Measurements in the Turbulent Boundary Layer at Constant Pressure in Subsonic and Supersonic Flow. Part II. Laser-Doppler Velocity Measurements.

摘要

Experiments have been carried out using laser-Doppler velocimetry in conjunction with Pitot and surface-friction instrumentation for the measurement of the mean flow, the velocity fluctuations, and the Reynolds stresses in turbulent boundary layers at constant pressure in subsonic and supersonic flows. Part I of this work was a detailed analysis of the mean flow as observed using Pitot-tube, Preston-tube, and floating-element balance instrumentation. The present work (Part II) is a description of both the mean and the fluctuating components of the flow, and of the Reynolds stress as observed using a dual forward-scattering laser-Doppler velocimenter. A detailed description of the instrument, and of the data analysis techniques, have been included in order to fully document the data. A detailed comparison is made between the laser-Doppler results and those presented in Part I, and an assessment is made of the ability of the laser-Doppler velocimeter to measure the details of the flows involved.