zaterdag 16 december 2017

WAW Human Heated Vehicle.

When we conceived the convertible or 'cabrio' canopy of the WAW, it was nicely multifunctional:

 - when the rear of the canopy was up, it created a vacuum that sucked the air out and defogged the windscreen / visor, while cooling the head, which is the body's main radiator. It had three positions: closed, a little and a lot.

 - When closed, it functioned like the original WAW canopy with a motorcycle-like visor, as designed (AFAIK) by Frederik Vandewalle and later implemented on other velomobiles. 

The vacuum diffuser of the WAW canopy, closed off with foam tape.

The bottom of the nose was horizontal and underpressurized. This had the effect of creating an internal airflow from the overpressurized canopy, along the body from head to toes, exiting through the foot hole. So in winter you could choose a cool head and warm feet by closing the rear of the canopy.

It worked very well, but wasn't very well understood and not often adjusted. When the fourth generation of moulds was built, the feature dissapeared and I had other stuff on my mind. 

Another change was the shape of the underside of the nose. Originally it was designed for minimizing ground effect while maximizing stability. It did happen that speed bumps were hit by the nose, which was a problem until Dries and I devised the kevlar/carbon stressed skin architecture, which could just take the hit. Technically the problem was solved but the average customer wasn't entirely happy to scratch his expensive velomobile against a speed bump every now and then. Stephane of decided wisely to lift up the bottom a little on the WAW4 nose plug. This solved the problem.

The upturned bottom and the new canopy, however, changed the internal airflow entirely. While we were tailoring WAW360 to its Dutch owner yesterday, I heard he suffered from cold feet. So I recycled the old principle to restore the Human Heated Vehicle by closing off the rear of the canopy, and opening the bottom in a low-pressure zone. You can see the three holes in the foot hole cover under the nose. They can be closed off with some tape if needed.

This is a WAW360 on its way home to Holland: