Optimizing Air Pressure for Hovering: Calculating the PSI Needed for Static Lift

[c2it4u532]

I want to create lift of an object about the size of 36 in by 8 in. the lift would be provided by
compressed air and the object would have an air dam and skirt (like hovercraft) and lift approx
250 lb mass on it to floatation level of .05 in (where skirt would not reach above lift surface.
What type of psi would it take to constant hover. Assume Skirted area is approx. the area of
the underside of the object. If air pressure underneath equals mass of object doesn't buoyancy
occur?

 

[Danger]

Welcome to PF.
I finally found this calculator that Russ linked to a couple of years ago. Perhaps it will be of help to you.
http://hovercrafthomepage.blogspot.ca/p/hovercraft-design-calculator.html

 

[c2it4u532]

Its not a tennis court and its not a game. I need some assist in calculating some issues.
Itought I had the numbers to start and and wondering if these values are right. IF you have heard of Kickstarter.com , then you or a few of your associates might understand. I am not going back to school to learn values and then make other people very prosperous for sharing ideas. To your benefit and mine. Thanks for the input. your reply appreciated.

 

[Danger]

Its not a tennis court and its not a game. I need some assist in calculating some issues.
Itought I had the numbers to start and and wondering if these values are right. IF you have heard of Kickstarter.com , then you or a few of your associates might understand. I am not going back to school to learn values and then make other people very prosperous for sharing ideas. To your benefit and mine. Thanks for the input. your reply appreciated.

If that's your attitude, you're in the wrong place. Most of the teachers here are world-class experts in their fields. (I'm not one of those, but anyone that I cite is.) One of my loves is hovercraft, and Russ was kind enough to find that calculator site. If you don't appreciate that, then I don't want to have any further contact with you. And the quote about the tennis court is my signature that is included automatically in everything that I post. It has nothing to do with you.

edit: By the bye, you don't demand things here; you request them or hit the road.
Also, why should we help you to make money that you have specifically stated we will have no share of?

2nd edit: Even if we help you, Greg will own the patent since it will be designed on his site and he owns all rights to it.

 

[c2it4u532]

I apologize if I offended you and my intentions were not in that direction. I am not demanding anything.

 

[Danger]

Accepted on my behalf. Perhaps it was a communications misunderstanding, and I over-responded.

 

[CWatters]

I don't understand what you mean by "the skirt would not reach above lift surface"? Is there a gap at the bottom of the skirt or does the skirt form an air tight seal with the "ground"?

If there is a perfect seal the required pressure is easy to calculate..

It's just 250/(36x8)= 0.87psi above atmospheric.

If there is gap/air leak the required pressure is the same but you need to calculate the flow rate required which is beyond my experience.

 

[CWatters]

If it's on water the same rules on displacement occur. eg a hovercraft displaces water equal to it's mass just like a boat.