Piecewise smooth approximation of the dependence of the body base drag coefficient on the Mach number

A piecewise smooth approximation technique based on the least squares method is proposed, which makes it possible to obtain complex high-order functional dependencies on a single variable with high accuracy, while ensuring consistency with the physical nature of the approximated data and minimizing jumps in function values at the boundaries of the partition intervals. A criterion for assessing the approximation quality is proposed, which includes such indicators as relative deviation, consistency of the approximating values with the physical nature of the approximated data, and the quality of approximation near the boundaries of the subdomains. The optimal partition is determined using an evolutionary optimization algorithm. The proposed technique is applied to approximate the dependence of the missile fuselage base drag coefficient on the Mach number.

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