- #1
Yamaharacerx
- 8
- 0
So I go into a debate this morning with a co-worker about a boat hull design.
He is stating that if we create tunnels in the bottom of the boat that run longitudinally and are capped on the bottom but open on the ends they will trap water and act like ballast tanks thus adding stability when the boat heels. My argument is that since the water is not trapped like a typical ballast tank the water will just move out of the back of the tunnels as the boat heels, and that the water inside the tunnels cannot be considered trapped because the tunnels are open on the ends, thus allowing equalized pressure in the tunnels as the boat heels. I would think that you will see a slight resistance in the boats heeling acceleration because you have more surface area interacting with the water but since you are not containing the water within the hull by leaving the ends open I would not believe it would do the same as having a ballast tank inside the hull at approx. the same location.
One last note this argument only exists when the tunnels are under the waterline.
I drew two different pictures. One showing a standard boat hull and one with the tunnels. The argument is not about when the boat is running in a straight line but when the boat is standing still and just heeling from side to side.
I am hoping someone can explain to me the physics of what is happening to that water inside the tunnels. And if I am looking at it from the wrong point of view.
Thank you
He is stating that if we create tunnels in the bottom of the boat that run longitudinally and are capped on the bottom but open on the ends they will trap water and act like ballast tanks thus adding stability when the boat heels. My argument is that since the water is not trapped like a typical ballast tank the water will just move out of the back of the tunnels as the boat heels, and that the water inside the tunnels cannot be considered trapped because the tunnels are open on the ends, thus allowing equalized pressure in the tunnels as the boat heels. I would think that you will see a slight resistance in the boats heeling acceleration because you have more surface area interacting with the water but since you are not containing the water within the hull by leaving the ends open I would not believe it would do the same as having a ballast tank inside the hull at approx. the same location.
One last note this argument only exists when the tunnels are under the waterline.
I drew two different pictures. One showing a standard boat hull and one with the tunnels. The argument is not about when the boat is running in a straight line but when the boat is standing still and just heeling from side to side.
I am hoping someone can explain to me the physics of what is happening to that water inside the tunnels. And if I am looking at it from the wrong point of view.
Thank you