Weak shock wave reflections from concave curved surfaces
Date
2013-02-05
Authors
Gruber, Sebastien
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
The reflection of very weak shock waves from concave curved surfaces has not been
well documented in the past and recent studies have shown the possible existence of a
variation in the reflection configuration evolution as a very weak shock wave
encounters an increasing gradient on the reflecting surface. The current study set out
to investigate this anomaly using high resolution photography and numerical
simulations. Shock tube tests were done on various concave circular and parabolic
geometries, all with zero initial ramp angle. Unlike for the stronger shock wave case,
the results showed that for very weak Mach numbers, Ms < 1.1, there is a region in
which the reflection configuration resembles that of a regular reflection. This region
exists after the triple point of the Mach reflection meets the reflecting surface and
prior to the formation of the additional shock structures that represent a transitioned
regular reflection. The Mach and transitioned regular reflections at 1.03 < Ms < 1.05
also exhibited no signs of a shear layer, possibly due to the lack of a clear
discontinuity at the triple point.