Joakim, I'm sure you are right, but since I'm doing all of this just for my own enjoyment, I think I will pursue option 2 a bit further just to...
What I've learned I'll put my head back on the block and attempt to summarize what I've learned from all of this excellent discussion. In...
My 'optimization' is only partially automated. The input defines a series of sail shapes to run at one apparent wind speed and direction. I've...
Let me propose this thought experiment, and see if it can help resolve my conceptual problem. 1) I want to estimate the force created by a sail...
Thanks - Setting an a boundary condition with more wind sheer makes sense and is easy to do. I'm afraid I still do not follow your second point...
Clearly hit a nerve here... Always interesting when new approaches receive such loud criticisms. Rather than defend the Navier-Stokes equations,...
I believe the papers on the subject you are referring to are in the case where you are simulating 2D cross sections of sails at different...
OK - got it. This is the effect of the vertical wind speed gradient on the the apparent wind vs elevation. And yes, that is included in the model....
Perhaps you are thinking of a different frame of reference? In this model the boat is fixed in the center of the grid and the airflow moves by it....
This model simulates a 100m x 100m x 50m high box of air with the 10m boat in the center. Drag from the water surface results in a wind speed...
Thanks for your thoughtful reply. As you say, this 'optimization' takes the sails to places that I can't really go with my own boat with real...
I have been experimenting with using a 3D OpenFOAM CFD model to 'optimize' sail trim. The test case is a J/32 fractional sloop. The CFD model has...
pictures of top and bottom vortexes Here are a couple of views of both vortexes from a CFD simulation. It is clearly going to depend on the boat...
It still looks to me that the winglets are on the wrong end of the sail. The big vortex is at the foot, not the head of the sail. When I get time...
I think the shore station is probably best, unless you went with an acoustic/doppler wind speed/direction instrument. Any small mechanical...
Update on procedure to collect sailing data What I'm finding is that you need a period of 4-5 minutes with one sail trim and one wind angle to...
If you have not already, take a look at the parallel forum under www.cfd-online.com. I am not an Ansys user, but in general you will need STL...
How big is your model? I ask because things get very different below about 1 meter. The boat ends up in a surface region with a large wind speed...
Knot meter bias One of the first things to pop out of the data is how far off the knot meter gets once the boat is heeled. The plot shows two...
It is just a hobby for me too. I did CFD for work before I retired, but applying it to sailing is much more fun. I've read that CFD played a...
