Over the winter I researched Polar programs and found the 20 year old PCSAIL Excel program developed by David Martin at the U of Michigan. It's hard to find the source file online but I did find and download the student version, which only ran on obsolete Excel 2000. I can't find the full non-student version, which is likely not public domain. I've been able to modify and get it running on Excel 2010 with the Solver add-in, and it should work on newer but I haven't had time to test it. I have to say the Excel code and the math nearly made my Engineer head explode. This is Masters or PHD thesis stuff. I made no change to the calculations, so I assume the results are per the original program. I did add Polar plotting capability on an additional tab.
Our 310 is fin keel with the 150 genoa. There are quite a few parameters to enter for the hull and sails. I had to assume some of the dimensions until I was able to get to the boat and measure, but I found that correcting my assumptions didn't make too much difference to the end results. I played with a lot of the parameters and for the most part results were in the same ballpark. I was a bit concerned that the results did exceed theoretical hull speed by a bit. So I do wonder what "student version" means.
The plot for our boat with main and jib is attached. I don't know if appropriate to post the Excel file here, but you can PM me if you want to play with it. This was a good winter obsession, but now we just want to get in the water and sail. Fair winds. /Ed
PS: It snowed 6" today...
