RA155 Design
Integrated rocket-assisted projectile design workspace.
- Shared physical motor definition
- Projectile and propulsion design studies
- Design-range trade assessment
- Explicit transfer to trajectory and motor modules
BallisticWorkbench
BallisticWorkbench · Integrated engineering environment
From motor physics to trajectory in one workbench
BallisticWorkbench combines projectile and range-extension design, static-firing data reduction, chemical equilibrium, solid-rocket-motor analysis, barrel launch dynamics and trajectory prediction in one connected engineering workflow. Supported trajectory concepts include standard ballistic, base bleed, rocket assist, combined rocket assist + base bleed, ramjet assist and hollow-base configurations.
RA155Base BleedRA + Base BleedRamjet AssistAOP-4355Trajectory & RangeStatic-Firing Burn Rate0D Motor1D Internal FlowErosive Burning1DOF BarrelSpin / Rifling
Motor designShared propellant, grain, burn-law and nozzle definition.
Internal ballistics0D and axially resolved transient 1D analysis.
TrajectoryAOP-4355 trajectory models and integrated RA155 Design & Range analysis.
Engineering workflowExplicit transfers, post-processing, sweeps and export.
Grain design
Named grain geometries and 3D burnback inspection
Named grain families feed the generalized axial representation used by the 1D solver and Grain 3D viewer. Custom axial-section workflows are available for nonuniform and finite-transition configurations.
Named grain geometries
- Tubular
- BATES
- Star
- Finocyl
- Moon Burner
- C-Slot
- Wagon Wheel
- Double Anchor
- Dogbone
- Slot
- Multi-Perforated
- Rod and Tube
- End Burner
- Spherical
Custom geometry: integrated axial-section definitions and imported burnback/source-weight workflows support configurations beyond the named families.
RA155
Rocket-assisted projectile design, packaging and range
The RA155 workspace links the physical projectile definition to interactive 3D packaging, trajectory performance and constrained range optimization in one authoritative design workflow.
Trajectory & munition models
Multiple trajectory formulations and munition concepts
BallisticWorkbench is not built around a single degree-of-freedom trajectory model. The user-facing trajectory environment is centered on AOP-4355 model families together with the integrated RA155 Design & Range workflow, covering conventional, spin-stabilized, propelled, guided, deployment and range-extension problems.
AOP-4355 trajectory models
Point MassTranslational trajectory model with Mach-dependent drag, wind, spherical-Earth gravity and Coriolis treatment.
Modified Point MassSpin-stabilized projectile model with yaw-of-repose, yaw drag, lift, Magnus force and spin damping.
Rocket-Assisted MPMModified Point Mass with delayed rocket thrust, pressure thrust, thrust-on aerodynamics, motor-fuel depletion and changing inertia.
Base-Burn MPM — Method 1AOP base-burn treatment using fuel injection, burn surface, pressure, temperature and projectile spin.
Base-Burn MPM — Method 2Second implemented AOP base-burn formulation available from the same trajectory workbench.
Fin-Stabilized Rocket 5DOFPhased launcher / fins-closed / fins-open five-DOF angular-motion model followed by point-mass coast.
SubmunitionCarrier release and dispersion analysis with selectable submunition type and separation logic.
Aircraft-Dropped PalletFive-phase cargo-drop model covering deck, ramp, free-fall stabilization, parachute inflation and descent.
GPS/INS Guided MPMGuided Modified Point Mass workflow with ballistic, GPS/INS mid-course and terminal guidance phases.
Laser-Guided MPMLaser-guided Modified Point Mass trajectory model within the same AOP-4355 environment.
Range-extension / projectile configurations
Standard / ballisticConventional projectile analysis without active range-extension propulsion.
Rocket AssistRocket-assisted projectile analysis coupled to the common motor definition and ignition controls.
Base BleedBase-bleed treatment with fuel regression, burn-area evolution, spin influence, Mach-dependent injection data and remaining-fuel tracking.
Rocket Assist + Base BleedCombined range-extension configuration with explicit base-bleed / rocket sequencing.
Ramjet AssistSolid-fuel ramjet range-extension configuration with dedicated fuel and cycle treatment.
Hollow Cylindrical BaseHollow cylindrical-base projectile configuration supported by the range-analysis framework.
Hollow Rounded BaseRounded hollow-base projectile configuration supported by the same range-analysis framework.
Constrained range optimizationThe RA155 workflow optimizes design variables and firing elevation subject to engineering constraints such as payload and peak chamber pressure.
Modules
Integrated tools for the complete ballistic workflow
Each module can be used independently, while shared motor and propellant data allow a design to move from characterization to motor simulation and trajectory assessment without duplicating the engineering definition.
