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Show HN: Olelo Foil - NACA Airfoil Sim

by rbrownmh on 5/20/25, 4:44 PM with 19 comments

Hi HN!

A while back, I started exploring ways to make aerodynamic simulation more interactive and visual for the web. I wanted something that felt immediate—intuitive enough for students, fast enough for hobbyists, and hackable enough for engineers. That’s how Olelo Foil was born.

Foil is a browser-based airfoil simulator written in JavaScript using Three.js and WebGL. It lets you interactively explore how airfoils behave under different conditions, all rendered in real time. Right now, it uses simplified fluid models, but I’m working toward integrating Navier-Stokes for more accurate simulations—and I’d love help from anyone interested in fluid dynamics, GPU compute, or numerical solvers.

I’m also building Olelo Honua, an educational platform focused on Hawaiian STEM content and digital tools. Foil is one piece of that larger vision—bringing STEM education into the browser with open, accessible tools.

Check it out, and if you're interested in collaborating (especially on the physics side), I’d love to connect!

  • by rbrownmh on 5/20/25, 8:47 PM

    Figure I'd drop this here - some other projects I'm working on currently:

    Seafloor LOD (infinite terrain generator): https://github.com/kanakawai-maui/seafloor-lod

    Olelo Honua (free LLM-enabled translation tool): https://www.olelohonua.com/

  • by observationist on 5/20/25, 8:27 PM

    For those of us who didn't know what these were, you can specify a 4 digit code that corrrelates with an airfoil shape, and here's how it works.

    http://airfoiltools.com/airfoil/naca4digit

  • by aa-jv on 5/21/25, 8:57 AM

    This is very fun - here's a small feature request: add the ability to define KFM airfoils.

    https://en.wikipedia.org/wiki/Kline–Fogleman_airfoil

    I experiment with these airfoil designs and it would be very nice to have a smooth way to see the various efficiencies/inefficiencies of various dimensions of KFM airfoil.

  • by hbrav on 5/20/25, 5:00 PM

    I have a background in fluid dynamics and may be interested in helping with this. Is there a way for me to contact you?
  • by ge96 on 5/20/25, 8:10 PM

    Oh damn that's trippy how you can move the camera haha I am the airfoil

    0990 chonker

  • by addaon on 5/20/25, 7:05 PM

    Unless you're planning to resolve the boundary layer and model separation (good luck...), you'd probably be better off using panel methods than NS. Look at XFoil or JavaFoil for available implementations.
  • by westurner on 5/21/25, 5:21 PM

    Notes re: CFD, Navier Stokes,

    "Deep Learning Poised to ‘Blow Up’ Famed Fluid Equations" https://news.ycombinator.com/item?id=31049608

    https://github.com/chennachaos/awesome-FEM4CFD?tab=readme-ov...

    >> Numerical methods in fluid mechanics: https://en.wikipedia.org/wiki/Numerical_methods_in_fluid_mec...

    jax-cfd mentions phiflow

    jax-cfd > Other awesome projects: https://github.com/google/jax-cfd#other-awesome-projects

    PhiFlow: https://github.com/tum-pbs/PhiFlow/

    We had a monochrome green aerodynamic simulation app literally on floppy disks in middle school in approximately 1999 that was still cool then. IIRC various keyboard keys adjusted various parameters of the 2d hull that was tested to eventually - after floppy disc noises - yield a drag coefficient.

    TIL that the teardrop shape maximizes volume and minimizes drag coefficient, but some spoiler wings do generate downward lift to maintain traction at speed.

    A competitive game with scores and a leaderboard might be effective.

    ...

    Navier-Stokes for compressible and incompressible fluids, but it's a field of vortices with curl so SQG/SQR Superfluid Quantum Gravity / Relativity has Gross-Pitaevskii for modeling emergent dynamics like fluidic attractor systems in exotic states like superfluids and superconductors and supervacuum.

    TIL the mpemba effect says that the phase diagram for water is incomplete because one needs the initial water temperature to predict the time to freeze or boil; those have to be manifold charts like HVAC.

    There's a Gross-Pitaevskii model of the solar system; gravity results in n-body fluidic vortices which result in and from the motions of the planets and other local masses.

    /?hnlog "CFD" :

    From "FFT-based ocean-wave rendering, implemented in Godot" https://news.ycombinator.com/item?id=41683990 :

    > Can this model a fluid vortex between 2-liter bottles with a 3d-printable plastic connector?

    > Curl, nonlinearity, Bernoulli, Navier-Stokes, and Gross-Pitaevskii are known tools for CFD computational fluid dynamics with Compressible and Incompressible fluids.

    > "Ocean waves grow way beyond known limits" (2024-09) https://news.ycombinator.com/item?id=41631177#41631975

    Also, recently I learned that longitudinal waves in superfluids (and plasmas) are typically faster than transverse standing waves that we observe in fluid at Earth pressures.