Appendix З

Ordinates for nearly 200 different aerofoils are given in this appendix, together with four low drag bodies (Young bodies) for fuselages, fairings, wheel spats etc. Not all profiles will be satisfactory for models, some have been included only to amplify comments in the text The modeller should choose his aerofoils with discretion, bearing in mind the general principles discussed in the relevant chapters.

The profile drawings given here have been plotted by a computer. In many cases, the results are accurate enough for the drawing to be enlarged or reduced photographically to produce a perfect template outline for modelling. In other cases, where the ordinates give a coarser outline, the mechanical plotter produces an angular drawing with segments of straight lines and other small irregularities. In these cases the modeller should smooth the outline with a ‘zip’ or ‘French’ curve before cutting the template. The ordinates for the Wortmann M 2 aerofoil in particular produce an irregular, corrugated leading edge. This should be smoothed in practice. The corrugations are a result of the approximate methods of calculations used by Wortmann for this very early, low speed aerofoil.

Hand plotting is laborious but can produce accurate results if carefully done. The method is described in most elementary books on aeromodelling. The more advanced aerofoils given in this appendix have been produced by computer and the old, standard plotting points are not used. Instead there may be different chord stations for upper and lower surfaces.

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