stass
Joined 17 years ago
Karma
438
Submissions
182
Member since
Feb 14
Aspiring programmer.
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Comment · 1 year ago
I cheated a little bit and don't calculate the fluid dynamics in real time. Instead, I'm using force models from the excellent Aero-Hydrodynamics of Sailing book by Marchaj, which is sadly out of print. I then do iterative balancing of the drag force and combined drag/lift forces on sails until they converge.
Comment · 1 year ago
SailRhythm is a bit WIP, so didn't want to share too early!
Thank you so much for the detailed feedback. I do have plans to implement wind flow visualization and have a way to visualize forces as well. Controls a bit tricky to do, but this is definitely something I've been pondering. As you said, at certain headings the changes sometimes are too small to perceive.
Comment · 1 year ago
You get water graphics for free from three.js
Comment · 1 year ago
If other people are interested in sailboat physics -- this resource is a goldmine of information on how sailboat and sails work and physics around it: https://www.onemetre.net/Design/Design.htm
Comment · 1 year ago
Please!
Comment · 1 year ago
Definitely recommend taking an introductory ASA 101/102/103 classes from a local school! Will help you decide if you are into it while having some fun.
This is how I started.
Comment · 1 year ago
I built one recently to mostly help myself visualize how sail trim worked and how various boat controls like mainsheet and backstay affected sail shapes, various forces and boat performance. It uses a physics-based VPP and I calibrated it against Catalina 36 polar charts, so should be pretty precise!
I plan to integrate the simulator with the sail trim guide I'm building to help people learn.
It's a WIP, but accessible at https://www.sailrhythm.com/
Happy to answer any questions!
Comment · 1 year ago
There is a great school called Modern Sailing School in Sausalito. I highly recommend taking a class from them. I took one in the past and they are great!
Will help you figure out if you are into sailing or not.
Comment · 1 year ago
Not my demo! But I got inspired by it some time ago to build a simulator for monohulls which uses a physics based VPP to calculate the boat speed based on input controls like mainsheet, jib sheet, travelers, backstay and so on at https://www.sailrhythm.com/
It uses Catalina 36 Tall Rig as a base model for sailboat parameters and was calibrated to match ORC-published polars for it within 1-5% on both close, beam and broad reaches.
Mostly built it for myself to help me understand how less common control affect the sail shapes, angles of attack and boat heel and behavior in a visual way.
It's still WIP, but you might find it useful for yacht-specific stuff!
Comment · 1 year ago
Even still a lot of information is not online. I've been building a web sail trim simulator and had to hunt down a physical copy of the Aero-Hydrodynamics of Sailing book by Marchaj, because a lot of the formulas and models I needed to simulate the boat were not online, and what was online was often wrong.
Comment · 1 year ago
This site is an absolute treasure trove of technical material on sail and hull design, with a focus on model yachts but most of the physics scales up. It covers aerofoil theory (momentum, circulation, lifting line), sail twist, downwash, planform effects, Reynolds number, hull resistance, appendage design, VMG, and more.
Lots of spreadsheets and practical calculators too—bulb shape optimization, wetted surface area, simple VPP models. If you're into sail performance modeling or yacht design, this is one of the best resources out there.
Comment · 1 year ago
You can now automatically debug native apps from Claude or Cursor using LLDB.
Here it is automatically analyzing buffer overflow in a binary: https://x.com/full_duplex/status/1904770477698277847