Kiteboat Tests

Kitefoiler Tow Test Three

1/26/11

We took the Kitefoiler out again today to see how it performed after we had fixed the rubbing issue from yesterday. The boat consistently foiled on the starboard side, but required much more manual adjustment to foil on the port side. This suggested that the foils were asymmetrical, which we later verified through measurement. We also learned that the actual pivot point location was not where we expected it to be, which was preventing the sensors from controlling the J-foil angle of attack, as intended. We shaved some material off the J-foil extensions to address this issue and hope to see better results tomorrow.

The force required to pull the kitefoiler were a bit higher in these tests due to […more]

Kitefoiler Tow Test Two

1/25/11

Today we performed a second tow test of the new kitefoiler. Some minor repairs had been made since the last test, the sensors and foils were adjusted, and the tiller was strengthened. The boat now weighs in at 390 lbs, which is a larger increase than expected. It is possible that we under-measured the kitefoiler weight before the first test.

This time Don manned the helm. We were able to get the boat more stably onto its foils, especially after Dudu and Joe began to adjust the foil angles manually. We found that there was interference from the bottom of the cassette fairing. We will make a mod in the morning and be back out there tow testing first thing.

[…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]

K1 test – Jan 18

1/18/11

We took K1 out today to try to test the version 4 V-foil and the removable starboard keelfoil. The wind was very light, so kite time was brief, and we did not go fast enough to get the boat foiling.’

Kai View Data:
20110118-k1-vFoil4.kai.bz2

Kitefoiler in Maui

3/5/10

Don Montague and Joe Brock Jumping waves in Maui on the kiting Trifoiler! 16 sqm kite.

Helicopter footage by Darrell Wong and Roland Chen. Boat and kite cameras by Don and Joe. Helicopter Pilot: Don Shear. Video edit  by Andrea Dunlap. Music by Yung Sir.

Quadfoiler and Stiletto tow test – Jan 14

1/14/09

We towed Quadfoiler and Stiletto with a 35 foot protector RIB.

Quadfoiler and Stiletto, Speed vs. Load Comparison
We instrumented the Quadfoiler and Stiletto boats with a GPS receiver and towed them with a line attached to a load cell. Each boat was first towed directly behind the power boat, then towed while steering so the towed boat was 30-45 degrees away from the center of the wake. The length of the tow line was approximately 40 meters. The plots below show speed vs. load for each towed boat. The red points indicate periods during which the test boat was being pulled directly behind the power boat, while the green points show data recorded while the test boat was […more]

Quadfoiler Test – Oct 11

10/12/08

After removing unnecessary ballast water (drain plug error), the boat performed normally. Typical speeds were attained and the occasional ‘spin out’ was still noted. Today Joe took control of the kite and was able to achieve ‘foil borne’ status with Don at the helm.

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.