System Modeling for Projectile Design and Optimization Presented By : Phil Brislin

System Modeling for Projectile Design and Optimization Presented By : Phil Brislin

AGENDA What is EAPS? Development of a projectile design model. Algorithm description. Benefit to the EAPS program.

Extended Area Protection & Survivability (EAPS) Aerial defense system against Rockets, Artillery, and Mortars (RAM) threats. Two year ARDEC Advanced Technology Objective (ATO) ending in a demonstration of critical technologies including: course correction, lethality, and command warhead detonation. Provide future defeat capability for the Extended Area Air Defense System (EAADS) comprised of 360 degree mobile RAM defense.

EAPS Baseline System Concept 50mm Bushmaster Cannon RF Data Link Radar Track 10 Round Burst Mid-Flight Course Correction Forward Fragmentation Warhead Detonation 50mm Course Corrected Projectile

Design Challenges and Goals The EAPs bullet has a number of difficult performance objectives that often have conflicting subsystem goals and limited available space. The system trade study provided a list of projectile requirements. What are the best projectile subsystem design compromises that will give maximum overall system performance? Develop one comprehensive model to evaluate projectile performance and find the best design space to begin detailed design.

Merging Requirements and Design Constraints 1000m Range System Performance Requirements Flow Down Examples Lethal Fragments Pattern Density Strike Velocity 50mm Trade Study Results Thruster Matlab Configuration Study Aerodynamics Optimized Projectile Framework to Begin Detailed Design Design Constraints Examples Mass Properties / CG Survivability (Stress) Material Properties Propulsion Data Collect Inputs from Design Groups Warhead Formation

Understand the EAPS System 50mm System Exterior Projectile Profile Material Selection ICD FEA / Payload Volume Max Pressure Case Volume Fin / Boom Design Structural Airframe Design Electronics / Thruster Interior Volume Electronics / Thruster Packaging Design Propellant Volume Projectile Mass Warhead Center of Gravity Muzzle Velocity Thruster Size / Impulse Drag Characteristics 1500m Velocity Nose Cone Profile Combined Strike Velocity Stability Accuracy Target Defeat

Implement a Solver Method Design Space Challenges Numerous invalid variations exist causing convergence issues. Analytic solution methods difficult to implement and adapt. Ex - High Velocity Variation Ex - Large Warhead Sweet Spot Invalid Solutions Ex Good Performer

Matlab Configuration Study Video

Algorithm Description Requirements & Variable Inputs Interior Ballistics & Survivability Exterior Ballistics & Lethality Requirements Check, Ranking & Summary Requirements - Strike velocity, center of gravity, max weight, etc. Generates geometry & assembles components Calculates or integrates mass properties (Pro E verified).

Algorithm Description Requirements & Variable Inputs Interior Ballistics & Survivability Exterior Ballistics & Lethality Requirements Check, Ranking & Summary Interior Ballistics and Survivability Load max charge allowable IBHVG2 data for max pressure and velocity Stress checks throughout the projectile Current Iteration (n) Boom Profile Projectile Mass * IBHVG2 Data Case Volume Propellant Mass Calculate Breech Pressure P>72ksi Calculate New Max Charge Weight P<72ksi P<72ksi Calculate Muzzle Velocity & Gs Calculate Muzzle Velocity & Gs

Algorithm Description Requirements & Variable Inputs Interior Ballistics & Survivability Exterior Ballistics & Lethality Requirements Check, Ranking & Summary Flight Dynamics Determines velocity falloff for every unique configuration. Lethality Determines warhead velocity (based on Dyna and CTH runs). Calculates maximum effective range for target defeat.

Algorithm Description Requirements & Variable Inputs Interior Ballistics & Survivability Exterior Ballistics & Lethality Requirements Check, Ranking & Summary High muzzle velocity Failed stress check Exceeds electronics G limit Warhead velocity insufficient Poor thruster location Very low muzzle velocity Exceeds max weight High warhead velocity

Study Output Summary

Additional Examples of Results 30 EAPs Projectile Configurations (Common Traits) WARHEAD CONFIGURATION EFFECT ON LETHAL RANGE Requirement MEFP DF MEFP Liner Mass DF Liner Mass Number of Optimized Runs 25 20 15 10 5 1 2 3 Lethal Range (m) Liner Mass (g) 0 Boom Ogive Aft Material Warhead Thickness Warhead Matereal Projectile Mass # of MEFP Solid System Understanding MEFP Configuration Comparison Velocity (m/s) 5 MEFP 7 MEFP 12 MEFP 13 MEFP 14 MEFP 16 MEFP 19 MEFP 21 MEFP Ground Range (m)

Summary Level of fidelity and resolution of system modeling is time dependent. EAPS study provided an excellent first cut design for a 4 month time frame. EAPS subsystem design requirements established with modeling. Avoiding the sequential design method saved at least 4 months and ~$200k.

QUESTIONS?