A Method for the Instantaneous Measurement of Velocity and Temperature in High Speed Air Flow

摘要

A beam of ultrasonic sound waves is projected across an air stream the velocity and temperature of which are required. From the known ultrasonic frequency and the measured wave‐length, the temperature may be determined; and from the slope of the beam boundary, an approximate Mach number may be obtained. The method is applicable to steady‐flow problems as in wind tunnels or to transient‐flow problems such as the study of shock waves.