{
 "version": "2026-10-20",
 "license": "Dimension sheets: CC BY 4.0. Standard and published-size files: CC BY 4.0. Xem Studio's own designs (files_license = Xem Studio Design License): free to use and sell things from, not to redistribute as files — https://xemstudio.com/license/. Other publishers' files: their own license, linked beside them.",
 "slug": "nrel-s809-airfoil",
 "name": "NREL S809 airfoil",
 "kind": "standard",
 "category": "Airfoils",
 "group": "Other airfoils",
 "year": null,
 "question": "What is the exact shape of the NREL S809 airfoil?",
 "tags": [
  "airfoil",
  "wing section",
  "rc plane",
  "aerodynamics",
  "cambered airfoil"
 ],
 "aliases": [
  "s809",
  "nrel s809",
  "s809 wind turbine airfoil",
  "s809 coordinates",
  "NREL S809 airfoil",
  "NREL S809 coordinates",
  "NREL S809 dat",
  "NREL S809 STEP",
  "NREL S809 STL",
  "NREL S809 profile"
 ],
 "overall_mm": {
  "length": 100,
  "width": 20,
  "height": 20.96
 },
 "official_cad": false,
 "xem_status": "free-files",
 "les": false,
 "free_files": 1,
 "url": "https://xemstudio.com/objects/nrel-s809-airfoil/",
 "sheet_txt": "https://xemstudio.com/objects/nrel-s809-airfoil/sheet.txt",
 "sheet": {
  "basis": "Coordinates from NREL/SR-440-6918 Table 2; thickness, camber and section by Xem Studio",
  "overall_mm": {
   "length": 100,
   "width": 20,
   "height": 20.96
  },
  "notes": [
   "NREL S809: D. M. Somers, for NREL (wind-turbine airfoil). Maximum thickness 20.96 % of chord at 38.2 % chord; maximum camber 0.96 % of chord at 82.3 % chord.",
   "Coordinates from Table 2 of D.M. Somers, 'Design and Experimental Results for the S809 Airfoil' (NREL/SR-440-6918, 1997). The table starts just after the leading edge; the chord-line origin (0, 0) is used as the leading-edge point. Thickness and camber are computed by Xem Studio from those points (vertical distance at equal x, linear between points).",
   "The published trailing edge is sharp, so the section uses it as printed.",
   "The file is a 100 mm chord section, 20 mm deep: scale it uniformly to your chord, or import the STEP and sweep or loft it into a wing. Thickness scales with chord; the shape is the same at any size."
  ],
  "table": {
   "columns": [
    "parameter",
    "value",
    "source"
   ],
   "rows": [
    [
     "Max thickness",
     "20.96 % chord at 38.2 % chord",
     "computed from NREL/SR-440-6918 Table 2"
    ],
    [
     "Max camber",
     "0.96 % chord at 82.3 % chord",
     "computed from NREL/SR-440-6918 Table 2"
    ],
    [
     "Published points",
     "62 (32 upper, 31 lower, shared leading edge, the (0, 0) leading edge added)",
     "NREL/SR-440-6918 Table 2"
    ],
    [
     "Trailing edge as published",
     "sharp (closed)",
     "NREL/SR-440-6918 Table 2"
    ],
    [
     "y at x = 1.25 % chord",
     "upper +1.787 / lower -1.475 % chord",
     "linear between the published points (NREL/SR-440-6918 Table 2)"
    ],
    [
     "y at x = 2.5 % chord",
     "upper +2.705 / lower -2.254 % chord",
     "linear between the published points (NREL/SR-440-6918 Table 2)"
    ],
    [
     "y at x = 5 % chord",
     "upper +4.069 / lower -3.492 % chord",
     "linear between the published points (NREL/SR-440-6918 Table 2)"
    ],
    [
     "y at x = 7.5 % chord",
     "upper +5.104 / lower -4.569 % chord",
     "linear between the published points (NREL/SR-440-6918 Table 2)"
    ],
    [
     "y at x = 10 % chord",
     "upper +5.951 / lower -5.544 % chord",
     "linear between the published points (NREL/SR-440-6918 Table 2)"
    ],
    [
     "y at x = 15 % chord",
     "upper +7.300 / lower -7.230 % chord",
     "linear between the published points (NREL/SR-440-6918 Table 2)"
    ],
    [
     "y at x = 20 % chord",
     "upper +8.332 / lower -8.594 % chord",
     "linear between the published points (NREL/SR-440-6918 Table 2)"
    ],
    [
     "y at x = 25 % chord",
     "upper +9.114 / lower -9.665 % chord",
     "linear between the published points (NREL/SR-440-6918 Table 2)"
    ],
    [
     "y at x = 30 % chord",
     "upper +9.651 / lower -10.434 % chord",
