Introduction
This page was put together to provide a “One Stop Shop” for Mark Drela’s specially designed airfoils. The three main tables in this document list the different transitions and usage of the airfoils, as well as providing links for downloading the coordinates and related polar analysis.
Explanation
The nomenclature in the airfoil list requires a little explanation.
Most of Mark Drela’s AG airfoils have variants for use on different sections of a particular wing. The root airfoil is tweaked to perform better on the smaller chord found on the outer sections of the wing.
They are listed as:
“root ➔ tip”
or
“root ➔ mid1 ➔ mid2 ➔ tip”
to suggest how to blend the family of airfoils.
The letter near the end of an airfoil name stands for the flap hinge line location in respect to the leading edge.
| Letter | Hinge |
|---|---|
| a | 60% |
| b | 65% |
| c | 70% |
| d | 75% |
| e | 80% |
Airfoil transitions and uses
Wing Airfoils
| Airfoils | Usage | Airplane Names | Notes |
|---|---|---|---|
| AG03 ➔ AG11 | Built-up and solid-balsa small HLGs; Built-up small electrics needing large speed range | Wood Apogee | |
| AG04 ➔ AG04 ➔ AG08 ➔ AG09 ➔ AG10 | Composite HLGs | Apogee | Note 2;Breaks: 20%,80%,92% |
| AG04 ➔ AG08 | Composite HLGs, strongly favor launch and run; | Apogee, Taboo | Composite S8E rocket gliders |
| AG12 ➔ AG13 ➔ AG14 | Composite HLGs, roughly equal emphasis on float and run; | XP3 (polyhedral version) | |
| AG16 ➔ AG17 ➔ AG18 ➔ AG19 | Composite HLGs, emphasis on float; Composite light 2M poly gliders | Photon, Watson-Sidewinder; Composite Allegro | |
| AG25 ➔ AG26 ➔ AG27 | Composite heavier 2M poly gliders | ||
| AG24 ➔ AG25 ➔ AG26 | Composite 3M poly gliders; | Hallett Bubble Dancer | |
| AG31 ➔ AG32 ➔ AG33 | Built-up small aileron gliders | Wind Dancer | hinge at 75-80% |
| AG36 ➔ AG37 ➔ AG38 | Built-up 1.5m poly HLGs | - | |
| AG35 ➔ AG36 ➔ AG37 ➔ AG38 | Built-up light 2M and 3M poly gliders | Allegro-Lite, Bubble Dancer | |
| AG34 ➔ AG35 ➔ AG36 | Built-up heavier 3M poly gliders | - | |
| AG40d ➔ AG41d ➔ AG42d ➔ AG43d | Composite 3M aileron gliders | Aegea 3m | |
| AG45c ➔ AG46c ➔ AG47c | Composite 1.5M aileron HLGs | SuperGee | Note 2 |
| AG455ct ➔ AG46ct ➔ AG47ct | Composite 1.5M aileron HLGs | SuperGee II, XP3, TabooXL | |
| AG44ct ➔ AG45ct ➔ AG46ct ➔ AG47ct | Composite light 2M aileron gliders | Aegea 2m |
Tail Airfoils
| Airfoil(s) | Usage | Airplane Names | Notes |
|---|---|---|---|
| HT08 | All-moving small-glider tails | Allegro-Lite | can be thickened to 6-7% for larger gliders |
| HT12 | DLG and light 2M tails | Allegro-Lite | hinge at 35-50% chord |
| HT13 à HT12 | Heavy 2M tails | ||
| HT14 à HT12 | 3M tails | new Mantis | |
| HT21 | Built-up tails | Bubble Dancer | |
| HT22 | Cambered tails | SuperGee | |
| HT23 | Cambered DLG vertical tails | SuperGee |
Airfoil Coordinates and Polars
| Airfoil | Coordinates | CompuFoil COR files | Polars |
|---|---|---|---|
| AG03 | ag03.dat - 4 KB | AG03.COR - 4 KB | ag03_polars.pdf - 32 KB |
