Here the wave-making drag (form drag)for the conditions in which the C-class races

Quote

You say that “ at these low speeds the drag from the hulls is almost entirely created by wetted surface drag” wheras the Miss Nylex data you present shows that there is a 60/40 split.



Correct, that is why I wrote in the preceding sentence :"... for the conditions in which the C-class races ..." These speeds are above the Froude law based max. hulls speed number. The article names speeds around 10 knots (6 - 14 knots). This speed is the one that is most encountered along the track even when higher speeds are achieved on smaller sections.


Quote

At 6 knots the split would be the other way around 40/60 with wave drag taking the higher percentage of drag. Surely the Miss Nylex numbers back up what I am saying.


No Grob, this is completely wrong and most fundamentally flawed scientifically. Wave-making drag INCREASES when the hull speed is lowered ? While the wetted surface drag decreases ?

I'm not going to explain away all nonsense arguments that are put forward. I'm truly sorry.


Quote

I am saying that the wave drag has a big influence on total hull drag but changing from 5m to 5.5m length only is not enough of a change to affect the wave drag by much. A thinner longer hull is always better but reducing displacement is the real key.


Now were are back at the "always" rules again. Ahh well, I've explained my side. Whether other people believe or not is up to them.

Best of luck Grob,

Wouter

Last edited by Wouter; 12/13/06 01:46 PM.
Wouter Hijink
Formula 16 NED 243 (one-off; homebuild)
The Netherlands