  The ability to control the behavior of fluid instabilities at material
interfaces, such as the shock-driven Richtmyer--Meshkov instability, is a grand
technological challenge with a broad number of applications ranging from
inertial confinement fusion experiments to explosively driven shaped charges.
In this work, we use a linear-geometry shaped charge as a means of studying
methods for controlling material jetting that results from the
Richtmyer--Meshkov instability. A shaped charge produces a high-velocity jet by
focusing the energy from the detonation of high explosives. The interaction of
the resulting detonation wave with a hollowed cavity lined with a thin metal
layer produces the unstable jetting effect. By modifying characteristics of the
detonation wave prior to striking the lined cavity, the kinetic energy of the
jet can be enhanced or reduced. Modifying the geometry of the liner material
can also be used to alter jetting properties. We apply optimization methods to
investigate several design parameterizations for both enhancing or suppressing
the shaped-charge jet. This is accomplished using 2D and 3D hydrodynamic
simulations to investigate the design space that we consider. We also apply new
additive manufacturing methods for producing the shaped-charge assemblies,
which allow for experimental testing of complicated design geometries obtained
through computational optimization. We present a direct comparison of our
optimized designs with experimental results carried out at the High Explosives
Application Facility at Lawrence Livermore National Laboratory.