AOP-4355
Standardized rocket-assisted projectile trajectory workflow.
- Rocket-assist trajectory calculation
- Physical motor, 0D or thrust-table source
- Ignition and thrust-on controls
- Range and trajectory histories
Chemical Equilibrium
Propellant-gas state and performance-property calculation.
- Equilibrium rocket calculations
- Closed-bomb equilibrium
- Temperature, molecular weight and gamma
- Characteristic-velocity and gas-property outputs
0D Motor
Rapid chamber-pressure and thrust prediction for design iteration.
- Transient or quasi-steady operation
- Shared grain, burn-law and nozzle data
- Pressure and thrust histories
- Trajectory-performance source
1D Internal Flow
Transient axially resolved internal ballistics with evolving grain geometry.
- Quasi-1D finite-volume chamber flow
- Burnback, ignition and erosive burning
- Thermochemistry and throat evolution
- Optional dispersed Al₂O₃ transport
Burn Rate
Burn-law characterization for motor-analysis workflows.
- Saint-Robert / Vieille pressure law
- Single or piecewise regimes
- Temperature sensitivity
- Explicit transfer of accepted burn-law data
1DOF Barrel
One-dimensional launch-state evolution for standard barrel configurations.
- Projectile acceleration
- Pressure-force history
- G-load history
- Spin evolution for rifled barrels
Additional solvers & analysis modules
Dedicated analysis tools beyond the trajectory workspace
BallisticWorkbench includes separate engineering solvers for barrel launch dynamics, static-firing data reduction, equilibrium thermochemistry and fast motor prediction. Their outputs can be transferred explicitly into the higher-level design workflows.
1DOF Barrel Solver
Projectile translation, pressure loading and rifling-driven spin development through the barrel.
- Smoothbore, constant-twist and progressive-twist rifling
- Right-hand or left-hand rifling convention
- Projectile position, velocity and acceleration
- Pressure force and longitudinal G-load histories
- Local twist, spin rate, rpm and angular acceleration
- Muzzle velocity and muzzle spin for downstream trajectory analysis
Burn Rate from Static Firings
Engineering reduction of measured test-motor firing data into propellant regression and fitted burn-law information.
- Imports time / chamber-pressure / thrust firing logs
- Average, P1 or P2 pressure channel and Pa / MPa / bar input
- Automatic or user-selected pressure-reference treatment
- End-burning, cylindrical-core or tabulated burn-area geometry
- Uses consumed propellant mass, throat evolution and ideal c*
- Reconstructs mass flow and burn-rate history
- Optional Saint-Robert/Vieille fit with OLS or robust median-slope regression
- Reports fit pressure range and log-space R²
0D Motor Solver
Compact internal-ballistics solution for rapid motor sizing and performance transfer.
- Transient or quasi-steady chamber solution
- Shared grain, burn-law and nozzle definition
- Pressure, mass-flow and thrust histories
- Free-volume and solver controls
- Performance source for trajectory studies
Chemical Equilibrium
Equilibrium thermochemistry for both propulsion and closed-volume calculations.
- Rocket equilibrium calculation mode
- Closed-bomb equilibrium mode
- Combustion temperature and equilibrium composition
- Gas molecular weight, heat-capacity ratio and thermodynamic properties
- Characteristic velocity and nozzle-related outputs where applicable
AOP-4355
Dedicated trajectory-model workbench spanning conventional, spin-stabilized, propelled, guided and deployment problems.
- Point Mass and Modified Point Mass
- Rocket-Assisted Modified Point Mass
- Base-Burn MPM Methods 1 and 2
- Fin-Stabilized Rocket 5DOF
- Submunition and aircraft-dropped pallet models
- GPS/INS and laser-guided MPM
1D Internal Ballistics
Detailed motor physics with real GUI inspection
The 1D module links grain definition, burnback, ignition, quasi-one-dimensional chamber flow, thermochemistry, throat/nozzle treatment, post-processing and automated parameter studies in the same case.
Physical models and engineering outputs
Pressure-dependent burning and evolving local geometry are solved together with chamber flow and nozzle discharge. Optional modified Mukunda-Paul erosive burning uses the resolved local port mass flux and is available across the generalized grain families. Global histories and axial fields remain linked to the active grain state.
Burning & erosive augmentationSaint-Robert/Vieille law, piecewise pressure regimes, propellant-temperature sensitivity, plus optional modified Mukunda-Paul erosive burning driven by resolved local port mass flux. The correction exposes K1, onset-threshold and gas-viscosity controls and is available across generalized grain families.
