Photon Doppler Velocimetry Measurements of Shock Wave - Particle Curtain Experiments in the LANL Horizontal Shock Tube: Preliminary Results.

The horizontal shock tube (HST) at the Los Alamos National Lab (LANL) has been modified to enable experiments exploring particle curtain – shockwave interactions. These experiments aim to investigate the ability of photon doppler velocimetry (PDV) to measure the behavior of particles subjected to shock acceleration such as particle ejecta from detonation experiments. Previous work in the HST has focused on monodisperse individual particle drag behavior. Here, the facility has been modified to enable the creation of a polydisperse particle curtain with controllable curtain geometry and adjustable volume fraction.

The experiments use an array of diagnostics. The initial condition is characterized by using a Particle Doppler Phase Anemometry system to measure the volume fraction of the curtain, multi-frame shadowgraphy is used to characterize the shock-curtain interaction and multi-frame Mie scattering is implemented to enable Particle Image Velocimetry (PIV) to extract velocity distributions. A set of PDV probes are located downstream of the particle-curtain location, with their base frequency offset to allow velocity measurement of the particle curtain as a function of height within the HST.

We will present preliminary results from this set of experiments, showcasing comparisons of velocity data extracted from PIV and velocity distributions extracted from PDV measurements as a function of shock strength, particle curtain volume fraction and particle material properties.