The Waveless Hull - History to be rewritten
Three years of uninterrupted research
For ages the common knowledge has been to to keep wetted surface low in order to get a really fast displacement boat. This lead to the construction of the "parabolic" hulls like used in the "V"-series.
This all could all change with the invention of the "Waveless" hull. The name is a bit misleading, as it is the only thing remaining from project with what all of it started - the wave interference hull. This project had the goal to create a half-glider which could be powered by human power while it is still scientific consens, that human power is not sufficient to sustain gliding speeds.
I always believed that there has to be a way how it is possible to create a human powered half-glider despite all technical problems and in the end I proved to be right.
How it works
Parabolic hulls with a semi-circular cross-section are a requirement which resulted from minimizing the wetted surface of a boat. Olympic single row sculls are the crown of optimization and feature an area of 2.1m² at an unpractical length of 7.8m. The "Waveless" hull originated from the idea to use a thicker aft section of the hull in order to reduce surface at the penalty of higher wave drag. In the end a product came out, which features up to 19% reduction in surface and ~30% in length while keeping resistance the same. If compared to shorter hulls than 7.8m, there even is a significant advance in the required power.
The reason for it to work with the relatively low human power is, that the hull creates no dynamic lift. This is the effect which is responsible for gliders to work, but it causes an effect of "going up a hill" which results in a high power consumption. The "Waveless" hull divides the upcoming water smoothly instead and and keeps a near laminar flow until it nearly arrives at the stern. There, a slight suction is created to help the laminar flow while recuperating some of the pressure in the water.
Although the hull can be built in all sizes ranging from 3.5-6.3m (based on 100kg displacement) there are plans to have following hulls readily available:
- 2x50kg Cat (4.15m) --> 440 Watt @ 5m/s
- 100kg Stab. Monohull (5m) --> 360 Watt @ 5m/s
Both hulls are designed to be cruisable all day at 3 m/s by any average cyclist.
If you plan to build hulls on your own, there is a mathematical formula by which the hull can be calculated for any specific purpose (length and weight scaleable).
Who is the designer?
I am Andreas Schönwälder MSc, age 31, from Vienna. I am an engineer for safety relevant electronic systems in the automotive sector. Apart from that, I also work as a commercial pilot and theoretic instructor for future airline pilots. My obsession for boats stems from a homebuilt "Seggerling", surely one of the best sailboats for two persons in the world.
A relative of mine asked me, if I could build a pedal boat faster than the commercial ones, but still so small and light, that his smallest child could handle it alone. At first it seemed impossible, but progressing with time it seems more and more likely.
If you are interested in this project and want to contact Andreas Schönwälder (designer) please tell us.
Our boat is faster than mine.