Optical measurements of the mutual reflection of two-plane shock waves

Book · Sun Dec 31 04:00:00 EST 1995

OSTI ID:220739

Barbosa, F J; Skews, B W ^[1]

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1. Univ. of the Witwatersrand, Johannesburg (South Africa). School of Mechanical Engineering

A bifurcated shock tube is used to create two synchronized waves of equal strength. Essentially a single shock wave is split symmetrically in two, the two waves then are later brought back together at a trailing edge of a wedge to interact, the plane of symmetry acting as an ideal rigid wall. The normal method of studying mach reflections is to allow a plane shock wave to impinge on a wedge, however the boundary layer growth on the wedge surface effectively ensures that the flow direction behind the Mach stem does not have to satisfy the boundary condition of being parallel to the surface of the wedge. Thus the transition from regular to Mach reflection occurs at higher angles of incidence than theory allows. The present experiment was initiated to generate data on the ideal cause of reflection off a plane wall. The advantage of the new system is that like classical theory and computational solutions of the inviscid Euler equations, the boundary layer no slip condition is not imposed at the plane of reflection. Optical methods are used to investigate the post-shock flow, as well as to help explain the complex interactions which occur when the two shock waves are not synchronized. These interactions show many very interesting features and clearly indicate the need for higher resolution measurements such as are obtained using holographic interferometry, and also to extend the work to different wedge angles and Mach numbers.

• OSTI ID: 220739
• Report Number(s): CONF-950793--; ISBN 0-8194-1905-2
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
DIFFRACTION
EXPERIMENTAL DATA
FLOW VISUALIZATION
REFLECTION
SHOCK WAVES
SYNCHRONIZATION