| AG04 | ag04.dat - 4 KB | AG04.COR - 4 KB | ag04_polars.pdf - 34 KB |
| AG08 | ag08.dat - 4 KB | AG08.COR - 4 KB | ag08_polars.pdf - 29 KB |
| AG09 | ag09.dat - 4 KB | AG09.COR - 4 KB | Note 1 |
| AG10 | ag10.dat - 4 KB | AG10.COR - 4 KB | Note 1 |
| AG11 | ag11.dat - 4 KB | AG11.COR - 4 KB | Note 1 |
| AG12 | ag12.dat - 4 KB | AG12.COR - 3 KB | – |
| AG13 | ag13.dat - 4 KB | AG13.COR - 3 KB | – |
| AG14 | ag14.dat - 4 KB | AG14.COR - 3 KB | – |
| AG16 | ag16.dat - 4 KB | AG16.COR - 3 KB | ag16_polars.pdf - 31 KB |
| AG17 | ag17.dat - 3 KB | AG17.COR - 3 KB | ag17_polars.pdf - 25 KB |
| AG18 | ag18.dat - 3 KB | AG18.COR - 3 KB | ag18_polars.pdf - 30 KB |
| AG19 | ag19.dat - 4 KB | AG19.COR - 3 KB | ag19_polars.pdf - 25 KB |
| AG24 | ag24.dat - 4 KB | – | – |
| AG25 | ag25.dat - 4 KB | – | – |
| AG26 | ag26.dat - 4 KB | – | – |
| AG27 | ag27.dat - 4 KB | – | – |
| AG31 | ag31.dat - 78 Byte | – | – |
| AG32 | ag32.dat - 78 Byte | – | – |
| AG33 | ag33.dat - 78 Byte | – | – |
| AG34 | ag34.dat - 4 KB | – | – |
| AG35 | ag35.dat - 4 KB | AG35.COR - 4 KB | ag35_polars.pdf - 31 KB |
| AG36 | ag36.dat - 4 KB | AG36.COR - 4 KB | ag36_polars.pdf - 25 KB |
| AG37 | ag37.dat - 4 KB | AG37.COR - 4 KB | ag37_polars.pdf - 30 KB |
| AG38 | ag38.dat - 4 KB | AG38.COR - 4 KB | ag38_polars.pdf - 24 KB |
| AG40d(-2) | ag40d-02r.dat - 4 KB | – | – |
| AG41d(-2) | ag41d-02r.dat - 4 KB | – | – |
| AG42d(-2) | ag42d-02r.dat - 4 KB | – | – |
| AG43d(-2) | ag43d-02r.dat - 4 KB | – | – |
| AG44ct-02r | ag44ct-02r.dat - 4 KB | AG44CT-02R.COR - 3 KB | – |
| AG45ct-02r | ag45ct-02r.dat - 4 KB | AG45CT-02R.COR - 3 KB | – |
| AG45c-03 | ag45c-03.dat - 4 KB | AG45C-03.COR - 3 KB | – |
| AG455ct-02r | ag455ct-02r.dat - 4 KB | AG455CT-02R.COR - 3 KB | – |
| AG46ct-02r | ag46ct-02r.dat - 4 KB | AG46CT-02R.COR - 3 KB | – |
| AG46c-03 | ag46c-03.dat - 4 KB | AG46C-03.COR - 3 KB | – |
| AG47ct-02r | ag47ct-02r.dat - 4 KB | AG47CT-02R.COR - 3 KB | – |
| AG47c-03 | ag47c-03.dat - 4 KB | AG47C-03.COR - 3 KB | – |
Notes:
- Polars not provided for tip airfoils as flow not really two-dimensional (2D) at the tip, so the analysis wouldn’t be particularly meaningful…
Tail Airfoil Coordinates
| Airfoil | Coordinates | CompuFoil COR files |
|---|---|---|
| ht05 | ht05.dat - 4 KB | HT05.COR - 4 KB |
| ht08 | ht08.dat - 4 KB | HT08.COR - 3 KB |
| ht12 | ht12.dat - 3 KB | HT12.COR - 3 KB |
| ht13 | ht13.dat - 3 KB | – |
| ht14 | ht14.dat - 3 KB | – |
| ht21 | ht21.dat - 3 KB | – |
| ht22 | ht22.dat - 3 KB | HT22.COR - 3 KB |
| ht23 | ht23.dat - 3 KB | HT23.COR - 3 KB |
Polar Comparisons
- Comparison: ag37, ag35, s3021 (re100k) - 21 KB
- Comparison: ag37, ag35, s3021 (re70k) - 20 KB
- Comparison: ag37, ag35, s3021 (re50k) - 19 KB
- Comparison: ag18, ag16, sa7035, rg15 (re100k) - 27 KB
- Comparison: ag18, ag16, sa7035 (re70k) - 20 KB
- Comparison: ag18, ag16, sa7035 (re50k) - 20 KB
- Comparison: ag03, ag04, ag08, s6063 (re 40k) - 28 KB
- Comparison: ag03, ag04, ag08, s6063 (re 30k) - 26 KB
- Comparison: ag03, ag04, ag08, s6063 (re 40k) ag2 - 28 KB
- Comparison: ag03, ag04, ag08, s6063 (re 30k) ag1 - 26 KB
Aileron Airfoils
- AG455ct
- AG46ct
- AG47ct
The main changes from the AG4xc DLG series are structural. The flap has been thickened (hence the “t” in the name) to better resist flutter. These sections should not need the flap LE to be faced off if an adequate bias skin is used. Using a thicker flap required the kinks at the 70% hinge location to be reduced, so that -2 flap now gives a smooth bottom surface, and 0 flap gives a smooth top surface. Previously this range was -3..0. The coordinates are provided with the -2 flap position put in, and the entire airfoils have also been rotated by 0.6 degrees to put the TE back on the y=0 axis (hence the “r” in the filename).
The center section has also been thinned and decambered slightly for more speed – the AG455ct is roughly midway between the AG45c and AG46c sections in camber and thickness. This should have a fairly small effect on the speed performance, probably within the variations due to building tolerances.
The recommended flap setting are:
- *-2 Launch, fast penetration (this is the provided shape)
- *0 Cruise
- *+2 Thermal
Poly Airfoils
- AG12
- AG13
- AG14
As usual for a poly airfoil, these were designed to balance the speed and float requirements, with a bit more emphasis on speed to reflect the general trend towards “fast and light”. They should be somewhat faster than the Allegro AG16-19 airfoils. They should be comparable in speed to the Apogee AG04-08 airfoils, but with a slightly better cruise L/D.
Tail Airfoils
The HT12,13,14 airfoils are specifically designed for RC glider tails. If constructed accurately, they will have complete absence of deadband even on the smallest HLG tails. They also have fully laminar flow for the lowest profile drag possible. At zoom and penetration speeds a “slab” tail will have nearly twice as much drag in comparison.
The thinnest airfoil should be used consistent with structural requirements. The recommendations are:
- 5.0% HT12 for HLGs and light 2M gliders
- 6.5% HT13 for heavier 2M and light Open gliders
- 7.5% HT14 for large heavy gliders
The airfoils can also be blended across the tail span, e.g. HT14 at root for structural merit, HT12 at tip for low core weight and minimum drag.
Thinning of the HT12 is not advised… max control power will start to degrade. Thickening of the HT14 is not advised… deadband will start to creep in.
For built-up tails, the TE can be made blunt by rotating each surface about the LE point to get the TE to the right thickness. Drag will increase slightly, but the nice control characteristics will be unaffected.
These airfoils favor a very wide control surface. The hinge is ideally at 40% chord, although a 50% hinge is almost as good. The max thickness locations are quite far forward, so using such wide flaps does not significantly reduce the bending strength of the fixed part of the tail.