Jonathan French

⚙️ 𝗗𝗼 𝘆𝗼𝘂 𝗸𝗻𝗼𝘄 𝗵𝗼𝘄 𝘁𝗼 𝗷𝗼𝗶𝗻 𝘁𝗵𝗲 𝗱𝗶𝗳𝗳𝗲𝗿𝗲𝗻𝘁 𝗽𝗮𝗿𝘁𝘀 𝗼𝗳 𝗮 𝗡𝗔𝗦𝗧𝗥𝗔𝗡 𝗺𝗼𝗱𝗲𝗹? The most used joints by far are RBE2 and RBE3. You better not confuse them. I still remember my early days with NASTRAN—when I made a rookie mistake confusing RBE2 and RBE3 elements. Trust me, it wasn’t pretty, I ended up paying with 8 days of my holidays! 🔧 𝗥𝗕𝗘𝟮 𝘃𝘀. 𝗥𝗕𝗘𝟯: 𝗪𝗵𝗮𝘁’𝘀 𝘁𝗵𝗲 𝗗𝗶𝗳𝗳𝗲𝗿𝗲𝗻𝗰𝗲? •   𝗥𝗕𝗘𝟮 (Rigid Body Element 2): RBE2 elements create a rigid connection between nodes. They force all connected nodes to move together as a single rigid body. Mathematically you force the movement of several nodes (dependent) to move like the central node (independent). This is perfect when you need to simulate a stiff connection, like attaching a bracket to a structure. But be careful—using RBE2 can overly stiffen your model and lead to unrealistic stress concentrations. •   𝗥𝗕𝗘𝟯 (Rigid Body Element 3): Unlike RBE2, RBE3 elements distribute loads in a more flexible way, without adding stiffness to the model. Mathematically the move of the central node (dependent) is the weighted average of several nodes (independent). They’re ideal for simulating connections where you want to distribute loads across multiple nodes, like attaching a force to a surface area. RBE3 is great for maintaining realistic deformation while still accurately representing load distribution. 🔍 𝗟𝗲𝘀𝘀𝗼𝗻 𝗟𝗲𝗮𝗿𝗻𝗲𝗱: Each has its place in structural modeling—RBE2 for rigid connections and RBE3 for flexible load distributions. Understanding when to use each is key to accurate simulations. #Engineering #FiniteElementAnalysis #NASTRAN #StructuralAnalysis #RBE2 #RBE3 (*) Image credit: Nader Zamani in his Youtube channel

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"We're not 'stuck' - we're just not going anywhere." FUTURE #CTPSPACE #TRAVEL Future #CTPcraft won't need Reaction Control Systems (RCS) or deal with these types of systemic 'leaks' (https://lnkd.in/gWp4zfDt) such as these. All of these fuel values, hoses, thrusters are ALL potential points of failure. Each a liability (safety). In #space - not a good thing to trouble with. One major/minor fuel-line pressure/ pressurization or thruster issue and your entire craft is at risk! Those gimble points via RCS are ALL needed to orient your craft/attitude for reentry trajectory as well. Our future advanced #CTPcraft will NOT require RCS (sub)systems, monitoring systems, installation, thruster pods, thruster hose/lines, valves, fittings, flanges, or the weight or space required that could be dedicated to other ship's systems. THIS KID IS OUT OF HIS MIND! But who's listening to me? I'm just 'some freak with a 'theory'. Some nobody. Whacka-doo-froo-froo guy no one's ever heard of with some deceased obscure mentor thinks he's got the science used by #UFOs/#UAPs or the #nextbigthing. "Let's point fingers and laugh children! This 'Reso' idiot thinks #UFOtech he calls #CTPtech stands a chance to revolutionize the #spaceindustry! Nerve of that guy! And safer space travel to boot than present space capsules? Bah! What nerve!" (https://lnkd.in/e-8e6fAY) #newscience #innovation #futuretech #deeptech

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Check out the 2024 Hypersonic News, part of AIAA's Aerospace America Year in Review! This article, co-written by Liz Stein and me, highlights key developments in hypersonics.

