Venting a tunnel

[JimW]

There isn't much benefit to making it so complicated. A simple through-hull fitting and flexible hose does the job. There is also not much benefit to putting a valve on it. I've had it both ways, and I found that I never closed the valve.

T

The value of the valve is pure science, (limiting the variables in an experiment to one). PVC ball valves are cheap and easy to install.
The value of the baffle box is from the post that says something about soaking a leg when deccelerating.
It also allows a "slit" opening to the vent instead of a circle in the middle. Probably not needed but why not? This keeps the tunnel surface "clean" and will give a clearer result of vented and unvented performance.

If we're going to do an experiment, lets make sure it teaches us as much as possible within reason.

Just throwing out ideas in case some one wants to explore.

I enjoyed small details on my build that I could work on on the bench for a while instead of inside the hull stumbling around, knocking the box fan over, etc. Sprending a couple days building a vent baffle box and the fittings would be a fun break for some.

[timoub007]

Not knocking the idea Jim, just telling you I've been there and done that. The baffle idea is likely from me, but if you make the hose long enough it is really not needed. The water will only "burp" or "puke" up so much before it expends the energy/pressure from the hull coming off plane. If your hose is longer or above this elevation the water will not exit the hose.

Have fun with it and post pictures. I enjoy seeing others' take on my ideas.

T

[pedroe]

The vacuum in the tunnel does not pull the boat down or up. It affects how much water is sucked up into the tunnel ...

Fisics law: "For each action there is a reaction"

If the boat sucks the water up, the water will suck the boat down

[Cracker Larry]

I like hanging around smart people

[gstanfield]

Umm, isn't it spelled "physics"

The last post was two years ago too Although the physics comment is correct (Newton's third law)

(intended in good humor, not as a criticism)

[pedroe]

Umm, isn't it spelled "physics"

The last post was two years ago too Although the physics comment is correct (Newton's third law)

(intended in good humor, not as a criticism)

I hope that you portuguese be better then my english. Sorry my mistake

[gstanfield]

I'm sure it isn't I don't speak portuguese at all, never been to Brazil or anywhere else that may speak it. I was just giving you a hard time friend so don't take offense

By the way, welcome to the board

[Cracker Larry]

I don't speak portuguese at all, never been to Brazil

How about Portugal?

Fisics law:

Umm, isn't it spelled "physics

It was phonetically correct, I understood, works for me George, ya got to realize that every one don't live in Wyoming This is an International group. Peter is kind enough not to point out my many errors in Papiamentu, Spanish and Creole that I struggle with The idea of conversation is to transfer thoughts, ideas and understanding, not to spell all the words correctly in a foreign language Everywhere is foreign to somebody

I hope that you portuguese be better then my english. Sorry my mistake

No mistake Welcome. I'm sure that your English is better than my Portuguese. Hell, it's probably better than my English

[gstanfield]

yeah, portugal too I just think brazil for some reason as they speak it down there and some friends of mine are in Brazil a lot of I know they speak the launguage. I know that not everyone is from Wyoming, Hell I'm not from Wyoming I'm just temporarily detained here That's why I posted the tag line that it was meant in good humor and not as criticism. I guess I figured that would work

(intended in good humor, not as a criticism)

I guess I'm used to being around folks I can joke with

[Cracker Larry]

I'm joking with you, but don't want to scare off our new friends. It's all good