Characterization of Powder Metal Jet and Penetration Calculation

Abstract

Comprehensive measurements of powder metal jet characteristics, namely the jet density and velocity profiles, have been obtained for a small size shaped charge widely used in the oilfield industry. The results are needed to examine existing penetration models, and to serve as benchmarks for numerical simulations. The jet flash x-ray and digitized images are recorded to measure the density profile, based on measured attenuation characteristics of the liner materials. Results show that density decreases from jet tail to tip, with a weak dependence on time. The results are consistent with previous findings for a similar charge. The jet velocity profile was determined by a series of time-of-arrival (TOA) experiments, using aluminum foil switches embedded in a limestone target. Results show that the jet velocity decreases linearly from tip to tail until the stagnation point. Finally, the measured jet density and velocity profile were applied to Tate-Alekseevskii penetration model to calculate jet penetration in limestone for which compressive strength is available. The calculated penetration time history fit the test data very well, while further work is needed to improve the agreement with penetration velocity.