Academic resources for ground effect

[KaneTheMediocr]

I've found lots of nebulous hand-wavey explanations for the ground effect on the web, but never any serious academic work explaining the effect, or with rigorous experimental data. I'm doing some experiments regarding the effect of various obstacles to airflow on thrust, and need some references for (eventually) a paper.

Does anyone know where to find this? Google has, so far, failed me in this regard (yes, I tried Google Scholar as well. Most of the papers I found clearly weren't what I was looking for, those that might have been too a week to get a hold of to determine that they also were not what I was looking for).

Anyways, if anyone here has been in a similar predicament and met success, pointing me to a good paper (or even a good website) would be very helpful.

[Steve Guinn]

There are some references at the bottom of this article...
http://en.wikipedia.org/wiki/Ekranoplan

[LareeRudee]

I've found lots of nebulous hand-wavey explanations for the ground effect on the web, but never any serious academic work explaining the effect, or with rigorous experimental data. I'm doing some experiments regarding the effect of various obstacles to airflow on thrust, and need some references for (eventually) a paper.

Does anyone know where to find this? Google has, so far, failed me in this regard (yes, I tried Google Scholar as well. Most of the papers I found clearly weren't what I was looking for, those that might have been too a week to get a hold of to determine that they also were not what I was looking for).

Anyways, if anyone here has been in a similar predicament and met success, pointing me to a good paper (or even a good website) would be very helpful.

I got over 900 hits with this search:

qqqqqqqq

"ground effect" physics "fluid mechanics" OR "fluid dynamics"

qqqqqqqqq

and.

over 3,000 with this one:

qqqqqqqqq

"ground effect" physics

qqqqqqqq

and almost 4,000 with this:

qqqqq

"ground effect" explanation OR explained

qqqq

If I had more time, I'd study this RIGHT ALONG WITH YOU.....

Good luck,

LarryR : )

[LareeRudee]

I couldn't resist these:

qqqq

over 11,000
"ground effect" aerodynamics

qqqqqq

over 5,000
"ground effect" "air flow" OR airfoil

xxxxxxxx

LarryR : )

[nmasters]

The WIG page (http://www.se-technology.com/wig/index.php) has always had an accurate description of ground effect with references. Pic <What is a WIG> from the main menu, then <Aerodynamics>. Don't know why you couldn't find it it's the first page after the product search when I google for wig ground effect (http://www.google.com/search?hl=en&safe=off&q=wig+%22ground+effect%22&btnG=Search)

[KaneTheMediocr]

I did find the WIG page, and it wasn't what I'm looking for. I don't plan on shelling out cash for a membership just to search their database that MIGHT have resources for me, and their explanation (although it is probably correct) lacks the mathematical rigor I was looking for.

For the record, I haven't had problems getting google hits, I've had problems getting USEFUL google hits. Most of what I have found is the same vague "cushion of high pressure air" stuff (if its related to the ground effect at all) thats on the WIG page, and I was looking for some sort of quantitative data, or at least an equation to wave at my professors.

[N9DP]

It’s not clear to me if you mean ground effect in the sense of the anomalous lift experienced within a fractional wing span of ground, or turbulence effects due to wind flow over proximate objects. In either case, Google and the Internet are not the resources for serious academic research beyond “simple hand waving”.

I’d be interested in a little background:

What exactly is your assignment?
What is the course – intro to aeronautical engineering, general science, fluid mechanics, . . . ?
What is the level – undergraduate, graduate?
What school?

I’d be very surprised if you could find anything beyond the simple hand waving explanations Google provides. Journal articles are not normally provided free of cost to non-subscribers. There are a number of textbooks, quite advanced in their scope, that treat the areas you are addressing. Access to them is through a library, not the Internet.

Good luck in your studies,

Dennis

[KaneTheMediocr]

My interest was regarding the anomalous lift within a fractional wing span of ground.

My assignment is blessedly ambiguous, I am doing an independent study titled "Unmanned Aircraft Design", but my main goal for the first term is to examine how thrust changes near boundaries. I already have an experimental rig to test this, which will be the data I'll use when I try to get something flying, but before I do that I'll be giving a presentation on what I've found. That presentation will be very awkward without any knowledge of the established theory regarding the ground effect.

This is a "senior project" of sorts for me, and I'm in an undergraduate physics program at a small liberal arts school with no engineering.

So, although I have ILL options, the amount of literature on the topic at my library is scant, and I'd rather not order a whole bunch of textbooks over here in the hopes that one will have what I need. If you know a particularly good one, please let me know about it.

Thanks for the input.

[N9DP]

“Foundations of Aerodynamics” by Kuethe and Chow, ISBN 0-471-12919-4, pp 117-119 and 207-210 discusses ground effect with appropriate mathematical rigor. Ask your school librarian to get those pages copied for you from another library. That’s what she’s paid those big bucks for.

Your project reminds me of an undergraduate lab experiment my lab partner and I did in 1961. We were both fanatics about motorcycle hill climbing and were known to at times secretly work on our engines in the Physics machine shops. In E&M lab we measured the properties of a Ducati’s cam-driven breaker point ignition system at high rpms, and had oscillograms illustrating point bounce. We thought it was A+ work. Our prof gave us a C, with a caustic comment “What’s the Physics in this, anyway!”

Ever since I have been applying Physics to my hobbies, and it really applies to RC electric models.

Dennis

[nmasters]

http://ntrs.nasa.gov/search.jsp

[KaneTheMediocr]

Thanks a lot N9DP, I'll try to get a hold of that. Some physicists don't like when you actually USE physics (a task for mere engineers) rather than just talk about it--theres a grognard much like your prof in my department, but my advisor is pretty supportive of this even though its not really his field (or even department).

And NM, I'll look at that too. tx all

[nmasters]

From “Tailless Aircraft in Theory and Practice” by Nickel and Wohlfahrt.

No, I haven't been looking for it all this time, I just happened to run across it


Oops, forgot to rotate the Wieselsberger ref :o

[LareeRudee]

From “Tailless Aircraft in Theory and Practice” by Nickel and Wohlfahrt.
No, I haven't been looking for it all this time, I just happened to run across it
Oops, forgot to rotate the Wieselsberger ref :o

Just an interested observer, but that is interesting; just wish it was LONGER.... if you find anything else, post it........ if it IS too long, it'll just hafta wait until I REALLY retire, but for now, I enjoy it.

thx,

LarryR : )