Reactive armor panels have been used for many years as very efficient add-on armor against shaped charge warheads. The main features of the defeat mechanisms of the armor are therefore well known. The origin of the irregular disturbances on the shaped charge jet, which leads to the severe fragmentation and scattering of the jet, is however not described in literature. As this scattering of the jet provides the main protection mechanism of the armor, it is of interest to understand the details of the interaction and the origin of the disturbances. Some experimental observations have been made showing that the backward moving plate often displaces the jet relatively smoothly while it is the interaction with the forward moving plate that causes the disturbances that leads to fragmentation and scattering of the jet. In this work, a mechanism for the interaction is proposed based on the theory of Kelvin–Helmholtz instabilities, which explains the origin of the disturbances on the jet due to the interaction with the forward moving plate. Numerical simulations have been performed to show the difference in the mechanisms of backward and forward moving plates when interacting with the jet. The impact angle of the plate seems to be the dominant parameter for the onset of instabilities. A parametric study has also been performed on how different interaction and material parameters influence the development of instabilities of the interface between the jet and the armor plate. The parametric study shows that low-strength jets promote development of instabilities, a tendency that is amplified by frictional forces between the materials. The influence of the plate strength is more complex due to the influence of the structural stability on the contact forces. The effect of friction and melting of the metals in the boundary layer to the development of the instabilities is discussed. A microscopic study of the edge of the penetration channel has been made, which shows that the materials have been melted during the interaction between the plate and the jet.
Skip Nav Destination
e-mail: helte@foi.se
Article navigation
September 2010
Research Papers
The Role of Kelvin–Helmholtz Instabilities on Shaped Charge Jet Interaction With Reactive Armor Plates
Andreas Helte,
Andreas Helte
Defence & Security, Systems and Technology Division,
e-mail: helte@foi.se
FOI, Swedish Defence Research Agency
, Grindsjön, SE-147 25 Tumba, Sweden
Search for other works by this author on:
Ewa Lidén
Ewa Lidén
Defence & Security, Systems and Technology Division,
FOI, Swedish Defence Research Agency
, Grindsjön, SE-147 25 Tumba, Sweden
Search for other works by this author on:
Andreas Helte
Defence & Security, Systems and Technology Division,
FOI, Swedish Defence Research Agency
, Grindsjön, SE-147 25 Tumba, Swedene-mail: helte@foi.se
Ewa Lidén
Defence & Security, Systems and Technology Division,
FOI, Swedish Defence Research Agency
, Grindsjön, SE-147 25 Tumba, SwedenJ. Appl. Mech. Sep 2010, 77(5): 051805 (8 pages)
Published Online: July 1, 2010
Article history
Received:
August 12, 2009
Revised:
November 25, 2009
Posted:
May 10, 2010
Published:
July 1, 2010
Online:
July 1, 2010
Citation
Helte, A., and Lidén, E. (July 1, 2010). "The Role of Kelvin–Helmholtz Instabilities on Shaped Charge Jet Interaction With Reactive Armor Plates." ASME. J. Appl. Mech. September 2010; 77(5): 051805. https://doi.org/10.1115/1.4001738
Download citation file:
Get Email Alerts
Sound Mitigation by Metamaterials With Low-Transmission Flat Band
J. Appl. Mech (January 2025)
Deformation-Dependent Effective Vascular Permeability of a Biological Tissue Containing Parallel Microvessels
J. Appl. Mech (January 2025)
Mechanics of a Tunable Bistable Metamaterial With Shape Memory Polymer
J. Appl. Mech (January 2025)
Related Articles
Application of the Conservation Element and Solution Element Method in Numerical Modeling of Three-Dimensional Heat Conduction With Melting and/or Freezing
J. Heat Transfer (December,2004)
Simulation of Material Flow and Heat Evolution in Friction Stir Processing Incorporating Melting
J. Eng. Mater. Technol (October,2012)
Local, Instantaneous Heat Transfer Coefficients for Jet Impingement on a Phase Change Surface
J. Heat Transfer (May,1996)
Modeling Wall Film Formation and Breakup Using an Integrated Interface-Tracking/Discrete-Phase Approach
J. Eng. Gas Turbines Power (March,2011)
Related Proceedings Papers
Related Chapters
Numerical Study on Dynamic Discharging Performance of Packed Bed Using Spherical Capsules Containing N-Tetradecane
Inaugural US-EU-China Thermophysics Conference-Renewable Energy 2009 (UECTC 2009 Proceedings)
Numerical Study on Dynamic Charging Performance of Packed Bed Using Spherical Capsules Containing N-Tetradecane
Inaugural US-EU-China Thermophysics Conference-Renewable Energy 2009 (UECTC 2009 Proceedings)
Relation Between Microstructure and Hydrogen: Consequence on the Fatigue Behavior of Laser Beam Melting Inconel 718
International Hydrogen Conference (IHC 2016): Materials Performance in Hydrogen Environments