I'm not sure why the race committee would care if one was regenerating. I'm even less sure why one would want to as it would slow the boat.??
Surely, even spinning the prop to cancelling out the drag shouldn't be permitted. Do they really let you do that?
eric SV Meander
---In electricboats@yahoogroups.com, <mike@...> wrote:
Jason,
Check with James to see if you will have RPM numbers when under power? If so that will help you. On my boat when I spin the propeller under sail and I notice that the rpm will continue to rise slowly without moving the AMP draw number off of "0" until I get to about 170rpm. That is telling me that I am pulling so little power that it does not register on the very precise and accurate monitor. If I calculate the forward speed of the 15X12 3 blade prop at that time I will see that I am just about matching the speed of the water column accounting for current and SOG. I gain about 1/4 kts doing this and I attribute it to "eliminating prop drag". If I give the system more power, greater than "0" amps the boat will increase to about 1kts over the first 10amps or 400rpm. I find that I can spin the prop at the most about 550 rpm before I usually impact the sail foil. I will tell you that in our light wind sailing here in Southern California I do this a lot in the summer when not racing because it is more fun to go a little faster and certainly makes tacking a lot easier.
I would be very curious to find out what the racing community would say about the ability of the electric boat to store speed in the form of regenerative power under sail to be used later. I suspect that it would be a very quick NO!
Mike sv Fluke
Electric Yacht of Southern California
Check with James to see if you will have RPM numbers when under power? If so that will help you. On my boat when I spin the propeller under sail and I notice that the rpm will continue to rise slowly without moving the AMP draw number off of "0" until I get to about 170rpm. That is telling me that I am pulling so little power that it does not register on the very precise and accurate monitor. If I calculate the forward speed of the 15X12 3 blade prop at that time I will see that I am just about matching the speed of the water column accounting for current and SOG. I gain about 1/4 kts doing this and I attribute it to "eliminating prop drag". If I give the system more power, greater than "0" amps the boat will increase to about 1kts over the first 10amps or 400rpm. I find that I can spin the prop at the most about 550 rpm before I usually impact the sail foil. I will tell you that in our light wind sailing here in Southern California I do this a lot in the summer when not racing because it is more fun to go a little faster and certainly makes tacking a lot easier.
I would be very curious to find out what the racing community would say about the ability of the electric boat to store speed in the form of regenerative power under sail to be used later. I suspect that it would be a very quick NO!
Mike sv Fluke
Electric Yacht of Southern California
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