What no-one has considered here is that powering calcs are usually done from
the other point of view:

My boat has X lbs of drag at 5 knots, how many horsepower do I need?

Factor in windage (the lee shore situation), foul hulls, appendage drag, prop
efficiency (an oxymoron if ever I saw one) and other such truck like Taylor
Wake Fraction, and you have a real problem on your hands.

Doing it in reverse? Priceless....

Steve

On 17 Sep 2003 02:52:45 GMT, ospam (Stephen Baker)
wrote:

What no-one has considered here is that powering calcs are usually done from
the other point of view:

My boat has X lbs of drag at 5 knots, how many horsepower do I need?

Factor in windage (the lee shore situation), foul hulls, appendage drag, prop
efficiency (an oxymoron if ever I saw one) and other such truck like Taylor
Wake Fraction, and you have a real problem on your hands.

Doing it in reverse? Priceless....

Steve


Once you seize the idea that if a vessel (of any sort) is not
accelerating wrt the water mass, then the total drag = total thrust.

Brian Whatcott Altus OK