We consider application of higher-order schemes to the Boltzmann model equations with a goal to develop a deterministic computational approach that is accurate and efficient for simulating flows involving a wide range of Knudsen numbers. The kinetic equations are solved for two non-equilibrium flow problems, namely, the structure of a normal shock wave and an unsteady two-dimensional shock tube...

form of a primary blast wave) that occurs when a powerful explosive detonates in a free field, without nearby surfaces that can interact with the wave. A series of complex shock waves are then generated following the lead shock wave (the original shock front), including reflected shock waves, a Mach stem, an unsteady turbulent jet, and rarefaction waves. These waves can cause sudden compression...

Two-dimensional Direct Simulation Monte Carlo (DSMC) simulations are carried out for investigating the shock wave propagation and boundary layer effects in a shock tube flow, for a wide range of rarefied conditions. Nitrogen is used for all simulations. The Cercignani-Lampis-Lord (CLL) model of gas surface interactions is implemented to study the effects of boundary layer which develops behind ...

This work is to develop an experiment-validated numerical model to elucidate the wave transmission mechanisms through a surrogate head under blast loading. Repeated shock tube tests were conducted on a surrogate head, i.e., water-filled polycarbonate shell. Surface strain on the skull simulant and pressure inside the brain simulant were recorded at multiple locations. A numerical model was deve...

Exposure to blast events can cause severe trauma to vital organs such as the lungs, ears, and brain. Understanding the mechanisms behind such blast-induced injuries is of great importance considering the recent trend towards the use of explosives in modern warfare and terrorist-related incidents. To fully understand blast-induced injury, we must first be able to replicate such blast events in a...

We establish the equivalence of free piston and delta shock, for one-space-dimensional pressureless compressible Euler equations. The shock appearing in singular Riemann problem is exactly that may move freely forward or backward a straight tube, driven by flows on two sides it tube. This result not only helps to understand physics somewhat mysterious shocks, but also provides way reduce fluid-...