IgnitionIgniter gas mass, duration, temperature, injection velocity, source length, ignition delay and flame spread.
Nozzle / throatFixed throat, erosion or prescribed throat-diameter history with discharge and nozzle-efficiency controls.
Axial solutionPressure, temperature, density, axial velocity, Mach number, mass flux, local web, area and burn-rate quantities.
Gas–particle coupled 1D solver
Optional dispersed Al₂O₃ transport with two-way coupling
The 1D internal-ballistics solver can advance a separate condensed alumina phase together with the carrier gas. The particle phase is solved explicitly rather than folded into the gas thermodynamic properties.
Physical treatment
Phase separationEquilibrium chemistry is evaluated first; condensed Al₂O₃ is separated from the gaseous species so carrier-gas molecular weight, R, cₚ and γ remain gas-only.
Particle conservation lawsSeparate conservative particle mass, axial momentum and energy transport are advanced for the dispersed phase.
Interphase momentumSchiller–Naumann drag with equal-and-opposite momentum exchange between gas and particles.
Interphase heat transferRanz–Marshall heat transfer with equal-and-opposite gas/particle energy exchange.
Nozzle treatmentCarrier-gas choking uses gas-only thermodynamic properties; alumina outlet discharge is advanced and accounted separately.
Particle model scopeFixed particle diameter with a 10 μm default. Initial implementation does not include breakup, coalescence or particle-diameter evolution.
Particle results appear only when enabled
The result set remains uncluttered for gas-only cases. When dispersed Al₂O₃ is active, the workbench exposes particle-specific engineering quantities.
- Particle loading
- Particle velocity and temperature
- Particle mass flux
- Particle volume fraction
- Gas–particle slip velocity
- Outlet Al₂O₃ mass flow
- Total two-phase mass-closure diagnostics
Numerical methods
Conservative quasi-1D finite-volume formulation
The numerical formulation is documented explicitly so the motor results are traceable to the spatial discretization, time integration, geometry coupling and two-phase transport model.
Finite volume
Area-weighted conservative variables are advanced for mass, axial momentum and total energy.
- Quasi-1D conservative formulation
- Rusanov / local Lax–Friedrichs interface flux
- First-order reconstruction
- Optional MUSCL–Rusanov reconstruction
Explicit or implicit
Time advancement can be selected to suit the stiffness and operating regime of the case.
- Second-order Runge–Kutta (RK2)
- Backward-Euler implicit integration
- CFL-controlled physical time step
- User-defined maximum time step
Coupled evolving motor
Flow-area changes and local source terms remain coupled to the regressing grain at each axial location.
- Variable-area quasi-1D source terms
- Local propellant gas-generation source
- Evolving port area and burning perimeter
- Exact splitting at finite axial geometry transitions
Robustness and closure
Solver controls and diagnostics expose nonlinear convergence and conservation quality.
- Nonlinear iteration limit
- Convergence tolerance and relaxation
- Positivity and time-step recovery checks
- Global mass-balance diagnostics
- Two-phase equal-and-opposite source conservation
Real application screenshots
Setup, solve and inspect without leaving the workbench
These are direct GUI captures from BallisticWorkbench, not brochure pages or document screenshots.
Workflow
Explicit data flow between engineering models
Thermochemical results, burn-law data and motor-performance sources are transferred explicitly and remain reviewable. BallisticWorkbench avoids silent overwrites between independent analysis modules.
DefineProjectile, motor, grain and propellant.
CharacterizeChemical-equilibrium and burn-rate properties.
Solve motor0D or transient axially resolved 1D analysis.
PropagateAOP-4355 trajectory models or the integrated RA155 Design & Range workflow.
CompareHistories, axial fields, sweeps and exported results.
Verification and validation
Published-data checks for the 1D motor model
The current 1D technical note separates published-data validation from numerical implementation checks. Representative burn-duration comparisons are shown here as concise engineering evidence.
+0.44%BARIA Low burn-duration difference: 4.657 s versus 4.637 s reference.
-0.53%BARIA Medium burn-duration difference: 3.970 s versus 3.991 s reference.
-0.14%BARIA High burn-duration difference: 3.325 s versus 3.329 s reference.
Within rangeHasegawa A: 4.037 s versus published 3.7–4.4 s range.
Within rangeHasegawa B: 4.170 s versus published 3.8–4.5 s range.
Within rangeHasegawa C: 2.306 s versus published 1.7–2.4 s range.
BallisticWorkbench
Integrated ballistic engineering from grain to trajectory
Use one environment for propulsion definition, equilibrium thermochemistry, burn-rate characterization, internal ballistics, launch dynamics and trajectory analysis.
Technical enquiry