Determination of the load distribution on a given wing
This is the direct problem broadly facing designers who wish to predict the performance of a projected wing before the long and costly process of model tests begin. This does not imply that such tests need not be carried out. On the contrary, they may be important steps in the design process towards a production aircraft.
The problem can be rephrased to suggest that the designers would wish to have some indication of how the wing characteristics vary as, for example, the geometric parameters of the project wing are changed. In this way, they can balance the aerodynamic effects of their changing ideas against the basic specification – provided there is a fairly simple process relating the changes in design parameters to the aerodynamic characteristics. Of course, this is stating one of the design problems in its baldest and simplest terms, but as in any design work, plausible theoretical processes yielding reliable predictions are very comforting.
The loading on the wing has already been described in the most general terms available and the overall characteristics are immediately to hand in terms of the coefficients of the loading distribution (Section 5.5). It remains to relate the coefficients (or the series as a whole) to the basic aerofoil parameters of planform and aerofoil section characteristics.