foils

Kitefoiler Tow Test – Feb 2

2/2/11

Another tow test today after Joe and Damon repaired and modified the J-foils. We experimented with different crew weights and different positions for that weight, at various speeds. The adjustments seemed effective–the boat was stable under all parameters.

We put different GPS and tow tension sensors on both the Kitefoiler and Protector this time so that we could compare several sensor options. The load cells on each boat were in general agreement. The GPS receivers often reported different speeds, but this reflects the relative motion of the two boats. The peaks in line tension appear when the speed of the Kitefoiler drops enough for it to drop down from the foils. The segment in the attached graph shows the boats’ […more]

Kitefoiler Tow Test

1/21/11

Today the kitefoiler was put into the water for the first time. It floated well and we were able to get a sense for its handling while recording load and speed data. The boat got up onto its front foils at around 16 knots, which required approximately 150 kgf of tension on the line. As the boat came out of the water, the force required to pull it diminished. Once up on the foils there were a few problems, so each towing run ended quickly.

The boat’s weight, measured just before launch, was 355 lbs.

The first graph shows the line tension and boat speed vs. time. There are 8 distinct episodes in which the boat is towed, and as […more]

Trifoiler Test – Oct 10

10/11/08

At this stage of tide, seaweed is a problem. We had to stop and clear large quantities from the foil during the test. The boat displayed substantial tendency towards lee helm. Port side J-foil was riding low on port tack and its response seemed a bit erratic. Check helm foot controls. Check shock on port side.