# Radius of a Sears–Haack Body

## Description

The Sears–Haack body is the shape with the lowest theoretical wave drag in supersonic flow, for a given body length and given volume. The mathematical derivation assumes small-disturbance (linearized) supersonic flow, which is governed by the Prandtl-Glauert equation. The Sears–Haack body is pointed at each end and grows smoothly to a maximum and then decreases smoothly toward the second point.

A local radius is related to the maximum radius (at the center of the shape) and ratio of the distance from the nose to the whole body length (always between 0 and 1).

## Variables

r_{x} | Local radius (m) |

R_{max} | Maximym radius (at the center of the shape) (m) |

x | ratio of the distance from the nose to the whole body length ( x between 0 and 1) (dimensionless) |