2021-01-22, 03:16 AM
(2021-01-21, 03:43 AM)seandepagnier Wrote: Previous Reply slice; "My point is, the ultrasonic anemometer discussed for $139 is clearly designed intended to be mounted vertical. It is not designed to take wind from an angle. So if the boat is heeling, the wind will flow through the sense area at an angle which creates much turbulence and it is doubtful that the readings will be accurate."
Understood. For competition and autopilots, speed & accuracy are the driving Design Goals
I read-up on some tests, since I have no data of my own, even from prototypes.
Referencing Practical Sailor; https://www.practical-sailor.com/marine-...ensor-test
(yes, i agree their "science" is not laboratory grade)
And that report is dated 2015
They claim the Matreon and Airmar can be "accurate' with a 45 degree heel
They also said (agreeing) that Racers prefer cup/vane for accuracy & response, but Cruisers and others would prefer the no-moving parts and bird-resistant features of the ultrasonic approach.
I think your (good) point of turbulence is due to the two-plates design, when the wind is not coming through the slot smoothly?
Do you think the "claw" type design (pic) may be less prone to turbulence?
i was thinking that with an angle sensor (MeMs IMU) the software might be able to compensate for tilt effects.... to some level that needs experimental data.
The ESP8266 is wicked-fast, so a bit of calculus and look-up tables is possible too.
PS: I 3D printed some anemometer cups too, along with many Boat CAD projects; 3D printing Rocks !
I even used some Ninjaflex for water pump gaskets; its water & diesel proof!