Accession Number:

AD0604111

Title:

INTERFEROMETRIC STUDY OF SUPERSONIC PHENOMENA. PART III. BOUNDARY LAYER AND SHOCK WAVE INTERACTIONS OBSERVED ALONG PROBES AND WIRES IN SUPERSONIC AIR STREAMS

Descriptive Note:

Corporate Author:

PRINCETON UNIV NJ PALMER PHYSICAL LAB

Personal Author(s):

Report Date:

1947-02-19

Pagination or Media Count:

24.0

Abstract:

In earlier reports PB-118 682 and AD-604 112 of this series it was shown how quantitative values of density, pressure, temperature, velocity and Mach number in supersonic gas streams could be obtained optically by the use of an interferometer. The Mach number M may be obtained independently by making shadow photographs of the head wave of a narrow probe placed in the stream. Probe and interferometer Mach number values were in good agreement in a homogeneous stream from a Laval nozzle, but in complete disagreement in an inhomogeneous expanding air jet in the region where standing shock waves occur. This discrepancy was traced to the influence of the standing shocks on the air flowing at low velocity in the boundary layer along the probe. The shock pressure may cause a separation of the stream from the probe, and a configuration of normal and oblique shocks arises as a result at the region of separation. Further experiments made in a strictly one-dimensional stream show an analagous separation of flow when a normal standing shock wave intercepts the boundary layer. The theory of separation is discussed. This report includes the details of the methods of applying the Mach interferometer to an axially symmetric flow pattern. The density distribution in such an air jet from a circAuthor

Subject Categories:

  • Fluid Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE