challenge description)
If allowed, can I add them onto my submission (given there's still some time left)
Mostly an STL and IGES file and a couple of renders
Cheers!
Magnus Condor Dragnir (MCD) 5 months ago
Hello
I can't upload my .py file that I used for my calculations. The Grabcad platform says that this file tpe is not allowed and this message always appears even when I archive the file in .rar or .zip format
What to do?
Very politely,
MCD.
Magnus Condor Dragnir (MCD) 5 months ago
I have seen too many gyroids, including the models that I had thought of designing, and as it is of my own, I wanted to do things differently by proposing an even more elegant and original system.
Very Politely,
MCD
CryoFlux 5 months ago
Hi Ben. I'm having difficulty uploading my files. The only message I'm getting is 'File type not allowed'. I'm uploading SolidWorks files and I used the Pack and Go feature. Am I missing something?
Dario de Santiago 5 months ago
Uploading the files was a nightmare. I managed it with great difficulty, since by nature, an exchanger has many surfaces and intricate details, resulting in very complex surfaces, resulting in gigantic files. I see that the GrabCAD page doesn't render them, nor can they be viewed. Is this a rendering issue on the page? Or did I upload the files incorrectly?
Marcelo Valderrey 5 months ago
Hi Dario!
I couldn't even download a 500MB STEP file, thinking it was due to the size limitations imposed by the challenge. So I uploaded another "full" model outside the scope of the challenge, but GrabCAD wouldn't let me upload that STEP file either.
Dario de Santiago 5 months ago
Thanks @Marcelo. I hope if you can't see it at least you can download and open it.
Dario de Santiago 5 months ago
Hello, has anyone managed to get close to 97% efficiency by calculating for neon gas, for example, using the NTU method, the required area, and the outlet temperatures? Or did you just do CFD?
Ben Williams 5 months ago
Hi @everyone. Thank you for you participation in this challenge! We appreciate all the time and hard work you guys put into your submissions. Due to the large number of submissions (100), our prize announcements may be a little delayed. We will work diligently to have the winners announced as soon as we can. Currently, we are planning to down select to around 20-30 submissions by the end of this week then choose winners by 5/20 or 5/21. Thank you for your patience.
Magnus Condor Dragnir (MCD) 5 months ago
Yes Sir. I calculate them. Using NTU method.
- The required surface : 4.5 m²
- the outlet temperature: 210.97 K
- the length : 65.1 m
- power density > 100 W/m²
You can refer to my drawing to check it.
Helical Cryogenic Scavenger with Double Interlocking Rectangular Walls,KN
Dario de Santiago 5 months ago
Hello, for 97% efficiency, we should have had the same temperatures due to the eNUT calculation.
Circuit 1: Input: 90 K, Output: 295.5 K
Circuit 1: Input: 300 K, Output: 94.4 K
What can vary is the surface area, which will depend on the Overall Transfer Coefficient (U).
Dario de Santiago 5 months ago
Hello, can I make a request to the jury? I think someone else would agree? The request is that they take into consideration that the following may be exceeded: PAGE LIMITS AND FILE SIZE LIMITS
The total size of all files combined must not exceed 250 MB. The problem is that any heat exchanger for 97% efficiency using neon as a gas at the specified conditions would have surfaces between 2 and 20 m^2 with intricate structures, which implies that reaching those limits with topological structures or with fine details involves a large number of elements and surfaces in a CAD file. "Imagine the number of triangles an STL would have or the number of geometries in an STP." This implies file sizes greater than the limit, and especially if we count ferm captures, STL, STP, and other translations. There is no way unless it is a partial and poorly detailed construction that is nonfunctional.
Dario de Santiago 5 months ago
In case anyone is interested, I share the thermodynamic values of Neon. Neon Valores Utiles
Aytas 5 months ago
Hi team, When can we expect the results?
Ben Williams 5 months ago
@Everyone I will submit final rankings to the GrabCAD hosts by the end of the day. Sorry for the delay!!
Dhruv Gandhi 5 months ago
Thanks for the update @Ben Williams
Best of luck guys!
Melissa Yearta 5 months ago
@everyone.
Good day,
All winners results are now posted! Congratulations to all who have won.
Augustine Uyah 5 months ago
Congratulations to all the Winners!
And special personal congratulations, Nwobodo! I am really happy for your incredible success!
Marcelo Valderrey 5 months ago
Congratulations to all the participants and especially to the winners!
Ben Williams 5 months ago
Congratulations to everyone who participated! I understand this was a complex challenge so I deeply appreciate the time and effort everyone put into this. There were a lot of fantastic entries and it was a very difficult selection process.
Adam Bialko 4 months ago
Congratulations to winners and all who participated!
Jouni Huopana 4 months ago
Thanks you and congratulations to all who contributet to this! This was an interesting puzzle with a lot of different pieces which had to work together.
Floyd Marks Marks 24 days ago
This is an exciting challenge! Additive manufacturing makes it possible to rethink traditional shell-and-tube recuperators by introducing gyroid structures, lattice frameworks, and optimized microchannels. Such designs could improve heat transfer efficiency, reduce fabrication costs, and meet the Effectiveness > 0.97 requirement with lighter, more compact components.
For those who also follow innovative design solutions outside aerospace, Inland NW Windows explores efficiency and performance in a different industry.
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