I''ve worked my way through Andy Lennon''s book R/C Model Airplane Design and currently reading the classic by Martin Simons, Model Aircraft Aerodynamics. My question is what''s the next book for a model aerodynamics enthusiast and hopeful designer. I''ve heard Abbott''s book, Theory of Wing Sections is pretty informative. Simons mentions a couple of interesting sounding works by H.L. Chevalier (Challenge Engineering?) in his book''s appendix but I''ve yet to come across them. Any other good stuff out there? (I understand calculus etc. and have an ME degree..)

EDIT: I am so impressed with Martin Simons book I have to give it a better plug! Here's the review I wrote for Amazon:

Don't judge this book by it's lightweight looking cover like I once did. This book is a CLASSIC filled with 100's of pages of important information for understanding aerodynamics in general and improving your model aircraft. Simons has a gift for conveying all of this knowledge without resorting to mind-numbing mathematics, instead relying on vector graphics and charts so that all can follow along. I am now reading the book for a second time highlighting important bits as I go! It's a great value for anyone wanting to design or just learn more about their R/C hobby. There are even chapters on the dynamics of propellers and helicopters. Appendix 1 contains all the salient calculations necessary to design a plane from scratch. Appendix 2 has some experimental data on airfoils. Appendix 3 has hundreds of airfoils and laminar bodies from many different sources. Publishers: please add more polar data to appendix 2 and replace that cheesy cover with something more appropriate in the next edition.

Abbott and von Doenhoff's book is actually a somewhat focused book. It basically works over the NACA profiles in detail. Before doing so, it does run through a lot of theory and hits on a bunch of experimental findings.

No way is it a book for the masses. You will make use of your engineering training for sure. It's heavy on the equations but also the charts and graphs.

Theory of Wing Sections was originally published in 1949. No, I didn't buy it new then, but I did pay $5 for a brand new 2nd edition. It is a paperback, after all.

It's almost 700 pages, but slightly more than half is appendix most of that devoted to the profiles. One of the best uses I've made is the list of references. There are a lot that included descriptions of the NACA reports themselves. It can save you a bit of effort selecting ones worth purchasing. That is, if they're still available. Haven't wanted any in years.

I remember seeing and taking out "Theory of Wing Sections" from our bigger main library many years ago. It was more to try to pick up on some sort of general understanding rather than hack through the math. For that purpose there were about 15 to 20 pages that helped. From there it was full on jumping into the deep end armed with a slide ruler. Yes it was THAT long ago. I was a teenager without the math knowledge to understand more than a tiny handful of the math.

If you go that deep into this I'd also recomend tempering what it teaches with reading the prep work that Michel Selig did in getting ready for his first big wind tunnel work. There is a lot of good information in there about the differences in airfoil shapes for lower reynolds numbers such as we use. That transition may also help you to understand why for super low speed airfoils such as free flight and indoor that the airfoils of choice get increasingly thinner and why an arced flat plate is the best choice for extreme and stupidly slow flight.

It's also interesting to see the shift away from mathematically designed airfoils such as the NACA stuff and the use of pressure distribution analysis as used in Xfoil where the shape means little as long as it provides a suitable pressure distribution.

Glad to see your comments on the airfoils
Being a firm believer in "you can't beat actual experience " I stopped tryng to wade thru the airfoil selections years ago --when I saw there was very little correlation with the models I was using and some proven , common airfoils
When I got into absolutely FLAT plates and still had guys trying to tell me some "airfoil" would work better I decided I was into areas not really explored thoroughly in PAST books .
which made sense, as the flat plate - high power super low wing loading -simply never existed 5 years ago.
This experience was a golden treat for me as I quickly got to see how much the teaching of many years experience actually relate to current, NEW model technology
some does (of course)
some - well does not. It isn't that the rulesof flight have changed- it is just that the new stuf explores different parameters.



Edited to remove off topic material.... -BCM

And back to the subject of books.........

As BMatthews says, there are pages in the Theory of Wing Sections that are quite instructive. I found that the math wasn't actually of much value to me, but the general presentation was very worthwhile. There is a section on the Theory of Thin Wing Sections for example. It's quite interesting to note how much is actually known even if it's not showing up on C5Bs or F-22s nowadays.

What is of unique value from this book are the many charts that compared actual test results versus the theoretical predictions. But sections like the High Lift Devices section were the most useful. The book seems to document a lot of the low speed research being done at the time. And that means it covers a lot of what we're interested in right now. The numbers and equations really aren't of much value, but the comparisons and relationships certainly are valid. And a lot of that information is shown in charts.

It'd be worth having.

Theory of wing sections, or a large part of it, is available online from NASA/NACA web site as NACA TR 824. The link below might get you there.

http://hdl.handle.net/2060/19930090976

To the original poster, read books from Selig or go to Martin Hepperle's site. These guys know what they're talking about, especially when it comes to model aircraft airfoils. These guys have the analysis to back them up.

