:?: Project - Delft Series/Hullspeed - Analysis of VO70 hull.

[Jonny88]

Hi all,

For my final year project I am analysing the difference between results gained from the Delft series and Hullspeed for the same "VO70 type" hull.

I have set up a spreadsheet of the Delft formulae and have entered all the data for series 1 through to 7. I've also put in the parameters from Maxsurf for the hull I've designed and have a large table of results for Fr = 0.15 - 0.75, using the formulae found in the International Conference on Innovation in High Performance Sailing Yachts paper: A bare hull resistance prediction method derived from the results of the delft systematic yacht hull series extended to higher speeds. Page 18.

For comparison purposes, series 1 and 2 are of little relevance as they were modelled with appendages so I'm concentrating on series 3-7. Having calculated resistance values for my VO70 type hull, I have come up with some strange values that are OK from Fr= 0.15 to 0.5 but then drop off dramatically after that to negative values and fluctuate around a lot up until Fr= 0.75.

Any ideas? I've checked, double checked and triple checked all calculations and formulas and all seems OK.

Any thoughts are welcome!

Thanks.
J.