In regen the less the pitch the faster the propeller will spin and therefore (rpm x mass) the more energy there will be to extract from that propeller. That is true up to the point of propeller stall. All marine propellers will stall at some speed so the question sort of becomes, "what is the pitch at which a marine propeller stalls in say a 4knt flow?" If one had such a prop then I'd think that near max rpm and therefore good regen could be reliably had at 5knts and on up from there. The higher the pitch the lower the speed at which regen could begin but the energy at 1knt isn't worth sacrificing the higher regen at greater column speeds had by using a lower pitch prop.
In other words a 23x20 will generate more energy than a 23x23 as long as it has not stalled (mostly true). The 23x20 will stall at a lower speed than the 23x23. So in effect, I want to determine somehow what is the minimum pitch that prevents a stall at 4knts. This completely neglects torque of course but i am trying to keep it simple at first.
Does anyone one want to speak to this? Is there any data anywhere?
__._,_.___
.
__,_._,___
No comments:
Post a Comment