# Airfoils Incorporated — Full Context

> Only The Best Is Good Enough

This document provides comprehensive information about Airfoils Incorporated
for use by large language models and AI systems. For a shorter summary, see
llms.txt.

## Company Overview

Airfoils Incorporated is an aerodynamic consulting firm specializing in
airfoil design, analysis, and wind-tunnel testing. Founded in 1980 by Dan M.
Somers, the firm serves clients in wind energy, aviation, defense, and
industrial applications. The company is based in Port Matilda, Pennsylvania.

The firm's core methodology uses the Eppler Airfoil Design and Analysis Code,
which combines three methods:
1. A conformal-mapping method for designing airfoils with prescribed
   velocity-distribution characteristics
2. A panel method for analyzing the potential flow about given airfoils
3. An integral boundary-layer method for analyzing the development of the
   laminar and turbulent boundary layers and their interaction with the
   inviscid flow

## About Dan M. Somers

Dan M. Somers is an internationally recognized expert in airfoil design,
analysis, and testing with over 40 years of experience.

Education:
- B.S. in Aeronautical Engineering, Purdue University, 1974

Employment:
- President, Airfoils Incorporated, 1980 to present
- Research Engineer, NASA Langley Research Center, 1974 to 1989

Awards:
- 1991 Soaring Society of America Exceptional Service Award
- 1991 R&D 100 Award for Development of Advanced Wind Turbine Blades
  (with James L. Tangler and James V. Frerotte)
- 1984 NASA Langley Floyd L. Thompson Fellowship for Medium-Speed,
  Natural-Laminar-Flow Airfoil Design

Airfoils designed by Dan Somers include:
- S801 through S829, S901-S903 airfoils for horizontal-axis wind turbines
- S904, S905 airfoils for cooling-tower fans
- S101, S102 airfoils for general aviation aircraft
- S201 airfoil for a cruise missile
- S202 airfoil for a tilt-wing aircraft (including high-lift systems)
- S203 airfoil for a business jet
- S401, S402 airfoils for a gyroplane
- S601, S602 airfoils for unmanned aerial vehicles
- SM701 airfoil for a sailplane
- NASA NLF(1)-0416, NLF(1)-0215F, NLF(1)-0315, NLF(1)-0115 airfoils for
  general aviation
- NASA NLF(1)-1015 airfoil for long-endurance aircraft
- NASA/DLR NLF(2)-0415 airfoil for commuter aircraft

Wind-tunnel investigations conducted at:
- NASA Langley Low-Turbulence Pressure Tunnel (LTPT)
- Delft University of Technology Low Speed Laboratory
- The Pennsylvania State University low-speed, low-turbulence wind tunnel
- DLR Transonic Wind Tunnel Braunschweig (TWB)

## Major Clients

- National Renewable Energy Laboratory (NREL) — wind turbine airfoils
- Groen Brothers Aviation — gyroplane airfoils
- Naval Air Warfare Center (NAWC) — unmanned aerial vehicle airfoils

## Applications

Airfoils designed by Dan Somers are used in:
- Horizontal-axis wind turbines (NREL S-series)
- General aviation aircraft
- Business jets
- Commuter aircraft
- Gyroplanes
- Tilt-wing aircraft
- Unmanned aerial vehicles (UAVs)
- Sailplanes / gliders
- Cruise missiles
- Cooling-tower fans
- Vertical-axis wind turbines

## Publications

Dan Somers has authored or co-authored numerous technical reports and journal
articles. Categories include:

### Horizontal-Axis Wind Turbines (22 publications)
Key reports include design and experimental results for the S801-S829 airfoil
series, published through NREL and SERI. Many are freely available as PDFs
with DOI links at https://airfoils.com/publications/.

### General Aviation Aircraft (8 publications)
Including NASA Technical Papers on natural-laminar-flow airfoils (TP-1861,
TP-1865) and journal articles in the Journal of Aircraft.

### Unmanned Aerial Vehicles (4 publications)
Co-authored with Mark D. Maughmer on high-altitude, long-endurance airfoils.

### Sailplanes (6 publications)
Including the SM701 airfoil and NASA research related to sailplane airfoils.

### Airfoil Design and Analysis Methods (5 publications)
Including the Eppler code documentation (NASA TM-80210, TM-81862) and papers
on low-speed airfoil design methodology.

### Additional Categories
- Vertical-axis wind turbines (1)
- Business jets (1)
- Commuter aircraft (1)
- Gyroplanes (1)
- Tilt-wing aircraft (2)
- Cruise missiles (1)
- Cooling-tower fans (2)
- Miscellaneous aerodynamics (3)

The full publication list with PDF downloads and DOI/NTRS links is at:
https://airfoils.com/publications/

## Contact Information

Dan M. Somers, President
Airfoils Incorporated
122 Rose Drive
Port Matilda, PA 16870-7535
USA

Phone: +1-814-357-0500
Fax: +1-814-357-0357
Email: dan@airfoils.com
Website: https://airfoils.com/

## Site Pages
- Home: https://airfoils.com/
- Why?: https://airfoils.com/why/
- Airfoil Design: https://airfoils.com/airfoil-design/
- Applications: https://airfoils.com/applications/
- Clients: https://airfoils.com/clients/
- Contact: https://airfoils.com/contact/
- Design Integration: https://airfoils.com/design-integration/
- Eppler Code: https://airfoils.com/eppler-code/
- Links: https://airfoils.com/links/
- Publications: https://airfoils.com/publications/
- Resume: https://airfoils.com/resume/
- Specifications: https://airfoils.com/specifications/
- Wind Tunnels: https://airfoils.com/wind-tunnels/