T&T: Hull Speed 20% faster and more economical, by new

[bill]

Arild wrote; 

"After much research it was discovered the flexible hull frames created a 
shallow convex tunnel along the keel timber. This tunnel trapped  sea 
foam and air bubbles under the hull and effectively reduced hull skin 
friction. 
At least that was the explanation  developed to explain the observed 
fact  of  faster than  predicted hull  speeds."

His comment was regarding viking ship replicas.

I'd suggest the lapstake planked hull would have a major effect in flow separation.  Whilst lovely and fair when done properly, the laps don't necessarily or always follow flow lines and will create interference with laminar flow and introduce air, lessening surface tension allowing the hull to break free and exceed theoretical hull speed when enough power is applied or surfing conditions exist.


regards,
Bill