Session: HT-02-02 Impulsively Loaded Vessels - 2

Paper Number: 105749

105749 - Numerical Simulations of the Dynamic Response of Gas Handling Manifolds Mounted on an Impulsively Loaded Confinement Vessel 

A new vessel system is being developed for performing small‑scale shock‑physics experiments in a proton beam imaging facility at the Los Alamos National Laboratory (LANL).  The Inner Pressure Confinement Vessel (IPCV) is the impulsively loaded vessel that confines the detonation products from the experiment and provides access for the proton beam, and other diagnostics, to interrogate the dynamic event.  The products of detonation, that are either in a gaseous state or a solid state, are confined within the IPCV.  The gaseous products are to be vented from the IPCV prior to allowing personnel to reenter the experiment area and be in close proximity to the IPCV.

The IPCV is connected to the overall gas handling system, known as the Vessel Gas Handling System (VGHS) via three independent manifold assemblies.  Each manifold is operated remotely to allow for the venting of the gaseous products in the IPCV prior to personnel entering the experiment area.  The three independent manifolds are each of a different design configuration.  Two manifolds serve to vent the IPCV inner volume, and the third serves to handle gas for the experiment assembly that is mounted inside of the IPCV.  After the execution of the experiment the third manifold may also function as a vent pathway for IPCV internal gaseous products.  A high‑pressure isolation valve is included in each of the manifolds, near the connection point to the IPCV.  Each isolation valve contributes to the confinement role of the IPCV because it seals against any gas flowing further into the VGHS during and after the time of the explosive charge detonation.  Each valve is connected to the top cover of the IPCV using high‑pressure rated fittings and rigid tubing.  Each manifold receives a significant portion of the impulsive load that is reacted by the top cover because each manifold is rigidly connected to the top cover.  Within each manifold assembly the section joined to the top cover, up to the isolation valve, receives both the internal gas pressure pulse as well as the residual shock structural loading that results from being rigidly connected to the IPCV.  The balance of each manifold assembly receives only the residual shock structural loading that results from being rigidly connected to the IPCV.

The basic design requirement for the VGHS manifolds is to meet the requirements of the standard ASME B31.3, Process Piping.  ASME B31.3 in turn allows for analyzing unlisted components to the requirements of the ASME Boiler and Pressure Vessel Code, Section VIII, Division 2, or designated as ASME VIII‑2.  Each IPCV VGHS manifold assembly is analyzed per ASME VIII‑2 for its impulsive loading response because all components are unlisted for this loading regime.  This paper reports on the simulation effort performed to predict the dynamic response of the manifold assemblies to the impulsive loading environment of the IPCV.

Presenting Author: Robert Valdiviez Los Alamos National Laboratory

Presenting Author Biography: Mr. Robert Valdiviez has over 39 years of experience as a practicing mechanical engineer. His experience in structural dynamics is a result of working for over 20 years with extreme loads being placed on structures of various types and sizes, primarily in explosively driven systems. Mr. Valdiviez also has extensive experience in heat and mass transfer systems through his work in industrial and developmental types of equipment.

Throughout his career of approximately 36 years of employment with various U.S. government contractors, and now working in his own engineering consulting firm for over 3 years, Mr. Valdiviez has performed many technical tasks in mechanical engineering applications across the broad areas of structural mechanics and thermal/fluid mechanics. He holds BSME and MSME degrees, and is a registered professional engineer in the states of California and Washington.

Authors:

Robert Valdiviez Los Alamos National Laboratory
Dusan Spernjak Los Alamos National Laboratory
Jesse Scarafiotti Los Alamos National Laboratory