Date of Award

2026

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Mechanical Engineering

Committee Chair

Nicholas Ginga

Committee Member

Jason Cassibry

Committee Member

Nathan Spulak

Committee Member

Robert Frederick

Committee Member

Phillip Mulligan

Research Advisor

Nicholas Ginga

Subject(s)

Shaped charges--Mathematical models, Jets--Fluid dynamics

Abstract

This effort investigates and details the collapse and jet formation process of a constant wall thickness hemispherical shaped charge liner. Upon interaction with a detonation wave, liner elements are ejected and converge toward an assumed uniform collapse location. By conserving mass, momentum, and treating the liner as an incompressible perfect fluid, a novel set of equations to predict the characteristics of a layered jet is presented. The use of Gurney formulas to describe the initial collapse velocity of a liner enables a fully self-contained, analytic method for predicting jet properties originating from a hemispherical-lined shaped charge. A base theory describing collapse and jet formation following liner interaction with a planar detonation wave is first presented. Here, the set of equations is evaluated against a matrix of continuum-based simulations with varying geometric dimensions to quantify the model’s accuracy and determine ranges of validity. The influence of liner material strength on jet characteristics is also examined, resulting in an empirically based method to consider these effects. Use of this empirical method is found to result in sufficient descriptions relative to more physically representative simulations employing a liner material strength definition. The base model is then adapted to consider liners collapsing due to interaction with a point-initiated detonation wave. This set of modified equations is then compared to results from two physical test events and further evaluated against a matrix of continuum-based simulations consisting of charges with differing geometric dimensions and varying initiation locations. When collapse velocity profiles are accurately characterized in both trend and magnitude, analytic jet predictions closely agree with simulations that neglect liner material strength for nearly all plane-wave and point-initiated charges examined in this study. This agreement is demonstrated by an average coefficient of determination (R²) of 0.92 and a mean absolute error (MAE) of ±0.23 km/s across nearly all analytic jet predictions that fall within the model’s applicable ranges. These comparisons span a broad range of charge dimensions, liner and explosive materials, and initiation schemes and locations. Collectively, these results underscore the importance of accurately characterizing the collapse velocity profile and support the validity of the equations developed in this work. Although further refinement is needed, the results indicate that the concepts presented here offer a viable approach for analytically predicting jet characteristics across much of the trade space available to shaped charge designers, thereby supporting their application in research, design, and real-world settings.

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Available for download on Wednesday, November 04, 2026

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