ABSTRACT
A programme of shock tube turbulent mixing experiments using a pulsed laser sheet with Mie scattering from a seeded gas has highlighted a complex data extraction problem due to image blurring. The source of the problem has been identified as the presence of high-order multiple scattering from the seeding particles . The aim of the experiments is to investigate shock induced dynamic mixing of air with a dense gas (SF 6, sulphur hexafluoride) and provide quantitative data to validate a Richtmyer-Meshkov turbulent gas mixing code. Validation is by comparison between the experimental images and their corresponding plane • slice' through a full 3D numerical simulation. The simulation is by the A WE TURMOIL 3D code which is a semi-Lagrangian calculation in which the mesh moves with mean fluid velocity. Use of a relatively high seeding concentration is necessarily dictated by the sensitivity of the photographic film and available laser pulse energy. Meaningful quantitative
Plan View of Laser
Camera
Code Representation of Test Cell
1 60 x 320 x 400 cells representing the test cell containing "concentration of scatterers" data
Vertical array of cells with 2500 particles
