Calhoun: The NPS Institutional Archive Faculty and Researcher Publications Faculty and Researcher Publications Collection 2013 Enhanced performance from insensitive explosives Brown, Ronald Monterey, California. Naval Postgraduate School 2013 Insensitive Munitions and Energetic Materials Technology SymposiumPaper 16169 http://hdl.handle.net/10945/47519 Approved for Public Release ENHANCED PERFORMANCE FROM INSENSITIVE EXPLOSIVES Ronald Brown, John Gamble, Dave Amondson, Ronald Williams, Paul Murch, and Joshua Lusk Physics Department Naval Postgraduate School, Monterey, CA 93943 Contact: [email protected] 2013 Insensitive Munitions and Energetic Materials Technology Symposium Paper 16169 Approved for Public Release Acknowledgement Dr. Kevin Vandersall Lawrence Livermore National Laboratory Technical Staff ANSYS-AUTODYN Berkeley, CA 2013 Insensitive Munitions and Energetic Materials Technology Symposium Paper 16169 Approved for Public Release Projected 14 Demonstrated Levels of Increase 12 “ONC” = Octanitrocubane “N8” = Octaazacubane > - e Overview of s c a e 10 e s r / c > - Achievements n m I e k s , a y e t i Relative to 8 r c c o n l I e V n o 6 i t Explosives a n o t Chronology e D 4 2 0 TNT RDX HMX CL-20 ONC N8 IMX HPX HPX+ 2013 Insensitive Munitions and Energetic Materials Technology Symposium Paper 16169 Approved for Public Release OUTLINE • Objective • Background • Modeling & Validations • Effect of Detonation Convergence on Energy Partitioning • Coaxial Initiation Limitations • Results of Novel Dynamic Compression • Conclusions 2013 Insensitive Munitions and Energetic Materials Technology Symposium Paper 16169 Approved for Public Release Develop means for enhancing directed energy from explosive weapon systems by exploiting the effects of overdriven detonation. Explore means for overcoming the limitations of coaxial charges. Validate prediction techniques. GOAL & OBJECTIVES 2013 Insensitive Munitions and Energetic Materials Technology Symposium Paper 16169 Approved for Public Release Pre-Compression Leads to Elevated Shocked States & Detonation Condition 2013 Insensitive Munitions and Energetic Materials Technology Symposium Paper 16169 Approved for Public Release Equation of State & Modification Agreements with • PBXN-111 PBXN-110/PBXN-111 CYLEX • PBXN-111 Detonation • PBHMX spherical implosion VALIDATION OF PREDICTION TECHNIQUES & TECHNOLOGY BACKGROUND 2013 Insensitive Munitions and Energetic Materials Technology Symposium Paper 16169 Approved for Public Release JWL and JWL-M Equations of State & Concurrence with PBXN-111 CYLEX 2013 Insensitive Munitions and Energetic Materials Technology Symposium Paper 16169 Approved for Public Release CLASSIC CO-AXIAL EXPERIMENT & AGREEMENT WITH SKIDMORE-HART MODEL 2013 Insensitive Munitions and Energetic Materials Technology Symposium Paper 16169 Approved for Public Release SUSTAINED EFFECT OF CIRCUMFERENTIAL INITIATION ON PBXN-111 (INITIATION BY THIN SLEEVE OF PBXN110 AND PBXN-112) Position PBXN- 111 PBXN- 110/111 PBXN- 112/111 (mm) Predict Exp’t Predict Exp’t Predict Exp’t 63.5 7.0 6.3 8.3 8.1 8.4 8.3 44.5 6.5 6.0 8.3 8.2 8.5 9.2 Centerline 5.8 5.5 9.7 10.4 9.9 10.2 Average 6.2 5.8 9.1 9.4 9.3 9.5 2013 Insensitive Munitions and