Some sources of aerodynamic geometry and experimental data for use in code evaluation are listed here. They are invaluable for making sure that you are using a computational aerodynamics code correctly. Always check a code that is new to you against known results, which we already discussed in Chapter 2. Note that rigorous validation of codes requires very careful analysis and an understanding of possible experimental, as well as computational, error (which was also discussed in Chapter 10). Most of the NASA and NACA reports cited here are available from the NASA Technical Reports Server, http://ntrs.nasa.gov/; a mirror website for NACA reports is available from Cranfield University at http://naca.central.cranfield.ac.uk/. Some of the reports listed here will also be provided at the book website: http://www.cambridge.org/aerodynamics. Most of the results are presented graphically, so a utility such as DataThief or Engauge is needed to digitize the data for comparison with calculations.

Books

Abbott, I.H. and von Doenhoff, A.E., Theory of Airfoil Sections, New York: Dover, 1959: This is a book every aerodynamicist should have. Look in the references for the original NACA airfoil reports. The aerodynamic descriptions contained in the reports are unsurpassed. However, beware of the actual data presented prior to 1939, which is when they discovered that they had to apply a different support interference correction to the measured results (see NACA Report 669 by Jacobs for details). Note that pressure distributions for airfoils are fairly rare. See also NACA Report 824, which is an earlier compendium similar to this book.

Aerodynamicists control the flowfield through geometry definition and are always interested in possible geometric shapes that would be useful in design. This appendix provides the detailed definition of many of the classic shapes frequently specified in aerodynamics. It is not intended to be encyclopedic, but will provide a good starting point for where to obtain geometric definitions for aerodynamic shapes.

The NACA Airfoils

The NACA (National Advisory Committee for Aeronautics) airfoils were designed during the period from 1929 through 1947 under the direction of Eastman Jacobs at the NACA’s Langley Field Laboratory (now NASA Langley Research Center). Most of the airfoils were based on simple geometrical descriptions of the section shape, although the 6 and 6A series were developed using theoretical analysis and don’t have simple shape definitions. Although a new generation of airfoils has emerged as a result of improved understanding of airfoil performance and the ability to design new airfoils using computational methods, the NACA airfoils are still useful in many aerodynamic design applications. A number of references have been included to allow the reader to study both the older NACA literature and the new airfoil design ideas. Taken together, this literature provides a means of obtaining a rather complete understanding of the ways in which airfoils can be shaped to obtain desired performance characteristics.