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I was curious if Chat GPT would be biased in translation. This isn't a commentary on the Bible passage itself...but rather an exploration of the LLM's neutrality...where biases are prominent. (Christians of all sorts get upset about the passage here...so...this is not a sales pitch.) I was curious if it would use mankind instead of man...which is how modern Protestant bibles translate the passage. Now... if I use LLMs to translate the whole Bible from earlier texts, do I risk copyright infringement? 🤔 Translation below. 27 And God created man in His own image: in the image of God He created him, male and female He created them. 28 And God blessed them, and God said unto them: Be fruitful and multiply, and replenish the earth, and subdue it: and have dominion over the fish of the sea, and over the fowl of the air, and over every living thing that moveth upon the earth. #LLM #machinelearning #translation #bibles #copyrights #AI #artificialintelligence (moveth? Interesting choice don't you think?🤔)

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Is cutting and pasting from NASA's CEA code causing your pointing finger to become a workplace injury? Does having to repeat the same thermo-chemical equilibrium calculations over again after a slight propellant change give you nightmares? Want to calculate the optimum mixture ratio for a dual-fuel system, but don't have the time to perform the calculations to minimize NOx? Then give Cequel and pyrho a try. Cequel performs all of CEA's calculations as a dynamic Excel spreadsheet function, allowing for fast parametric studies or supplying problem specific parameters without cutting and pasting. Need Isp, ratio of specific heats, C* or the mass fraction of CO2? Multiple parameters can be returned with one function call. Once your spreadsheet is set up how you want to solve the problem, it can be easily updated for future problems. Pyrho is a python library that provides the same functionality to both python and MatLab scripts. By encoding your analysis according to how you want to solve the problem, when a change happens, just tweak the input parameters to re-perform the calculations. A tri-propellant mixture parameter plot is included as an example. For more information and to request a free 30 day demo, please visit www.praqsys.com.

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One of the really awesome things we've learned recently via simulation is that the so-called "Rotating Wall" technique from Penning trap science (https://lnkd.in/gT3gD-rd) also works in Orbitrons and can be used to stabilize both ion and electron rotating modes. Essentially this involves splitting up the walls into azimuthal sections and using phase lagged sinusoidal voltages so that the plasma sees "a rotating wall" which can be used to apply torques to the plasma and speed up or slow down the particles. This is super cool and a really big deal for future Orbitron plasma stability control! Video below of a simulation we did recently using rotating electric fields to stabilize a ring of electrons confined in an Orbitron.

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Did you know that RTX has its own internal Technical Networks!? These are legacy entities from the old Raytheon days where the Technical Networks were tasked with ensuring that professional engineers of like disciplines were able to communicate and share best practices across the company (which can be a considerable challenge in large companies). This year is the Mechanical, Materials, and Structures Technical Network (MMSTN) internal week long symposium. Last symposium there were over 600 professionals from within RTX gathered together (digitally since it was 2 years ago) to exchange knowledge and network. This year we hope to include even more of our engineering colleagues from Pratt & Whitney and Collins Aerospace as we locate in E. Hartford for this years MMSTN Symposium. This particular symposium as it is one of the first in person events that RTX will host on this scale since the pandemic ended. The symposium consists of a week long activities and presentations that encourage engineers to get together across business units and geographies and share a cup of coffee in rooting out their most pressing issues. This particular event is limited to RTX personnel only. However, we have a vendor showcase event that allows for vendors to come into the symposium and make a similar presentation on their technological capabilities and how those would be of benefit to RTX. These presentations are followed by a vendor showcase event where the attendees of the MMSTN symposium come in and ask questions and understand each vendors capabilities. If you are a vendor and want to participate let me know and I can get you some information on how to take part. RTX people be on the lookout for the announcement in your work inbox! If you don't get it by next week ask your closest work friend or manager. If that doesn't work ask me! Don't miss out on this awesome opportunity to submit an abstract and take part in the gathering.

