Shock tube experimentation utilizing advance diagnostics for the study of an impulsively accelerated multiphase cylinder

Abstract

Shock driven multiphase instabilities (SDMI) are unique physical phenomena that have far-reaching practical applications in engineering and science. The instability is present in high-energy explosions, scramjet combustors, and supernovae events. The SDMI arises when a multiphase interface is impulsively accelerated by the passage of a shockwave. Complex particle-gas interactions are the driving mechanism of the SDMI. Particle effects such as lag, aerodynamic breakup, and mass, momentum and energy exchanges with the gas all contribute to the development of the instability. An experiment has been developed for studying the SDMI at the University of Missouri's shock tube facility. A multiphase interface is created and flowed into the shock tube test section where it is accelerated by the passage of a planar shock wave. Dynamic imaging of the interface was used to analyze the flow morphology. The effects of Atwood number (particle seeding), particle size, and a secondary acceleration of the interface were examined providing a qualitative and quantitative analysis of the flow. Non-intrusive flow visualization techniques such as Particle Image Velocimetry and Planar Laser Induced Fluorescence were used to obtain quantitative measures of multiphase effects. New imaging techniques were designed for the simultaneous imaging of droplet and vapor fields. Measurements of particle lag distance, carrier and dispersed phase velocity, and vorticity were made. The experimental set up and findings will be discussed in detail.