System modeling of explosively actuated valves

Document Type

Article

Publication Date

1-1-2007

Abstract

A model is formulated to describe time-dependent operation of an explosively actuated valve. The model accounts for burning of solid explosive to form product gas within an actuator, transport of product gas from the actuator to an expansion chamber, and insertion of an initially tapered piston into a constant diameter bore by gas pressure within the expansion chamber. A cutter attached to the piston punctures a diaphragm enabling the desired gas flow. An important model feature is the coupling of combustion energy to piston-housing deformation resulting from gas pressure and geometric interference during piston insertion. The model is correlated with quasi-static compression tests, and combustion bomb data for the explosive HMX (C4H8N 8O8), that provide estimates for the valve work requirements, and the pressure dependent burning rate, respectively. The model is then used to predict operation of a baseline valve configuration and to assess how variations in explosive mass and valve geometry affect performance. Predictions indicate that 150 mg of HMX routinely used with the baseline valve induces far greater piston kinetic energy than needed for successful operation. The appropriateness of key assumptions about stress and deformation fields within the piston and housing are examined based on a rate-independent finite-element analysis. Copyright © 2007 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.

Publication Source (Journal or Book title)

Journal of Propulsion and Power

First Page

1080

Last Page

1095

This document is currently not available here.

Share

COinS