Mach angle[′mäk ‚aŋ·gəl]
The vertex half angle of the Mach cone generated by a body in supersonic flight.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The acute angle between a weak shock wave and a free-stream airflow. Hence, at Mach 1, the Mach angle is 90°, and, thereafter, its value is equal to sin−1 × 1/M. It is represented by the symbol μ. See also Mach cone.
An Illustrated Dictionary of Aviation Copyright © 2005 by The McGraw-Hill Companies, Inc. All rights reserved