Accession Number : ADA131581

Title :   Asymmetric Collapse of LOS (Line-of-Sight) Pipe -- LS-5.

Descriptive Note : Final rept. 1 Mar 81-1 Mar 82,

Corporate Author : PHYSICS INTERNATIONAL CO SAN LEANDRO CA

Personal Author(s) : Mumma,D ; Thomsen,J ; Funston,R ; Moore,E T , Jr

PDF Url : ADA131581

Report Date : 01 Mar 1982

Pagination or Media Count : 64

Abstract : This report describes results of a laboratory experiment, designated LS-5, performed to further evaluate the feasibility of using asymmetries to suppress jetting in line-of-sight (LOS) pipes collapsed by the ground shock from an underground nuclear test. Underground conditions were simulated using a sphere of high explosive to collapse small-scale LOS models embedded in saturated sand. Three tapered models were evaluated to determine the sensitivity of jet flow to the degree of taper. Several asymmetries were tested, including a model of the LOS pipe planned for HURON LANDING. Straight LOS pipe models were also tested with various internal helix and ring asymmetries to provide insight into the mechanisms that make these particular designs so effective in attenuating the penetrating jet material. Aluminum witness plates at the end of the tapered LOS pipe models showed ring-like penetration craters, increasing in diameter with increasing pipe taper. The volume of the target craters was almost constant, even when the taper angle was increased by a factor of four, and this volume was within the spread of volumes measured on witness plates from straight pipe models. Addition of a helix, including that of the HURON LANDING configuration, reduced crater damage; however, the benefit was not as dramatic as that observed for straight pipes, and it decreased as the taper angle increased. Crater damage, ring-like for tapered models without helical asymmetries, was more axial when helices were used.

Descriptors :   *Jet flow, *Nuclear explosion simulation, *Pipes, Line of sight, Suppression, Damage assessment, Attenuation, Particulates, Taper, Helixes, Rings, Symmetry, Asymmetry, Craters, Ground shock, High explosives, Underground explosions, Scale models, Sand, Collapse

Subject Categories : Test Facilities, Equipment and Methods
      Explosions
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE