You need to refine your model a bit and add the extra drag that the jib gives you. You have a lower aspect ratio sail jib+main than the main alone, and more area of the sail wich is disturbed from the eddies at the ends.
Read your literature (Marchaj, Gentry and others). There is no extra drag due to adding the jib. That is another misconception. Interaction between the jib sail and mainsail results in a situation where the increase in drive is about proportional to the increase in total sail area. The only pay back is found in some lost of pointing angle (but less then you would expect) and in very light laminair winds (winds below 5 knots) where any area far away from the watersurface experiences much higher windspeeds.
Pretty much you are losing yourself in details (eddies, aspect ratio, etc); all these details combined lead to the above macro result.
I have several cases where the M20 uni proved to be faster on the upwind compared to Tornado, M20 sloop and Eagle cat. My examples are based on intervies with Marstrom on different occasions. That proves that your model needs to be refined.
You are a bad scientist Hakan, because the more obvious explanation would be that Goran is a better sailor then the others. Also you are allowing unverifiable data to enter the discussion and to top it off this data comes from interviews with the designer of these M20's himself. We are assured that that unknown Italian Tornado team sailing at that unspecified event are good sailors. We have a few more examples like that, for example that a foiling moth will beat a modern Tornado around the race course. Do you take those at face value ? I certainly don't.
Interestingly enough, all the data that is well know like the Texel data of the last 7 years gets thrown out by you, except for a single (unstable) upwind beat at Texel 2006. I call that cherry picking the data.
I have given you Non-Texel race data in the past on several occasions. You just ignore and forget it, coming back asking for the same data several months c.q. years later. I'm not going to do that again this time. Sorry.
I think it's time for you F16 guys to do some testing. Sail the boat single handed and uni rigged upwind in 15 knots of wind together with a referens F16. Add the jib to the single handed boat and test again.
Were exactly do you think part of my experience comes from ?
I'm not making these things up you know.
I've been sailing my Taipan F16 without a jib for the last 16 months, often doublehanded. This because my jib sail was completely ruined by the sailmaker. Over that time, I've sailed 2-up with just my mainsail against other 2-up F16's as sloops and 2-up F18's. I even got witnesses. Tim Bohan and Gill, you guys remember these rides ?
Every time the result as the same. I could put up a good fight on the upwind legs but they would pass me eventually. On reaches they walk away, not very fast but they do. Under spinnaker the difference (if at all present) is too small to be determined accurately.
In the really strong winds I found that I had to point lower then a sloop rig to keep my speed and VMG up. Pointing high would kill its speed/vmg. All sailing as 2-up. Basically my 15 sq. mtr mainsail was too small to sufficiently power-up even in the strong winds. I ran into the following problem. To get speed I needed drive which I could only get by increasing the angle of attack of my mainsail, so I had the beat off. This powered up the top of my mainsail to much in the gusts lifting me high even when having 150 kg on the wire. Then I flattened the top to calm down the boat as a result I lost some drive but far more importantly I also lost my pointing advantage. I could not break this circle of cause and effect sufficiently to outperform the sloops. Also, forcing a mainsail to operate at larger angles of attack cuts down on its efficiency. Basically it CL (lift) factor goes up with larger angles but its Cd (drag) factor goes up even more leading to significant increases in induced drag.
Basically it felt that I couldn't get the (relatively small) uni-rig to develop enough drive to hold off the sloops. Interestingly enough we were fully powered all the time but this made no difference.
From this I know that adding a jib to an existing mainsail (uni-rig) will improve performance of the boat. At least it does to F16's when sailed 2-up. I fail to see how the results can be difference when sailed 1-up.
All boats named in this post were optimized for 2-up sailing and were sailed that way. My mainsail is cut to suit 150 kg of crew weight. Most often I sailed against Geerts old boat that had an Ullman F16 mainsail that was cut flatter then my Redhead mainsail. His new Blade F16 with the Glaser suit of sails is noticeably faster upwind. The Glaser mainsail has a little more draft to it. We haven't sailed 2-up sloop/uni against eachother yet with his new boat yet.
The numerical model presented earlier appears to be consistent with my own experiences.
How about you doing some testing for yourself.
Wouter
