‘Downwind faster than the wind’ is a ground breaking and intriguing book by Nicholas Landell-Mills, an independent researcher in applied physics, which explores the theory of sailing in a new and perhaps controversial way that breaks with established models.
His analysis refutes several assumptions by showing that fluid mechanics fails to explain the forces on a sail, that a sail is not a wing, and the main force created is not perpendicular to the sail.
Subtitled, ‘Sailing explained by Newtonian physics and Galilean relativity’ Landell-Mills says the Newtonian approach is significant as it provides new and useful insights, which challenge the prevailing sailing solutions based on fluid mechanics and resolving long-running nautical conundrums, including how a boat can sail downwind faster than the wind.
Landell-Mills begins by analyzing the basics of sailing and airflow, before moving into how Newtonian mechanics relates to sailing with numerous examples and calculations. He then discusses Galilean relativity, and talks about the famous Blackbird wind-powered vehicle.
The fourth chapter is probably the most contentious as he highlights and exposes how false theories of sailing have been perpetuated. He then analyses hydrofoils in the final chapter.
The abstract for the book reads:
New analysis shows how Newton and Galileo provide a straightforward and useful explanation of sailing.
According to Newton, the sail re-directs a mass of air of the apparent wind backwards to create a backward force (Force = ma). The reactive equal and opposite forward force pushes the sailboat ahead.
According to Galileo a boat can sail downwind faster than the wind for the same reasons that it can sail upwind faster than the wind. Each tack is simply the mirror image of the other one. This is because in both situations the sailboat experiences a headwind, and the true wind is moving backwards relative to the boat.
When sailing both upwind and downwind, the sail extracts momentum and energy from the true wind by slowing it down. That’s it.
Downwind faster than the wind’ is available through Amazon stores: mybook.to/DWFTTW
ISBN: 978-1-912724-24-6
GBP 10 / € 11.95 / $ 14.95
Some sample pages are available on Amazon.
Also available to wholesalers and bookstores through Ingrams.
The book has received a great review in Surfer Today here: https://www.surfertoday.com/windsurfing/a-new-theory-on-sailing-downwind-faster-than-the-wind