Exploratory Analysis of Helium Layer Usage for Dynamic Pressure Enhancement inthe Large Blast/Thermal Simulator

摘要

Numerical simulations of the time dependent flow in the Large Blast/ThermalSimulator (LB/TS) were executed to model a possible use of that facility for enhancing dynamic pressure using a helium layer positioned on the floor of the expansion tunnel. The simulations were performed using a 2-D, finite difference Euler equation solver with multiple material models. The flow structure and recorded flow history data for the simulation, employing a single helium layer, are compared to the results of a calculation without a helium layer in order to quantify the dynamic pressure enhancement produced by the presence of the helium layer. The results of the calculations show that the greatest enhancement in dynamic pressure impulse is approximately a factor of two over the case with no helium layer but is limited to a region less than 1 meter from the floor of the expansion tunnel. This limited region of dynamic pressure enhancement is insufficient for blast testing of full scale military vehicles and equipment.