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[50 days' free access!] [A paper with Yuan L. and Arjit Seth] Expanding the aerodynamic shape optimization (ASO) formulation to a mission-based one has enabled us to investigate the tradeoff between fuel consumption and trailing-edge noise (TEN), while taking into account the comprehensive flight operational spectrum of the aircraft. TEN---despite not being the most important noise source for aircraft---is a direct consequence of airfoil shapes, which should be considered in ASO. Our work demonstrates the interplay between aerodynamics, aeroacoustics, and flight operational variations, which was made possible by the mission-based platform. The results provide a strong basis and motivation to further enriching the platform with higher-fidelity models and more noise components. https://lnkd.in/ghiGv8Fk

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Ti-64 is a key materials for AM production for aerospace and defense applications. Did you missed the news before and during RAPID + TCT? Phase3D has correlated in-situ heightmap anomaly data to CT-detected defects! This is a huge milestone for the AM industry to be able to predict when defects will form in the part, while it is being printed. This work was done for the United States Air Force. You can learn more about the work by reading through the case studies below. Reach out to sales@phase-3d.com or Noah Mostow with any questions. #3dprinting #additivemanufacturing #aerospace

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I couldn’t figure out how to share this post so I did my best at cut copy and paste. One of the most fundamental concepts in quantum mechanics: the Schrödinger Equation. Whether you're a physicist, an engineer, or just curious about the mysteries of the universe, understanding this equation is crucial. What is the Schrödinger Equation? The Schrödinger Equation is a mathematical formulation that describes how the quantum state of a physical system changes over time. It's the foundation of quantum mechanics and provides insights into the behavior of particles at microscopic scales. 🕰️ The Time-Dependent Schrödinger Equation The time-dependent Schrödinger Equation : - Psi(x,t) : The wave function, representing the quantum state of a particle at position ( x ) and time ( t ). - ( i ): The imaginary unit. - ( h^bar ): The reduced Planck constant, a fundamental constant in quantum mechanics. - ( m ): The mass of the particle. - ( V(x) ): The potential energy at position ( x ). This equation tells us how the wave function evolves over time, capturing the dynamics of quantum systems. ⏳ The Time-Independent Schrödinger Equation For stationary states, where the probability distribution of a particle's position does not change over time, we use the time-independent Schrödinger Equation: Here's what this means: - ( Psi(x) ): The wave function as a function of position only. - ( E ): The energy eigenvalue associated with the state \( \Psi(x) \). This form of the equation is used to determine the stationary states and corresponding energies of a system, such as electrons in an atom. Why is it Important ? Understanding the Schrödinger Equation is crucial for several reasons: 1. Foundation of Quantum Mechanics: It's the starting point for almost all quantum mechanical problems. 2. Technological Applications: From semiconductors to quantum computing, the principles derived from this equation drive innovation. 3. Philosophical Implications : It challenges our understanding of reality, suggesting a probabilistic nature of the universe at a fundamental level. The Schrödinger Equation may seem complex at first glance, but it offers a profound insight into the quantum world. By understanding its principles, we open the door to countless possibilities in both theoretical and applied physics.

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We're hitting the ground running in 2025! Aero engineer Eduardo J. Alvarez, PhD is attending AIAA #SciTech next week - if you'll be there, don't miss his presentation: 𝐀𝐜𝐭𝐮𝐚𝐭𝐨𝐫 𝐃𝐢𝐬𝐤 𝐌𝐨𝐝𝐞𝐥 𝐟𝐨𝐫 𝐀𝐞𝐫𝐨𝐩𝐫𝐨𝐩𝐮𝐥𝐬𝐢𝐯𝐞 𝐂𝐨𝐮𝐩𝐥𝐢𝐧𝐠 𝐄𝐟𝐟𝐞𝐜𝐭𝐬 𝐢𝐧 𝐕𝐨𝐫𝐭𝐞𝐱 𝐏𝐚𝐫𝐭𝐢𝐜𝐥𝐞 𝐌𝐞𝐭𝐡𝐨𝐝 Eduardo J. Alvarez, PhD will be presenting an advanced actuator disk model for predicting aeropropulsive effects of ducted fans with the vortex particle method. Below, you can see our Whisper Jet with a flap deflection of 20° and a counter-symmetric aileron deflection of 5°, while the propulsion jet is being deflected by upper surface blowing to produce blown lift. This model unlocks a path for accurately predicting complex aeropropulsive effects through mid-fidelity aerodynamics methods. We're excited to share this research done between Whisper and the FLOW Lab at Brigham Young University with Andrew Ning. 📍 Bayhill 30 🗓️ Tuesday, January 7th 🕜 1:40 PM EST If you haven't already, register here → https://lnkd.in/e8mVp5aD. #whisper #quiet #electric #propulsion #aviation #AAM #RAM

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Those are not 'lights' on outer-hull perimeter of the #CTPcraft filmed here (https://lnkd.in/ehwEnkfR). Those 'lights' are part of the CEMAS™ Arrays which are part of the CTP Propulsion Systems (CTPPS) utilized to control/modulate Gravity via the CTP Energy Cycle™. DISCLAIMER: Providing this footage wasn't faked. "This was faked" lulz Whatever. #newscience #propulsionsystems #propulsion #deeptech #deeptechstartup #spacecapital #newspacecapital #newspace #newspaceeconomy #heiroftesla

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I rarely post about journal publications unless there is something special about it and this one…oh yes, it is! First and foremost, it is co-authored by Aderik Verraest, an Honors Program student of our Bachelor program (nowadays Aderik is doing his Master of Science) showcasing the high potential in science of our best students. Aderik had a great support and collaboration with Panagiotis Komninos, PhD Candidate of our group, who is the one to blame for all the great inspirations and applications of #deeplearning in #lightweightstructures and of course the master mind of #prognostics Prof. Nick Eleftheroglou who pushes everyday the boundaries of the field. As the paper speaks for its self, I will share the following: for the first time, a model #ISTRUST interprets the relation between raw #SHM data and RUL predictions justifying the hows and whys of the deep network. Bonus: the paper is accompanied by the full code. You can use it to test your raw #SHM data. #prognostics #diagnostics #realtime #deeplearning #realscience #aerospace #composites Delft University of Technology Center of Excellence in AI for structures Intelligent Sustainable Prognostics https://lnkd.in/gBkctC2E

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Thanks to Ron F. from General Atomics' Electromagnetics Division for inviting me to opine on the challenges and opportunities of space nuclear power and propulsion. As it turns out, we have quite a bit of both. Opportunities first. I've said it before but it's worth repeating: Elon and his superb team at SpaceX have dismantled the LEO bottleneck. And that has opened the door to innovations of every kind - at least in LEO. But what it's really done is enable us to envision how we will go to (and play in) higher orbits, offering us a chance to define what sort of infrastructure we will build the future space economy *on*. The future is not LEO - it's the entire solar system. So: It won't be chemistry or solar power that get us moving, not if we're serious about creating a gold rush to orbit. Both are too constrained and deficient (i.e., insufficiently energy- and power-dense) to rapidly and efficiently connect the dots in cislunar space, and provide the megawatts on demand we know we'll need, whether the use case is civil, commercial, or defense. That leaves us with nuclear - and it's going to be fission for awhile, despite noteworthy quantities of money flowing into fusion. We can make this work - but we have to get to orbit and prove ourselves now. If we don't? Well, sunk cost is very real (see SLS). If you have it, you use it - even if it doesn't make sense. Let's make sure that what we put on orbit makes sense - commercial sense, defense sense, civil sense. Challenges? Well, we're all capital-intensive plays with some uncertainty in our regulatory story and that combo tends to scare the 💩 out of most private investors. I'd love to be introduced to any visionary folks out there with some discretionary dollars who share my passion for the space gold rush and want to find a way to get involved that gets us out and moving during our lifetimes - while we can have some fun. We can do this. 🚀 https://lnkd.in/ezq6yv_G

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