Axisymmetric calculations for the large blast/thermal simulator (Lb/Ts) shock tube configuration. Technical report, January-September 1986

Computational fluid dynamics is a tool that predicts the gas dynamics of blast problems of interest to the Army by solving a set of mathematical equations with a high-speed digital computer. The governing equations for the blast problems presented here are the two-dimensional unsteady Euler equations. The computations were performed on a Cray XMP/48 supercomputer by discretizing the Euler equations with an upwind, Total Variation Diminishing, finite volume, implicit scheme. Details of the scheme are presented. The algorithm is used here to provide gas-dynamic information for a candidate large-scale blast simulator (LBS) concept. A growing need exists for nuclear-blast survivability testing of tactical equipment. In order to meet this need, research is conducting into the design and operation of a Large-scale Blast Thermal Simulator, essentially a large multi-driver shock tube. Experiments with heated and unheated driver gas were performed in a single driver, 1/67-scale model of the LB/TS design concept but without the thermal simulation (LBS). One-dimensional calculations were performed for the 1/67-scale LBS with useful results. However, the one-dimensional calculations have had limited success for accurately predicting the flow through the diverging portion of the LBS design because the flow in this region is multi-dimensional. The flow is multi-dimensionalmore » due to the rapid and large area change that exists in the diverging nozzle. The paper presents results which demonstrate the nature of fluid physics in the 1/57 scale LBS.« less