Talador
The Savitsky paper was simply to correct your understanding of attached flow, which was clearly wrong.
What you have been saying is essentially nonsense when applied to slender hulls as I have pointed out numerous times. None of the Savitsky information relates to slender hulls.
If the hull is wide enough and slow enough that there is flow over a chine aimed at getting pressure recovery then there is benefit in soft chines to promote attached flow. That is the general principle that the Savitsky paper is referring to. Completely unrelated to my hulls.
My hulls have the aspect ratio of a long thin pencil. There is negligible flow over a chine unless the boat is pitching. In these circumstance the added resistance to pitching that a hard chine offers is beneficial in reducing drag as well. So one of those rare circumstances where it is a win-win.
Rick
On 28/03/2015, at 12:43 PM, "taladorwood@yahoo.com.au [harryproa]" <harryproa@yahoogroups.com.au> wrote:
Rick - "You have not provided any actual drag numbers. The Savitsky information is too general to apply to my hulls."What were you trying to say with the Savitsky PDF then? As far as I can tell the Savitsky information is in total agreement with everything I have been saying.The actual drag numbers depend on the hull shape. How could I possibly provide actual drag numbers on a design that has never been built, nor do I have the specs for?That is your answer to the general observation that hard chines create more drag at displacement speeds? And that a concave stern section creates more drag than a straight or slightly convex stern section?
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Posted by: Rick Willoughby <rickwill@bigpond.net.au>
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