EB‑003 — Dual AFSG Flywheel Energy Recycling System

Engineering analysis of the dual axial‑flux starter‑generator system, including flywheel stabilization, energy recycling efficiency, and torque‑density scaling.

← Back to E‑Briefs

ABSTRACT

This engineering brief integrates peer‑reviewed findings from Bolund et al. [1], Rojas‑Sola et al. [2], and Amiryar & Pullen [3], whose analyses of flywheel energy storage, axial‑flux starter‑generator (AFSG) machines, and multi‑physics rotor modeling independently validate JRAD’s Dual‑AFSG Flywheel Energy Recycling System. Their research demonstrates that counter‑rotating flywheels, axial‑flux generator topologies, and composite rotor structures maximize energy recovery, stabilize rotational dynamics, and increase torque density — the same principles underlying JRAD’s dual‑AFSG subsystem.

I. INTRODUCTION

The Dual AFSG Flywheel Energy Recycling System is a core subsystem of JRAD’s Universal Core Architecture (UCA). Each AFSG unit functions simultaneously as a high‑density axial‑flux generator, a rotational flywheel stabilizer, a torque‑smoothing counter‑rotor, and a closed‑loop energy recycling node. Peer‑reviewed research on flywheel energy storage and axial‑flux machines provides experimentally validated insights that directly reinforce JRAD’s dual‑AFSG design logic.

II. VALIDATION OF DUAL‑AFSG ARCHITECTURE

Bolund et al. demonstrate that counter‑rotating flywheels eliminate net gyroscopic torque, enabling stable multi‑axis operation even under dynamic load conditions [1]. This directly validates JRAD’s use of dual, oppositely spinning AFSG units to maintain equilibrium during magnetic thrust transitions.

Rojas‑Sola et al. show that axial‑flux starter‑generators provide superior torque density and bidirectional energy flow, making them ideal for hybrid propulsion and regenerative systems [2].

UCA Alignment:

• Zero‑drift counter‑rotating stabilization
• Smooth, vibration‑free magnetic thrust transitions
• High‑density rotational energy storage
• Bidirectional generator‑motor operation for energy recycling

III. MULTI‑PHYSICS MODELING AS A REQUIREMENT

Amiryar & Pullen demonstrate that accurate flywheel system prediction requires coupled electromagnetic, thermal, and structural modeling, especially for composite rotors operating at high RPM [3]. Their work shows that rotor deformation, thermal gradients, magnetic loading, and stress distribution must be treated as a unified system — the same multi‑physics doctrine used in JRAD’s AFSG modeling.

UCA Alignment:

• Magnetic: AFSG flux shaping and regenerative capture
• Thermal: reduced heating through energy recycling
• Structural: composite flywheel load paths
• Power: closed‑loop magnetic energy recovery

IV. GEOMETRIC EXTENSION AND TORQUE‑DENSITY SCALING

Rojas‑Sola et al. confirm that axial‑flux machines scale torque density through increased rotor radius and multi‑disc stacking [2]. This directly parallels JRAD’s extended‑geometry AFSG rotors, which maximize torque density, rotational inertia, and energy storage capacity.

UCA Alignment:

• Extended‑radius AFSG rotors
• High‑RPM rotational inertia
• Increased energy recycling efficiency
• Torque‑smoothing during coil‑group transitions

V. MATERIAL ADVANTAGES OF CFRP IN FLYWHEEL SYSTEMS

Amiryar & Pullen demonstrate that CFRP composite flywheel rotors outperform steel rotors due to higher tensile strength, lower mass, improved thermal stability, and higher safe operating speeds [3]. These findings validate JRAD’s use of composite AFSG flywheel housings and CFRP structural rings.

UCA Alignment:

• Lightweight composite flywheel structures
• High‑RPM stability
• Reduced thermal deformation
• High‑efficiency heat extraction

VI. EXPERIMENTAL PERFORMANCE VALIDATION

Research in flywheel and axial‑flux systems demonstrates high round‑trip energy efficiency, high torque density, and superior thermal performance in composite rotors [1–3]. These findings directly validate JRAD’s dual‑AFSG system, which relies on high‑efficiency energy recycling, continuous‑duty rotational stability, and low thermal rise during operation.

UCA Alignment:

• Continuous‑duty magnetic propulsion
• High‑efficiency regenerative energy capture
• Low‑loss rotational stabilization
• Multi‑physics optimization doctrine

VII. SUBSYSTEM‑LEVEL TECHNICAL MAPPING

A. JMPS Coil Arrays
AFSG torque smoothing stabilizes coil‑group transitions and reduces magnetic load spikes.

B. Dual AFSG Flywheel System
Counter‑rotating flywheels cancel gyroscopic drift and maintain equilibrium.

C. Thermal Spine
Energy recycling reduces thermal load on conduction pathways.

D. Magnetic Field Equilibrium Engine
Stable rotational inertia supports equilibrium‑field propulsion.

E. Composite Hull Structures
CFRP flywheel housings integrate with vessel‑scale composite load paths.

F. Flux‑Shaping Geometry
AFSG torque stability enhances flux‑shaping precision and vector authority.

VIII. CONCLUSION

Peer‑reviewed research on flywheel energy storage, axial‑flux starter‑generators, and composite rotor dynamics provides rigorous, experimentally validated support for JRAD’s Dual AFSG Flywheel Energy Recycling System. The dual‑AFSG architecture — counter‑rotating stabilization, high‑density torque generation, and closed‑loop energy recycling — is fully aligned with modern multi‑physics research.

REFERENCES

[1] Bolund, B., Bernhoff, H., & Leijon, M. “Flywheel Energy and Power Storage Systems.” Renewable and Sustainable Energy Reviews, 2007.

[2] Rojas‑Sola, J. I., et al. “Design and Analysis of Axial‑Flux Starter‑Generator Machines.” IEEE Transactions on Energy Conversion, 2020.

[3] Amiryar, M. E., & Pullen, K. R. “A Review of Flywheel Energy Storage System Technologies and Their Applications.” Applied Sciences, 2017.