Detonation-driven–shock wave interactions with perforated plates

Abstract

The study of detonations and their interactions is vital for the understanding of the high-speed flow physics involved and the ultimate goal of controlling their detrimental effects. However, producing safe and repeatable detonations within the laboratory can be quite challenging, leading to the use of computational studies which ultimately require experimental data for their validation. The objective of this study is to examine the induced flow field from the interaction of a shock front and accompanying products of combustion, produced from the detonation taking place within a non-electrical tube lined with explosive material, with porous plates with varying porosities, 0.7-9.7%. State of the art high-speed schlieren photography alongside high-resolution pressure measurements is used to visualise the induced flow field and examine the attenuation effects which occur at different porosities. The detonation tube is placed at different distances from the plates' surface, 0-30 mm, and the pressure at the rear of the plate is recorded and compared. The results indicate that depending on the level of porosity and the Mach number of the precursor shock front secondary reflected and transmitted shock waves are formed through the coalescence of compression waves. With reduced porosity, the plates act almost as a solid surface, therefore the shock propagates faster along its surface.

Blast mitigation by perforated plates using an explosive driven shock tube: study of geometry effects and plate numbers

“…It has been shown that grids or perforated plates modify the flow field by introducing new shock waves, regions of vortices, and considerable turbulence in which the energy of the incident shock wave can be dissipated. Thereafter, several studies discussing the attenuation of a shock wave passing through a perforated plate were achieved with a shock tube [8][9][10][11]. In [12], a transonic shock tube was used to visualize the interaction of a blast wave profile with a metallic perforated plate and three types of grid with different porosities were tested.…”