Pressure signature and evaluation of hammer pulses during underwater implosion in confining environments

2016 ◽  
Vol 140 (2) ◽  
pp. 1012-1022 ◽  
Author(s):  
Sachin Gupta ◽  
Helio Matos ◽  
Arun Shukla ◽  
James M. LeBlanc
Keyword(s):  
Underwater Implosion

scholarly journals Underwater implosion pressure pulse interactions with submerged plates

2020 ◽  
Vol 143 ◽  
pp. 104051
Author(s):  
Shyamal Kishore ◽  
Koray Senol ◽  
Prathmesh Naik Parrikar ◽  
Arun Shukla
Keyword(s):  
Pressure Pulse ◽  
Underwater Implosion

Underwater Implosion Mechanics: Experimental and Computational Overview

2013 ◽  
pp. 161-187 ◽  
Author(s):  
James LeBlanc ◽  
J. Ambrico ◽  
S. Turner
Keyword(s):  
Underwater Implosion

Underwater Implosion of Cylindrical Metal Tubes

2012 ◽  
Vol 80 (1) ◽  
Author(s):  
Stephen E. Turner ◽  
Joseph M. Ambrico
Keyword(s):  
Finite Element ◽  
Near Field ◽  
Radial Distance ◽  
Time History ◽  
Small Scale ◽  
Thin Wall ◽  
Pressure Time ◽  
Gauge Pressure ◽  
Basic Physics ◽  
Underwater Implosion

The basic physics of the underwater implosion of metal tubes is studied using small scale experiments and finite element simulations. A series of underwater implosion experiments have been conducted with thin-wall aluminum alloy 6061-T6 tubes. The nominal tube dimensions are 2.54 cm outside diameter and 30.48 cm length. Two cylinders collapsed at their natural buckling pressure of 6895 kPa gauge pressure (1000 psig). Two additional cylinders were caused to implode at 6205 kPa gauge pressure (900 psig) using an initiator mechanism. Each of the four cylinders failed with a mode 2 shape (collapsed shape is flat with two lobes). The near field pressure time-history in the water is measured at a radial distance of 10.16 cm (4in.) from the centerline at three points along the cylinder's length. The pressure time-histories show very similar behavior between the cylinders which buckled naturally and those which were mechanically initiated at 90% of the buckling pressure. To aid in understanding the physical implosion phenomena, a computational model is developed with a fluid-structure-interaction finite element code (DYSMAS). This model is validated against the experimental data, and it is used to explain the features of the implosion pressure pulse and how it is physically created.

scholarly journals Sympathetic underwater implosion in a confining environment

2015 ◽  
Vol 3 ◽  
pp. 123-129 ◽  
Author(s):  
Sachin Gupta ◽  
James M. LeBlanc ◽  
Arun Shukla
Keyword(s):  
Underwater Implosion

A COMPRESSIBLE LAGRANGIAN FRAMEWORK FOR MODELING THE FLUID–STRUCTURE INTERACTION IN THE UNDERWATER IMPLOSION OF AN ALUMINUM CYLINDER

2013 ◽  
Vol 23 (02) ◽  
pp. 339-367 ◽  
Author(s):  
KAZEM KAMRAN ◽  
RICCARDO ROSSI ◽  
EUGENIO OÑATE ◽  
SERGIO RODOLFO IDELSOHN
Keyword(s):  
Atmospheric Pressure ◽  
Fluid Structure Interaction ◽  
Shell Element ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Lagrangian Framework ◽  
Pressure Water ◽  
Aluminum Cylinder ◽  
Underwater Implosion ◽  
Forward Euler

We propose a fully Lagrangian monolithic system for the simulation of the underwater implosion of cylindrical aluminum containers. A variationally stabilized form of the Lagrangian shock hydrodynamics is exploited to deal with the ultrahigh compression shock waves that travel in both air and water domains. The aluminum cylinder, which separates the internal atmospheric-pressure air from the external high-pressure water, is modeled by a three-node rotation-free shell element. The cylinder undergoes fast transient deformations, large enough to produce self-contact along it. A novel elastic frictionless contact model is used to detect contact and compute the non-penetrating forces in the discretized domain between the mid-planes of the shell. Mesh quality in the vicinity of the cylinder is guaranteed by regenerating the mesh in the air and water domains when large displacements occur. A monolithic fluid–structure interaction (FSI) system is then solved. Two schemes are tested, implicit using the predictor/multi-corrector Bossak scheme, and explicit, using the forward Euler scheme. The results of the two simulations are compared with experimental data.

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