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JorgeGT

6,161 karma · joined March 30, 2015

PhD Aerospace engineer, serial procrastinator.
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JorgeGT··on First atmosphere found on Earth-like planet in habitable zone of distant star
Yeah, it seems it's not permanent. You can go here: https://neo.gsfc.nasa.gov/view.php?datasetId=VIIRS_543D&date... and then click on the right side "0.25 degrees 1440 x 720".
JorgeGT··on First atmosphere found on Earth-like planet in habitable zone of distant star
This is the Earth last Wednesday at 0.25º resolution (roughly 28 km per pixel at the equator): https://neo.gsfc.nasa.gov/servlet/RenderData?si=2050444&cs=r...
JorgeGT··on Goodbye Visa and Mastercard: 130M Europeans switching to sovereign payment
Indeed Bizum is almost default now here in Spain, and for instance the equivalent in Sweden, Swish, is also almost default there. Went trekking into a national park, and the rangers will leave a number to Swish a bit of money if you want to use the fire pits; no other payment means.
JorgeGT··on German implementation of eIDAS will require an Apple/Google account to function
This is exactly how we implemented eIDAS in Spain. The government-issued national ID (DNIe) is an ISO 7816-compliant smart card. Latest versions are also ISO 14443-compliant for contactless reading. To use it, you just need a simple smart card reader or an NFC-enabled phone. https://www.dnielectronico.es/PortalDNIe/PRF1_Cons02.action?...
JorgeGT··on Khamenei Dead
The Ryan Doctrine.
JorgeGT··on The next steps for Airbus' big bet on open rotor engines
I talked with one of the aeroacoustic engineers working on it, she says they expect to match noise levels of current engines.
JorgeGT··on JuiceSSH – Give me my pro features back
Damn. I especially liked the cloud backup & sync. Any good alternatives?
JorgeGT··on Airbus A320 – intense solar radiation may corrupt data critical for flight
I don't know about the A320 but this was certainly the model for the Eurofighter. One of my university professors was in one of the teams, they were given the specs and not allowed to communicate with the other teams in any way during the hw and sw development.
JorgeGT··on Lenovo May Be Avoiding 'Windows Tax' via Cheaper Laptops with Preinstalled Linux
Lenovo has been doing this in Spain for quite a bit, and you can even buy them without any preinstalled OS at all for a lower price still. But at least here the option is typically available for ThinkPads rather than for more cheap consumer lines. Same with Acer. Dell offers Linux options but no "empty" option afaik.
JorgeGT··on Boosting Computational Fluid Dynamics Performance with AMD MI300X
It's tangential, but this is the first time I've seen Fluent installed by simply decompressing a tar, instead of executing their big installer.
JorgeGT··on Starship Flight 5: Launch and booster catch [video]
In reality few codes are capable of effectively parallelizing to so many computing processes. But, how cool would it be?
JorgeGT··on Starship Flight 5: Launch and booster catch [video]
It really depends on the problem to be solved (domain size, complexity of physical phenomena such as turbulence model, heat transfer, acoustics, multiphase flows, combustion, etc., number of time steps required...). In our case we perform for instance simulations of turbomachinery acoustics that can take 3-4 weeks running in a few hundreds of CPU cores, combustion acoustics simulations that can take a week or two running in 1k-2k cores...
JorgeGT··on Starship Flight 5: Launch and booster catch [video]
Oh no, apologies if that was the impression I gave!! I actually perform CFD simulations in HPC clusters, and in fact I'm an admin of the small cluster at my research institute =)

These are indeed heavy computations. What I meant is that VoF is one additional equation to be solved besides the N-S equations (either filtered as in LES or Reynolds-averaged as in RANS), the energy equation, your turbulence model equations, and so on. Certainly, not instantaneous at all, but simply an additional "simple" model that we can hook into our current way of doing CFD.

So, my point was, sloshing is a problem that we know how to simulate, although certainly you need HPC resources. Though, looking at those 100k NVIDIA H100 Elon has, I guess they have them! :P

JorgeGT··on Starship Flight 5: Launch and booster catch [video]
It is difficult, but there are modeling approaches that work, such as VoF (https://en.wikipedia.org/wiki/Volume_of_fluid_method). Basically, in addition to velocity, pressure, temperature, etc., you store an additional scalar in each cell of your computational mesh representing the liquid's volume fraction. Then, you solve an additional equation to transport that scalar.
JorgeGT··on Modeling study proposes a diamond layer at the core-mantle boundary on Mercury
I was thinking of the BFE...
JorgeGT··on JetZero: Ultra-efficient blended wing body jet
There's also the issue of ingesting the turbulent/detached boundary layer of the fuselage at high angles of attack, causing inlet distortions and the corresponding risk of compressor stall.
JorgeGT··on A list of Hacker News's undocumented features and behaviors
This update broke my workflow!
JorgeGT··on High-Resolution Lidar Images of Rivers and Deltas
Astonishingly, Harold Fisk did this in 1944 without any LiDAR: https://publicdomainreview.org/collection/maps-of-the-lower-...
JorgeGT··on The Fantilator Page
And if you prefer professionals, not amateurs: https://windshape.com/technology-2/
JorgeGT··on I built Excel for Uber and they ditched it
Even inside itself: filmmakers went to remote Los Angeles in the early 1900s because Thomas Edison, in NJ, held most of the patents on motion picture cameras and out west they were much more difficult to enforce.
JorgeGT··on This boat don't float (2009)
Maybe also a "Twain-version" of the title of Farley Mowat's novel The Boat Who Wouldn't Float?
JorgeGT··on Amsterdam to use “noise cameras” against too loud cars
Research-grade acoustic cameras from the leading providers cost anywhere from 50k-150k€. But they have much more than the "four microphones" the article cites, so I don't know which kind of solution they are implementing.
JorgeGT··on NASA's Software Catalog offers hundreds of new software programs for free
Yes, this is no-cost but not necessarily open source. NASA open source software can be found at: https://code.nasa.gov/
JorgeGT··on Intel's Downfall Mitigations Drop Performance Up to 39%, Tests Show
Well, that turns off all mitigations, so I guess it depends on whether you are concerned with some other vulnerabilities such as Spectre, etc.
JorgeGT··on Intel's Downfall Mitigations Drop Performance Up to 39%, Tests Show
If I'm reading this correctly, a Linux kernel parameter `gather_data_sampling=off` will be implemented to disable the mitigation: https://www.intel.com/content/www/us/en/developer/articles/t...
JorgeGT··on Names should be as short as possible while still being clear
The "clear" part is often the issue. My favorite example:

- In Mathematica, if you want to plot a vector field, you use VectorPlot[]

- In MATLAB, you use... quiver(). You know, because it holds a lot of arrows. Short and clear, eh?

JorgeGT··on MyNOR – The yet minor computer. No CPU, no ALU, one NOR-gate is enough
Furthermore, they sell a kit will all the parts =) https://www.budgetronics.eu/en/building-kits/mynor-single-bo...
JorgeGT··on Ask HN: What lesser-known accessories do you use with your computer?
Lenovo as well. They're called ThinkVision if someone wants to match that sweet ThinkPad aesthetics.
JorgeGT··on Spack – scientific software package manager for supercomputers, Linux, and macOS
How does it compares to other HPC software managers such as easybuild?
JorgeGT··on ChatGPT in Academic Writing
Forget the papers, if this thing writes grant applications...
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