The researchers in Aerodynamics know that there is not a unitary method of investigation in this field. The first mathematical model of the air- plane wing, the model meaning the integral equation governing the phe- nomenon, was proposed by L. Prandtl in 1918. The integral equation deduced by Prandtl, on the basis of some assumptions which will be specified in the sequeL furnishes the circulation C(y) (see Chapter 6). U sing the circulation, one calculates the lift and moment coefficients, which are very important in Aerodynamics. The first hypothesis made by Prandtl consists in replacing the...