Characteristics - Natural Coordinates

This lecture focuses on studying two-dimensional supersonic flows using natural coordinates based on streamlines. The instructor explains the concept of streamlines, the definition of a streamline, and the limitations of using natural coordinates. The lecture also covers the introduction of natural coordinates by professors Linnman and Roscoe at Caltech in the 1950s, emphasizing their pedagogical value and practical applications. The use of natural coordinates to describe flow phenomena and the derivation of curvature radii for streamlines and normal families are discussed in detail, highlighting the rigorous geometric interpretations and unit consistency in the calculations.