The Shock Tube in Aerodynamic and Structural Research

Abstract

A shock tube usually consists of a cylindrical tube of constant cross-section which is divided into two chambers by a frangible diaphragm stretched across the tube. The two chambers initially have different gas pressures, thus putting a differential pressure across the diaphragm. In operation the stressed diaphragm is punctured by a knife or is spontaneously ruptured by increasing the differential pressure beyond the burst point. Following rupture of the diaphragm, pressure waves and expansion waves propagate into the low-and high-pressure chambers, respectively, and in turn are reflected from the open br closed ends of their respective chambers. The irregular pattern of compression waves proceeding into the lowpressure chamber tends to coalesce, forming a normal shock wave which propagates into the low-pressure gas at rest, setting the gas in motion behind the shock wave and also raising the pressure, temperature, and density. The pattern of rarefaction waves propagating into the high-pressure chamber tends to spread out.Shock tubes with widely differing physical characteristics of length, crosssection, position of diaphragm, pressures, and gases have been used for many purposes. They were initially used to study shock-wave formation and propagation and there still remains considerable work to be done in this field-in the study of shock-wave and expansion reflections, and refraction at gaseous interfaces and at solid surfaces. Related to these are the studies of blast propagation over obstacle shapes of interest. Gaseous detonation and deflagration studies have been made in shock tubes. Shock tubes designed to serve as short-duration wind tunnels, subsonic, transonic, and supersonic, are in use. There are many other special-purpose uses of shock tubes.The Massachusetts Institute of Technology shock tube has been designed for use in the study of the effect of unsteady pressure forces on aircraft and aircraft structures, as well as for use as a short-duration wind tunnel for the subsonic, transonic, and supersonic regions. For many of the principal features of design, the ideal theory of shock-tube operation can be employed.One-dimensional compressible-fluid-flow equations suffice to solve the problem.

Dynamics of rapidly depressurized multiphase shock tubes

“…Their original widespread popularity has largely been owed to their ability to consistently capture highly compressible physics at a reduced scale. Due to this, their use has also become a key part of the engineering design process in many fields, with perhaps the most notable field being aircraft design (Stever & Bisplinghoff 1954). In many problems, shock tubes have been adopted as a capable tool in the reproduction and better understanding of the underlying physics.…”