     "linear between the published points (NREL/SR-440-6918 Table 2)"
    ],
    [
     "y at x = 40 % chord",
     "upper +10.106 / lower -10.804 % chord",
     "linear between the published points (NREL/SR-440-6918 Table 2)"
    ],
    [
     "y at x = 50 % chord",
     "upper +9.500 / lower -9.350 % chord",
     "linear between the published points (NREL/SR-440-6918 Table 2)"
    ],
    [
     "y at x = 60 % chord",
     "upper +7.724 / lower -6.819 % chord",
     "linear between the published points (NREL/SR-440-6918 Table 2)"
    ],
    [
     "y at x = 70 % chord",
     "upper +5.771 / lower -4.232 % chord",
     "linear between the published points (NREL/SR-440-6918 Table 2)"
    ],
    [
     "y at x = 80 % chord",
     "upper +3.900 / lower -2.014 % chord",
     "linear between the published points (NREL/SR-440-6918 Table 2)"
    ],
    [
     "y at x = 90 % chord",
     "upper +2.044 / lower -0.439 % chord",
     "linear between the published points (NREL/SR-440-6918 Table 2)"
    ],
    [
     "y at x = 95 % chord",
     "upper +0.996 / lower -0.019 % chord",
     "linear between the published points (NREL/SR-440-6918 Table 2)"
    ],
    [
     "Coordinates source",
     "Design and Experimental Results for the S809 Airfoil, NREL/SR-440-6918 (1997), Table 2 (coordinates)",
     "NREL (D.M. Somers)"
    ]
   ]
  }
 },
 "sheet_text": "NREL S809 airfoil — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/nrel-s809-airfoil/  (sheet CC BY 4.0; files Xem Studio Design License, https://xemstudio.com/license/)\nBasis: Coordinates from NREL/SR-440-6918 Table 2; thickness, camber and section by Xem Studio\nCatalog version: 2026-10-20\n\nOverall (mm): length 100.0, width 20.0, height 20.96\n- NREL S809: D. M. Somers, for NREL (wind-turbine airfoil). Maximum thickness 20.96 % of chord at 38.2 % chord; maximum camber 0.96 % of chord at 82.3 % chord.\n- Coordinates from Table 2 of D.M. Somers, 'Design and Experimental Results for the S809 Airfoil' (NREL/SR-440-6918, 1997). The table starts just after the leading edge; the chord-line origin (0, 0) is used as the leading-edge point. Thickness and camber are computed by Xem Studio from those points (vertical distance at equal x, linear between points).\n- The published trailing edge is sharp, so the section uses it as printed.\n- The file is a 100 mm chord section, 20 mm deep: scale it uniformly to your chord, or import the STEP and sweep or loft it into a wing. Thickness scales with chord; the shape is the same at any size.\n\nparameter  value  source\nMax thickness  20.96 % chord at 38.2 % chord  computed from NREL/SR-440-6918 Table 2\nMax camber  0.96 % chord at 82.3 % chord  computed from NREL/SR-440-6918 Table 2\nPublished points  62 (32 upper, 31 lower, shared leading edge, the (0, 0) leading edge added)  NREL/SR-440-6918 Table 2\nTrailing edge as published  sharp (closed)  NREL/SR-440-6918 Table 2\ny at x = 1.25 % chord  upper +1.787 / lower -1.475 % chord  linear between the published points (NREL/SR-440-6918 Table 2)\ny at x = 2.5 % chord  upper +2.705 / lower -2.254 % chord  linear between the published points (NREL/SR-440-6918 Table 2)\ny at x = 5 % chord  upper +4.069 / lower -3.492 % chord  linear between the published points (NREL/SR-440-6918 Table 2)\ny at x = 7.5 % chord  upper +5.104 / lower -4.569 % chord  linear between the published points (NREL/SR-440-6918 Table 2)\ny at x = 10 % chord  upper +5.951 / lower -5.544 % chord  linear between the published points (NREL/SR-440-6918 Table 2)\ny at x = 15 % chord  upper +7.300 / lower -7.230 % chord  linear between the published points (NREL/SR-440-6918 Table 2)\ny at x = 20 % chord  upper +8.332 / lower -8.594 % chord  linear between the published points (NREL/SR-440-6918 Table 2)\ny at x = 25 % chord  upper +9.114 / lower -9.665 % chord  linear between the published points (NREL/SR-440-6918 Table 2)\ny at x = 30 % chord  upper +9.651 / lower -10.434 % chord  linear between the published points (NREL/SR-440-6918 Table 2)\ny at x = 40 % chord  upper +10.106 / lower -10.804 % chord  linear between the published points (NREL/SR-440-6918 Table 2)\ny at x = 50 % chord  upper +9.500 / lower -9.350 % chord  linear between the published points (NREL/SR-440-6918 Table 2)\ny at x = 60 % chord  upper +7.724 / lower -6.819 % chord  linear between the published points (NREL/SR-440-6918 Table 2)\ny at x = 70 % chord  upper +5.771 / lower -4.232 % chord  linear between the published points (NREL/SR-440-6918 Table 2)\ny at x = 80 % chord  upper +3.900 / lower -2.014 % chord  linear between the published points (NREL/SR-440-6918 Table 2)\ny at x = 90 % chord  upper +2.044 / lower -0.439 % chord  linear between the published points (NREL/SR-440-6918 Table 2)\ny at x = 95 % chord  upper +0.996 / lower -0.019 % chord  linear between the published points (NREL/SR-440-6918 Table 2)\nCoordinates source  Design and Experimental Results for the S809 Airfoil, NREL/SR-440-6918 (1997), Table 2 (coordinates)  NREL (D.M. Somers)\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- NREL (D.M. Somers): Design and Experimental Results for the S809 Airfoil, NREL/SR-440-6918 (1997), Table 2 (coordinates) — web — US Government-sponsored report; coordinates are facts — https://www.osti.gov/biblio/437668\n\nFree files (Xem Studio Design License, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/nrel-s809-airfoil/index.json\nAPI: https://xemstudio.com/api/geometry?object=nrel-s809-airfoil\n",
 "sources": [
  {
   "publisher": "NREL (D.M. Somers)",
   "title": "Design and Experimental Results for the S809 Airfoil, NREL/SR-440-6918 (1997), Table 2 (coordinates)",
   "url": "https://www.osti.gov/biblio/437668",
   "formats": [
    "web"
   ],
   "license": "US Government-sponsored report; coordinates are facts",
   "license_verified": true,
   "hosted": false
  }
 ],
 "xem": {
  "status": "free-files",
  "sheet_free": true,
  "mesh_price_usd": null,
  "step_price_usd": null,
  "tolerance_mm": null
 },
 "related": [
  "clark-y-airfoil",
  "eppler-e387-airfoil",
  "mh32-airfoil",
  "ag35-airfoil",
  "s7075-airfoil",
  "sd7037-airfoil",
  "naca-2412-airfoil",
  "naca-0012-airfoil"
 ],
 "fits": [],
 "dimensions": "exact (nominal, no printing tolerance)",
 "dimension_rule": "All geometry on Xem Studio is exact (nominal, true size) with no printing tolerance. Where a part meets another part, the object lists its mating features (feature, exact size, what it mates with, fit class: press, slide, run, socket, clamp or designed). Apply your process's allowance to those features only; 'designed' gaps are part of the design and stay as drawn.",
 "mating": [],
 "faq": [
  {
   "q": "How thick is the NREL S809?",
   "a": "Maximum thickness 20.96 % of chord at 38.2 % chord: 20.96 mm on a 100 mm chord (computed from NREL/SR-440-6918 Table 2)."
  },
  {
   "q": "How much camber does the NREL S809 have?",
   "a": "Maximum camber 0.96 % of chord at 82.3 % chord (computed from NREL/SR-440-6918 Table 2)."
  },
  {
   "q": "How do I use it for my wing?",
   "a": "Scale the 100 mm section to your chord (e.g. 180 mm chord = 180 % scale), then extrude or loft between root and tip sections. For a tapered wing, scale a root and a tip copy and loft between them."
  }
 ],
 "files_license": {
  "name": "Xem Studio Design License",
  "holder": "Xem Studio",
  "url": "https://xemstudio.com/license/",
  "note": "Xem Studio's own design: free to use, print, modify and sell things made from it; not to be republished or redistributed as files."
 },
 "offers": [
  {
   "file": "nrel-s809-airfoil-section-100mm-chord",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "Xem Studio Design License",
   "step": "https://xemstudio.com/files/hardware/nrel-s809-airfoil/nrel-s809-airfoil-section-100mm-chord.step",
   "stl": "https://xemstudio.com/files/hardware/nrel-s809-airfoil/nrel-s809-airfoil-section-100mm-chord.stl",
   "note": "NREL S809 section, 100 mm chord × 20 mm span, 61 points from the published coordinates, single trailing-edge point (scale to your chord)"
  }
 ],
 "markdown": "https://xemstudio.com/objects/nrel-s809-airfoil/index.md"
}