Energetic Materials Technology Symposium Paper 16169 Approved for Public Release HYDRO-CODE PREDICTION COMPARISON WITH REPORTED EXPERIMENTAL DATA: SPHERICAL IMPLOSION Simulation 2013 Insensitive Munitions and Energetic Materials Technology Symposium Paper 16169 Approved for Public Release Effect of Sleeve Thickness 9000 8000 Explosive Sleeve Detonation Casing 7000 Thickness Velocity Velocity PBXN-110 (mm) (m/sec) (m/sec) 6000 PBXN-111 0 5775 1280 5000 2 8303 1403 5 8318 1410 4000 10 8314 1495 13 8320 1549 Velocity, mm/sec Velocity, 3000 20 8317 1647 PBXN-110 25.4 8320 1610 2000 1000 PBXN-111 0 0 5 10 15 20 25 30 PBXN-110 Sleeve Thickness, mm 2013 Insensitive Munitions and Energetic Materials Technology Symposium Paper 16169 Approved for Public Release Relative Energies 2013 Insensitive Munitions and Energetic Materials Technology Symposium Paper 16169 Approved for Public Release Dynamic Compression Technique Results from Circumferential Initiation at ~11 km/sec with core explosives: • High performance HMX-based explosive (“HPX) • Extremely insensitive rubber-based explosive (“IMX”) Diagnostics for Measuring • Convergent front shape • Detonation velocity • Cylinder expansion EXPERIMENTS CONDUCTED WITH INITIATING DEVICE THAT OVERCOMES THE COAXIAL CHARGE LIMITATION 2013 Insensitive Munitions and Energetic Materials Technology Symposium Paper 16169 Approved for Public Release CYLINDER EXPANSION 2013 Insensitive Munitions and Energetic Materials Technology Symposium Paper 16169 Approved for Public Release Charge Setup and Exterior Instrumentation 2013 Insensitive Munitions and Energetic Materials Technology Symposium Paper 16169 Approved for Public Release Case Expansion: Simulation vs Experimental From Implosion Shock SymmetryAUTODYNWave of Case Reflection Case Expansion ExpansionSimulation Confirmed From Sleeve Explosive From Core Explosive 2013 Insensitive Munitions and Energetic Materials Technology Symposium Paper 16169 17 Approved for Public Release CONVERGENT FRONT GEOMETRY & DETONATION VELOCITY 2013 Insensitive Munitions and Energetic Materials Technology Symposium Paper 16169 Approved for Public Release CONFIRMATION OF PREDICTED FRONT GEOMETRY Front Geometry Confirmation DTateasste t2 1 DaTtaessett 32 Distance Time of Height from arrival Height Distance from Time of (mm) Center (mm) (µs) (mm) Center (mm) arrival (µs) 177.8 20.5 36.4 178.3 20.7 36.9 127.8 21.0 42.2 129.6 20.2 42.5 Posi on 1 118.5 40.0 42.3 119.2 40.0 42.4 79.3 21.5 46.7 80.5 20.2 47.2 74.9 31.0 46.9 75.8 29.8 47.1 Posi on 2 69.4 41.0 46.9 70.2 39.5 47.0 30.8 21.0 51.2 30.7 20.4 51.9 25.6 31.5 51.5 25.6 31.0 51.7 Posi on 3 Embedded Structure 20.1 41.5 51.4 20.7 39.8 51.7 With Piezoelectric Sensors Average detonation velocity (3 experiments and 5 measurement, 10.8 ± 0.1 km/sec 2013 Insensitive Munitions and Energetic Materials Technology Symposium Paper 16169 Approved for Public Release Diagnostics 1 μs “0” time 410 μs into event 0 1 2 34 5 6 Direct Image Ghost Image x-axis 2013 Insensitive Munitions and Energetic Materials Technology Symposium Paper 16169 Approved for Public Release RESULTS OF IMX EXPERIMENTS Shot Center 1.905 cm 3.810 cm Average Number Fiber Fiber Fiber Detonation EXPERIMENTEXPERIMEN WITHT 2 – 66.5.5 ”in W CHARGEARHEAD Detonation Detonation Detonation Velocity Velocity Velocity (km/ Velocity (km/s) Detona on velocity increased from (km/s) s) (km/s) Detonation Velocity Increase from 6.2 km/s to 10.2 km/s 6.2 to 10.2 km/sec 1 10.3 10.0 10.1 10.1 DetonationDetona o nFront front Angle52 deg 52ree Degreess 2 10.3 10.1 10.6 10.3 AUTODYN 10.9 10.2 10.1 10.3 Shot Center 1.905 cm 3.810 cm Average ” Number Fiber Fiber Fiber Detonation EXPERIMENTEXPERIMENT WITH3 – 7. 