CEL Blast Wave Propagation Code for Air Ducts

Abstract : Refinement of a CEL hydrodynamic code for prediction of air blast propagation in variable area ventilation ducts was completed. Code solutions are one-dimensional and achieved using a refined finite-difference pseudo-viscosity method in a Lagrange formulation for solution of either classical nuclear blast waves or general time variant pressure waves. Solutions for a single constant area duct with the effects of viscosity at the wall are included. An example case is presented with a description of the single duct geometry, the applied nuclear blast parameters, and the code input parameters, including their magnitudes and their sources. A 2-m-diam duct with a length of 200 meters subject to a side-on 1,000 psi overpressure is analyzed, and the time histories of the blast parameters are presented for three locations in the duct. The effects of wall friction are demonstrated graphically for friction factors of 0. 016 and 0.030. Sequential application of the code to each duct in a branched duct system provides solutions for complex air entrainment systems. A description of the modified CEL Blast Wave Propagation Code basic functions, input quantities, formats and outputs (including a sample input data card listing), input data listing, and an output listing sample are appended.