The calculation of the wave drag of a family of low-drag axisymmetric nose shapes of fineness ratio 4.5 at zero incidence at supersonic speeds

The pressure drag coefficients of a particular family of convex logarithmic projectile nose shapes in which the nose angle is an important parameter have been calculated over a range of supersonic Mach numbers using a rapid approximate method due to Zienkiewicz.5 The optimum nose angle for minimum wave drag of these profiles for each Mach number has been obtained. It is shown that above N = 1.5„ approximately, the optimum shape is similar to the hypersonic optimum profile and has the sane or- less wave drag than this profile. However for values of M/F, where P is the fineness ratio, below 0.5, both the hypersonic and the logarithmic optimum profiles have a higher drag than the so-called cubic profile (Ref, 9).