Bernoulli Effect

[PaulC]

Has anyone come up with any ideas on how to minimise this effect with vents being made the way they are nowadays? I have a problem with sealing the whole thing like a coffin to stop it from happening.
Cheers
Paul

[Miriam C.]

Morning Paul,
Are you trying to increase our vocabulary or are you going to add wings to your new teardrop?

Wake up son, ya been missed and no pictures either.

Some small screened vent at the bottom might help but I am finding it hard to decide how you teardrop is effected????????????

[mikeschn]

Paul,

I'm not sure I understand the problem.

You've obviously got more airflow going over the top of your profile than underneath, so are you saying you have a lift problem.? Are you afraid your teardrop is going to become airborne?

How fast are you towing it?

Mike..

[PaulC]

We have a basic wing profile(very basic) in our TD shape. When air passes over our TD's we in effect have a low pressure area above with a higher air pressure below. The vent I have fitted to my TD allows for constant air flow, even when closed. The resultant Low pressure area above the TD is creating a vacuum effect thru the van. This is resulting in dust and moisture being dragged thru any weak seals. When the TD is stationary I do not have a problem but when we are moving I find that rain is getting in, around the bottom of the doors. I have tried double seals, double latches etc to drag and seal the bottom of the door in.
When I completely seal the vent I no longer have the problem. Do not like that idea.
Any ideas?
Cheers
Paul

[Steve_Cox]

Has anyone come up with any ideas on how to minimise this effect with vents being made the way they are nowadays? I have a problem with sealing the whole thing like a coffin to stop it from happening.
Cheers
Paul

Easy fix Paul. Just slow down to minimise the effect. Velocity is the culprit here

Or the faster you go, the more your vent sucks

[PaulC]

Thanks Steve 60mph is not what I would call rapid transit

Cheers
Paul

[Jiminsav]

I'll tell ya, Paul is right..when I towed the new leprichan up to virginia, the airflow over the roof created a low pressure zone right over the hatch and sucked the canvas off the hatch..and it was glued down around the edges, the only place with no glue was under the hurrican hinge..the canvas was 1 inch under the back lip and the vacuum sucked it out there first and then worked it off till i saw it flapping behind me and went and took it all the way off..one more foot anf i'd of lost it.

[Steve_Cox]

Paul,

I was thinking about putting a spoiler on my TD when I was building it to stop this very thing from creating lift on the back hatch at speed. I wonder if such a deflector closer to the top front radius of your camper would spoil the effect. It would be nice if Mike would go ahead and build a wind tunnel, we have a need to create data.

[mikeschn]

Do you have a 1/12 model we can test?

Mike...

[Jiminsav]

I say let it make the tail lighter...get better milage..

[halfdome, Danny]

Paul, what about putting "J" molding all around the door to channel the water away? I have it from the door handle all the way around to the front of my hinge and I tried to channel the water down near the door but I feel more "J" molding is needed. I need to buy more since I’m planning on continuing it under the door to prevent water being sucked up through the door bottom. Danny

[apratt]

I wonder if you put a couple small vents on the sides would that equalize the air pressure inside, it still don't solve the dust problem.

[Jiminsav]

Paul, to save a lot of gnashing of teeth and pulling of hair, why not just seal the vent when your driving..and open the side window if you absolutely need some fresh air in the tear.

[madjack]

...how about a row of those vortex generators that Andrew is so fond of.................

[Chuck Craven]

Paul

How about a thin plastic cover, put it on the inside to keep any air from going out the vent. Than take it off when parked!

Chuck