Baker



edit........ the topic is "Good Reading" and is about books on aeronautics.

I KNEW I would get this type of a reply from at least one reader
No -- all the guys you mentioned did good work -and lots of good info is out there that they made available
I have probably built more models than you can count.
You don't fly any flat plate stuff? and think I am full of crap
again
fine with me
some day you may take a step into the flat plate stuff and find out how it works and which applications for it are both effective and practical.
I really get tired of such smug and meaningless replies.



I could care less.

before I leave this site -for good
I have had a number of guys ask whre I got the info for building the performance models I have (which have flat wings )-
I tell em there apparantly is no published info on these models
Each time I bring it up - I get nothing but ridicule here and advice to read books which do not apply.
In total disgust - I am as they say, gone.

Dick, please stick around. Those of us who know you respect your input. There's book learning and there's practical experience. I'll go with the latter in the final analysis every time.

That's from practical experience too.

I appreciate everyone''s input here. I made an Amazon purchase last night. I bought Wing Sections by Abbott and Theory of Flight by von Mises. I considered Elements of Airfoil and Airscrew Theory by Glauert thinking it might have a bit more discussion on prop theory but ultimately reasoned von Mises had it covered and was cheaper.

I don''t want anyone to think all I do is sit around and read books. I currently am flying a Bridi Kaos and working on a "scratch built from plans" Duelist Twin in the Kit Building forum where I am making good progress and have had some thoughtful input along the way:[link]http://www.rcuniverse.com/forum/m_7165436/tm.htm[/link]. I have begun working with Profili 2 and XFOIL. My ultimate goal is to be able to design my own aerobatic and scale r/c planes.

Balsa, foam and many composite materials are very inexpensive in commodity form and make for rapid prototypes. I''m having a ball tinkering in this hobby.

EDIT: Regarding Abbott, see my comments on post 23. I don''t recommend it as a reference for model designers.

BTW, if you're looking for something fun to read...............

You will get a kick out of this one, if you can find it.

It's one of the first "scientific" books on model airplanes that was available and affordable. The author was born in 1885 if that gives you a clue. It was actually published in 1955, just a year before he died. I think I paid $1.75 for it new. I would have had to pay full price. And tax would have been 2% at that time.

You will get a look at modeling when it was young. It's basically about free flight and control line, which were pretty much where modeling was at back then. But a bunch of it is actually useful. And it's like almost all books on aero, some of it's not directly useful, but some of it is. Interestingly enough, there is a fair amount in it about flat plate airfoils.

Crate,

Recently, I ordered this book from Amazon: Fundamentals of Aerodynamics by John D. Anderson. GREAT BOOK and matches your math background and degree. With a EE degree, I have no problems with the book.

Frank's book was one of the first studies along with Circular Airflow that actually paid much attention to model sized aerodynamics and seriously looked at the world we free flighters and slower RC modelers fly in. His study of the forces and trimming requirements for a high powered free flight model was legendary stuff and is still required reading for any power free flight flyer that isn't all wound up in clockwork trim tabs.

He's also one of the first to seriously look at the curved flat plate airfoils used for indoor modelling.

It's one of those situations where us modellers had to fend for ourselves and as such I think it should be required reading for anyone that ventures into wingspans of under 5 feet and especially for folks looking at parkflyers and the like.

For example he showed that at "our" reynolds numbers the stall occurs at a far lower angle of attack than for full sized aircraft.

ROCK, That book by Hoffman looks rare as chicken teeth! Where did you find it?

PRGONZALEZ, I was seriously considering Fundamentals by Anderson especially after I discovered several India-based book dealers are selling the "International" version (black & white, paperback) on theBay for $30 shipped! That's a great deal for a brand new 1000 page textbook! I'll probably buy it after I get through the two I just bought.

Off-topic: $160 vs. $10 just makes me cringe at how publishers like McGraw-Hill, Wiley, Houghton/Mifflin are still totally abusing the American college student. It was a problem 40 years ago and now its even worse!

Crate,

I didn't pay the full price. I bought it used in excellent condition. Yes, I paid a little more than $100.00. But, the book looks new to me.

I have gone through the chapter that discusses airfoil shapes and their lift and stall characteristics. I wanted to understand the snappy characteristics of some aerobatic airplanes. In my particular case a NACA wing and the stall characteristics for 10%-15% airfoils. I had a Giles that I lost on landing approach. I always wondered what I did wrong. The model just flipped over to one side and hit the ground. So, I started to study the problem to try again.

Last year, I built another plane of the same model, this time with better understanding of the whole picture. I am still working on setting up the model correctly. So far, the model does not snap at all. I can do tight turns and pull on the elevator hard like any other sports plane with thicker airfoil with no problems.

The second incentive I had to buy the book was my 14-yr. son. He is wondering if he wants to study aerospace design engineering. So, I wanted to show him the level of math he has to go through and the kind of stuff he would be studying. He is at 9th grade taking 10th grade advanced placement math and he is acing the class with ease.

PR,
What did you do to improve the low speed performance of the Giles? I have a .40 size plane that I have to land like a rocket or it gets all loosy goosey on final(51" span, 10.5"chord, 14% semi).

Nice to hear your son has an interest in engineering. Thats quite remarkable these days with so much negativity toward it in American pop culture: style-retards, nerds, etc. I figured the younger crowd all want to do "mergers and acquisitions" or "CSI-SVU" or something.

Stick around Dick, the rest of us might learn something.

Actually, the airfoil is only about 5% or less of an airplane design. They have been studied to death, and yet have far less to do with the overall performance than almost anything else.

Crate,

One of the most important things I found is that symmetrical airfoils between 10%-15% experience high-speed stall at around 15-degrees AOA. At 15-degrees and more, the airflow detaches from the upper wing surface and there is no more lift. We cannot prevent that. We have to work with it.

The first thing I did was keep a low or acceptable wing-load. Second, locate the CG properly. Third, setup elevator throws. I keep my wing-load at around 25. I was really shooting for 23 but I could not accomplish it using the top-end engine. I setup the CG so the nose of the airplane does not climb or dive while banking and I setup the elevator to operate just below 15-degrees AOA. This does not mean the airplane is not able to do a tight turn of 180-degrees in a small radius. So, the way I understand it, the wings have to be at less that 15-degrees AOA to keep flying while the airplane as a whole is very responsive because of the way the CG is located. Does it make sense? Think about the gradient or rate of change of AOA over wing flow. Keep the gradient low. It is all aerodynamics.

Send me a PM if you want to go over the setup with you.

Pedro

BTW, guys, if you are on a limited budget, let me suggest that you do NOT include that little book "Model Aeronautics Made Painless". That little orange paperback really isn't much more than a historical curiosity. It's basically a scrapbook by the author. And a fair amount of it is poorly ordered, most is not explained, and some of the explanations are awful.

Another book to save money on by passing over is "Stick and Rudder". It's EXTREMELY narrow and seems to really have only two points. They're good points, but how many times do you need to read that stalls are the result of excessive AOA. And he goes to enormous lengths to convince the reader that the rudder is of no use. He also is stuck in his present, which is our past. It's actually amazing how much space he's devoted to the same lesson over and over and over again. He could have produced a pamphlet and covered his points. He apparently was a flight instructor in the 30s-40s. But lord, his students must have been dumber than bricks and slower than paint drying. And his point about ailerons causing adverse yaw was already being cured when he wrote the book. It's not about aerodynamics so keep that in mind if that's what you're looking for. It's actually a primer for anyone learning to fly who will be using a 1930s trainer. It was worth it to me for what it cost, less than a paperback at today's prices. But it isn't on the top of the list of aero books for sure.

Anyone ever hear of this guy H. L. Chevalier or his publications:Model Airplane Design and Performance, Model Airplane Propellers Selection and Performance?

DaRock, I hear ya about Stick and Rudder. I think it was meant as a "practical guide book" for seat-of-the-pants pilots back in the '40s/'50s when civil aviation was exploding after the war and far more accessible financially than today. My own flying instructor in the early '90s went on about the book to such an extent I picked up a copy. I just now found it in my aviation section with a marker at page 97 so I guess I only made it a quarter way through before tiring of it. Most of his discussion is on obvious concepts like visual perspective, relative motion, etc. It has some just plain silly topics like diving on girls houses. A classic? My '90s copy was part of the 55th printing(!) so somebody's still buying it.

Well, check this out :

http://www.gylesaero.com/aerobooks_search.shtml

I did a Google on Chevalier and one of his books and got that list.

The math in "Theory of Wing Sections" is definitely challenging. While it is of historical interest, I wouldn't spend too much time trying to understand it if your interests are practical. Before the advent of modern computers, aerodynamicists were forced to "shoehorn" problems into constructs that were tractable either analytically or using the limited computing power available. Many early methods (such as those in ToWS) became obsolete as computing power allowed problems to be attacked with fewer simplifying assumptions.

Right Shoe. I bought Abbott for the 400 pages of ordinates and polar data in the appendices. However, I only discovered after receiving it that it only covers NACA sections (nothing on Selig, Eppler, etc.) and the polars are described in Reynolds values of 3 million+, way too high for model applications. I love the "Look Inside" feature on Amazon because I can usually catch stuff like this but in this case it was totally missed. It looks like it may have been a useless purchase. I can't recommend this book for model designers except as a novelty.

DaRock, thanks for the link. You da man!

If the model is light enough the airfoil does not matter
If it is too heavy -it still doesn't matter
(short reading version )