07.0 W inA CHARGERHEAD Detonation Detonation Detonation Velocity Velocity Velocity (km/ Velocity (km/s) DetonationDetona on v Velocityelocity in Increasecreased f rfromom (km/s) s) (km/s) 6.26.2 ktom /10.s to km2/sec 10.1 km/ s Detonation Front Angle 56 Degrees Detona on front 57 degrees 1 10.7 9.5 9.7 10.0 2 10.5 No data 10.0 10.2 *Manganin Gages saturated due to pressures in excess of 0.5 Mbar at the end of the charge AUTODYN 10.9 10.1 10.2 10.4 2013 Insensitive Munitions and Energetic Materials Technology Symposium Paper 16169 Approved for Public Release 1600 1400 1200 Peak Peak Pressu11000r0e0 0 Pressu(krbea r) 800 Overview of (kbars) 600 Achievements 400 Relative to 200 0 TNT RDX HMX ONC CL-20 TNTT HPPN LX-20 IM Max TNT RDX HMX ONC CL-20 TNTT HPPNSl HapPXper Sl IMXapper PROJ Explosives 16 14 Chronology 12 Det. 10 Velocity 8 Also PBXN-111 (km/s) 6 UD, 5.5 to 8.9 4 Ppeak, 12 to 66 GPa 2 0 TNT RDX HMX ONC CL-20 TNTT HPPN LX-20 IM Max TNT RDX HMX ONC CL-20 TNTT HPPNSl HaPXppe r Sl IMXapp e r PROJ 2013 Insensitive Munitions and Energetic Materials Technology Symposium Paper 16169 Approved for Public Release New Model for Sustained Overdriven Detonation 2013 Insensitive Munitions and Energetic Materials Technology Symposium Paper 16169 Approved for Public Release CONCLUSIONS • Substantial increases in velocity and peak pressure in the detonation of existing explosives by dynamic compression effects from circumferential initiation. – Aluminized explosives (PBXN-111) – High performance HMX-based explosive (“HPX”) – Extremely insensitive explosive (“IMX”) • Gains exceed those of on-going and projected chemistry (conventional initiation) and further gains are possible. • Technology can easily be incorporated into weapon systems. • Prediction techniques validated across a wide range of applicable conditions. 2013 Insensitive Munitions and Energetic Materials Technology Symposium Paper 16169 Approved for Public Release Immediate Recommendations • Supra-pressure shock response characterizations of candidate explosives over much greater ranges in order to reach 3+ megabar. • Techniques for detecting pressures in the megabar range required for continued prediction confidence and to explore effects of the pressure continuum across convergent fronts. • Additional exploration and extension of detonation theory. • Exploratory development for enhancing directed energy warheads. 2013 Insensitive Munitions and Energetic Materials Technology Symposium Paper 16169 Approved for Public Release Pressure30 usec: (P andmajor-p vectoreak forwa contoursrd of Pminor pabouteak) a convergent34 usec: (Pm machajor-peak fstemollows of Pminor peak) QUESTIONS 2013 Insensitive Munitions and Energetic Materials Technology Symposium Paper 16169 .