Airfoil documents

There is an interesting document on Selig's page:
http://www.ae.uiuc.edu/m-selig/uiuc_lsat/vol4/NREL-SR-500-34515.pdf.

It covers for example wind tunnel results for Wortmann FX63-137 at low Reynolds numbers.

Links to NASA tech papers about airfoils
Covers NLF 215F

Airfoils in dwg format

Airfoils in dwg format

Low cost UAV design

LINK: Low-cost Expendable UAV Final Report

Reynold's number calculator

http://aero.stanford.edu/StdAtm.html

Aircraft calculator web page

I found this:

http://anton.panchishin.com/docs/aircraftcalc.html

I am not sure how useful it is, but just for fun, enjoy.

Airspeed at sea level

I got interesting airspeed calculator Excel-sheet from Petri Flander. I have been calculating those things with my aircraft design program and by hand before, but it is surprisingly handy to see the effect of various flat plate drag areas and their effect to the airspeed. Great input for my program which I am writing the UI for with Qt right now, I may do also graphical output for these parameters, would be fun to have. This was actually also useful to reverse-engineer the flat plate drag areas of various aircrafts. For example I came up with 4,7 ft2 for Cirrus SR20 where Lancair ES (=same as Columbia 400) is 4,0, so Cirrus is a slightly less efficient than the Columbia (which is evident also from the performance numbers comparing SR22 and Columbia 400). Interesting is that I came up with 9 for C152, which is a terribly bad figure. And Zenair CH701 produced a number around 18 which was reverse-engineered from real performance numbers I have heard from a Zenair pilot. Couldn't get much worse than that. BD-5 has very low figure of 0,9 and Vmax probe is at 0,3 (these were obtained from elsewhere). A composite BD-5 with rear body laminar flow suction (with more laminar body shape as well) and some high tech airfoil like the NLF414F could be super-efficient. However, the issues with low Reynolds number from Vmax probe apply, it will have seriously dangerous stall charasteristics without modifications to the airfoil or wing.

Here is a copy paste from the sheet with flat plate drag areas from 0.3 (Vmax probe) to 4 (Lancair ES):

        Aircraft speed, km/h                    Prop eff        0,85    Dens.ratio      1,000       $

Drag area            
ft2     25      40      60      80      85      90      100    <- Total hp  (Rotax 914)
4       148     173     198     218     223     227     235     127,053 kts
3,00    163     191     218     240     245     250     259     139,840 kts
2,40    176     205     235     259     264     269     279     150,639037908943        kts
2,30    178     208     238     262     268     273     283     152,791314948939        kts
2,20    181     211     242     266     272     277     287     155,07211859505 kts
2,12    183     214     245     270     275     280     290     156,998677308782        kts
2,10    184     215     246     270     276     281     291     157,495511877874        kts
2,00    187     218     250     275     281     286     296     160,077864487362        kts
1,90    190     222     254     280     285     291     301     162,838370152973        kts
1,80    193     226     259     285     291     296     307     165,799714672936        kts
1,70    197     230     264     290     296     302     313     168,988949701208        kts
1,60    201     235     269     296     302     308     319     172,438652178898        kts
1,50    205     240     275     303     309     315     326     176,188487565227        kts
1,40    210     246     281     310     316     322     334     180,28735558483 kts
1,30    215     252     288     317     324     330     342     184,796395706893        kts
1,20    221     259     296     326     333     339     351     189,793294797389        kts
1,10    228     266     305     336     342     349     361     195,378626469698        kts
1,00    235     275     315     346     353     360     373     201,685471089846        kts
0,90    243     285     326     359     366     373     386     208,894550582996        kts
0,88    245     287     328     361     369     376     389     210,46524527855 kts
0,50    296     346     396     436     445     454     470     254,107770484061        kts
0,31    347     406     465     512     522     532     551     298,003054739616        kts

Reference library

Here is list of some of the books I have:
Aerodynamics for Engineers
Fundamentals of Aerodynamics, by John Anderson
MODERN AIRCRAFT DESIGN, Volume 1 5th Edition, by Martin Hollmann.
MODERN AIRCRAFT DESIGN, Volume 2 4th Edition, by Martin Hollmann.
COMPOSITE AIRCRAFT DESIGN. REVISED 2003. By Dr. Hal Loken and Martin Hollmann.
MODERN AIRCRAFT DRAFTING by Eric and Martin Hollmann.
ADVANCED AIRCRAFT DESIGN by Martin Hollmann.
BRUCE CARMICHAEL'S PERSONAL AIRCRAFT DRAG REDUCTION

Aircraft Design : A Conceptual Approach

Daniel P. Raymer / Hardcover / 4th Ed. Published 2006

Theory of Flight

Richard Von Mises, Richard Von Mises

Aircraft Performance and Design

John D. Anderson / Hardcover / Published 1998

Sportplane Construction Techniques : A Builder's Handbook (Tony Bingelis Ser.))

Tony Bingelis; Paperback

Interesting aircraft design - LH10

This plane has some of the elements I have been thinking of an efficient aircraft to have:

http://www.lhaviation.com/site_frame/bases_marges/index.htm

Specs promise 200 kts with 100 hp. Lets see. The plane has already flown, but not yet tests that determine top speed.

According to my calculations, providing they are right, this is not that much out of place. This plane in fact, is pretty much like a two place Vmax Probe. If the airflow stays laminar in the fuselage and wings, the 200 kts might be doable. The relation of stall speed and top speed of the 3.77 projected for this plane is a reachable value. Very interesting to see how it performs and if it does not go 200 kts, why. According to what I have read and would estimate, the drag coefficient of the LH10 should be very small unless there is something wrong that causes the airflow to separate.

The view from the LH10 seems to be as spectacular than from a glider. Would be excellent aircraft for flying for fun.

The airfoil used on this aircraft is particularly interesting. Reasons:
- E.g. NLF414F produces very low drag and very high glide ratio, but not without restrictions - the area of usable Reynold's number is limited which limits the chord of the wing to a rather long one, and the wings of the LH10 would already be below that limit. They say that it is a wind turbine airfoil. I haven't tried simulating the wind turbine airfoils yet, it has not occurred to me that they could be actually be useful on aircraft. However, this seems to prove that this was wrong assumption, and they are in the UIUC database for a reason. Lots of airfoils to investigate...