Experiments on the Wall-Pressure History in Shock Reflection Processes

Author: Baganoff, Donald

Year: 1964

Degree: Dissertation (Ph.D.)

Advisor: Liepmann, Hans Wolfgang

Committee Member: Unknown, Unknown

Option: Aeronautics

DOI: 10.7907/XK5D-HZ55

Abstract

NOTE: Text or symbols not renderable in plain ASCII are indicated by [...]. Abstract is included in .pdf document.

The normal reflection of a plane shock from a plane wall is investigated experimentally using a pressure gauge which has a risetime of 0.1 [....] and no overshoot. Pressure histories of 5 [.....] duration can be obtained with this gauge. The experiments were conducted on the end wall of the GALCIT 17-in.-diameter shock tube.

Experimental results for three aspects of the reflection process are discussed: (1) profile for the reflected shock front, (2) effect of a cold wall, and (3) effect of a real gas.

It is concluded that the effect of a cold wall must play a comparatively minor role in the reflection process since the thickness of the recorded profile is comparable to the thickness of the incident shock, and the pressure jump across the profile is about 85 per cent of the ideal value. Also, the pressure history immediately behind the reflected shock can be approximated by boundary layer theory. The effect of a real gas was studied in carbon dioxide and it is shown that the relaxation process behind the incident shock produces a large effect on the recorded pressure history which provides a method of measuring the vibrational relaxation time in carbon dioxide for high temperatures.

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