Sail-Trim Simulator

#1

Post by stass » Wed, Apr 23, 2025, 6:36 PM UTC

Sail-Trim Simulator
simulator.atterwind.info

Re: Sail-Trim Simulator

#2

Post by zeristor » Wed, Apr 23, 2025, 6:55 PM UTC

I guess I’m not the only person who opened the link from yesterday and didn’t see anything about sailing.

https://news.ycombinator.com/item?id=43756926

Thank you, you’ve resolved my despair.

Re: Sail-Trim Simulator

#3

Post by [deleted] » Wed, Apr 23, 2025, 6:57 PM UTC

zeristor wrote: post #2

I guess I’m not the only person who opened the link from yesterday and didn’t see anything about sailing. https://news.ycombinator.com/item?id=43756926 Thank you, you’ve resolved my despair.

[deleted]

Re: Sail-Trim Simulator

#4

Post by quaestio » Wed, Apr 23, 2025, 7:41 PM UTC

Very cool demo...

Most yachts have polar charts, and the speed is a function of sail area, heading, wind speed and direction amongst other things. Are you considering calculating estimated boat speed based on given conditions and controllable variables?

Re: Sail-Trim Simulator

#5

Post by stass » Wed, Apr 23, 2025, 7:59 PM UTC

quaestio wrote: post #4

Very cool demo... Most yachts have polar charts, and the speed is a function of sail area, heading, wind speed and direction amongst other things. Are you considering calculating estimated boat speed based on given conditions and controllable variables?

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!

Re: Sail-Trim Simulator

#6

Post by stass » Wed, Apr 23, 2025, 8:34 PM UTC

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

Re: Sail-Trim Simulator

#7

Post by philips » Wed, Apr 23, 2025, 8:35 PM UTC

I am a lake sailer. And without landmarks or anything it is impossible for me to perceive the boat as moving.

Re: Sail-Trim Simulator

#8

Post by derbOac » Wed, Apr 23, 2025, 8:36 PM UTC

philips wrote: post #7

I am a lake sailer. And without landmarks or anything it is impossible for me to perceive the boat as moving.

Even some kind of wake or something would help.

Re: Sail-Trim Simulator

#9

Post by m_herrlich » Wed, Apr 23, 2025, 8:44 PM UTC

You can set the wind to 0 and the speed somehow stays at 35 knots, I don't know much about sailing but that can't be right

Re: Sail-Trim Simulator

#10

Post by cladopa » Wed, Apr 23, 2025, 8:45 PM UTC

A great project, but it needs some kind of grid movement and rocking, foam or something so you can perceive its movement.