Axisymmetric Calculations for the Large Blast/Thermal Simulator (LB/TS) Shock Tube Configuration

摘要

Computational fluid dynamics is a tool which 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 in the paper. 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 have been performed in a single driver, 1/67 scale model of the LB/TS design concept but without the thermal simulation (LBS). One dimensional calculations have been 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-dimensional 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. (jhd)