Saturday, July 2, 2016

[Electric Boats] Re: Electric Sidewheeler [2 Attachments]

 
[Attachment(s) from danbollinger included below]

The shorter the boat, the more advantageous sidewheels become. That's because small boats pitch a lot and that changes the depth of sternwheel floats (paddles). The is negligible when the wheels are mounted at the pitch axis. Although, roll then becomes a problem, but less so.


The electric_motor/hydraulic_pump/hydraulic_motor is a bad idea efficiency-wise. You will lose a lot of power and range. Better to just go direct. Since the paddle wheels are so large, you probably can't direct drive them with even the Ecycle hub, but check the specs to confirm this. If not, then use a cogged belt arrangement. I prefer the Goodyear Eagle herringbone system. It is quieter and self-centering. Make sure you have some sort of mechanism to adjust the wheel depth. You'll need to adjust this for trim as your displacement changes. It could be hand cranks, or better yet, DC linear actuators.

The other great advantage to using sidewheels is that they can be feathered. The feathering mechanism insures that the floats are vertical when immersed. Essentially, a wheel performs as if it was a much larger diameter. What this means is that the thrust vector is aft. Without feathering, the floats have a down-angle thrust vector when they enter the water and a up-angle vector when they exit. You can imagine the rooster tail, which of course is a waste of energy. Feathering is more valuable as your wheels get smaller. I've attached a drawing of the mechanism.

I've also attached a test rig I made for a small boat sternwheel that I designed a feathering mechanism for. And they said it couldn't be done!





__._,_.___

Attachment(s) from danbollinger | View attachments on the web

2 of 2 Photo(s)

Reply via web post Reply to sender Reply to group Start a New Topic Messages in this topic (14)

Check out the automatic photo album with 2 photo(s) from this topic.
Paddlewheel.jpg f87p272.gif

Have you tried the highest rated email app?
With 4.5 stars in iTunes, the Yahoo Mail app is the highest rated email app on the market. What are you waiting for? Now you can access all your inboxes (Gmail, Outlook, AOL and more) in one place. Never delete an email again with 1000GB of free cloud storage.


.

__,_._,___

No comments:

Post a Comment