How to cal. Estimated power at the propelleer

Dear all,

Can anyone help me on how to calculate this:

A vsl is 30mtrs in lenght, with froude no of 1.49, wetted surf. Area is 160.54, spd 8kts, frictional rest. Is 67.8, Admiralty coefficient is 383.45. Using this fig. How can I estimate d engine power?

Regards
Mike

 

The power at the propeller is whatever you input on the shaft. The power the propeller can absorb you can get from the manufacturer's charts.

 

Maybe he meant "estimated power needed" to achieve the 8 knots. My guess - tow it and measure the force.

 

Helo Gonzo,

This is a calculation exercise so I wasn't given the details. All the figures are based on assumptions.

Mike

 

Then you need to follow the rules and assumptions of the exercise. For example, do you use 90% of maximum power for calculations?