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References & Validation

The SPARK simulator is built upon a foundation of rigorously validated, peer-reviewed scientific literature and aerospace engineering technical reports. To ensure industrial-grade credibility, the physical, electrochemical, economic, and climatic models used throughout the codebase have been cross-referenced with state-of-the-art research from NASA, Cranfield University, and the European Clean Sky 2 program.

Below is the curated bibliography mapping the eight core foundational papers to the simulator's four main modeling pillars.

1. Flight Physics & Aerodynamics (Pillar 1)

The aerodynamic sizing, thrust-drag formulations, and propulsive efficiency models in core/environment.py and core/aircraft.py are heavily based on industry-standard conceptual design approaches for electrified aircraft.

  • Brelje, B. J., & Martins, J. R. R. A. (2018). Electric, hybrid, and turboelectric fixed-wing aircraft: A review of concepts, models, and design approaches. Progress in Aerospace Science. (DOI: 10.1016/j.paerosci.2018.06.004)
    • Validation: Justifies the use of the parabolic drag polar (\(C_D = C_{D0} + k \cdot C_L^2\)) for regional electric conceptual design, and validates the baseline modeling approaches for propeller efficiency against Mach number.
  • Antcliff, K. R., et al. (2016). Mission Analysis and Aircraft Sizing of a Hybrid-Electric Regional Aircraft. NASA Technical Report 20160007763.
    • Validation: Provides the baseline for simulating a 48-passenger hybrid-electric turboprop with interference and installation penalties. It formally validates the mass-convergence loop methodology and the power split ("Alpha") variations across different mission phases.
  • Marciello, V., et al. (2023). Design Exploration for Sustainable Regional Hybrid-Electric Aircraft: A Study Based on Technology Forecasts. Aerospace (MDPI). (DOI: 10.3390/aerospace10020165)
    • Validation: Targets 50-seat regional aircraft over ~400 nm missions (Clean Sky 2 / GENESIS). This paper cross-checks SPARK’s aerodynamic performance metrics, cruise speeds, and altitudes against modern technology forecasts.

2. Battery Electrochemistry & Sizing (Pillar 2)

Modeling the transient power limits (Voltage Crash) and the cyclic aging (SoH degradation) in core/battery.py requires advanced transient electrochemical scaling.

  • Spinelli, A., et al. (2025). Battery Pack Technological Considerations for Hybrid-Electric Aircraft. The Aeronautical Journal (Cranfield University).
    • Validation: The holy grail for battery.py. This paper validates the Thévenin-style power and voltage-drop modeling. It provides the empirical proof that battery degradation increases inert mass over time, fundamentally justifying SPARK's End of Life (EoL) oversizing parameter (eol_soh_limit = 0.80) to guarantee flight success on the battery's worst day.
  • Antcliff, K. R., et al. (2016). (NASA, cited above)
    • Validation: Validates sizing the battery pack specifically around a strict 80% maximum Depth of Discharge (DoD) for aeronautical safety margins.

3. Aviation Economics & Circular Economy (Pillar 3)

The techno-economic modeling in core/economics.py separates aircraft capital, energy costs, and maintenance, while introducing battery residual value upon aeronautical retirement.

  • Iqbal, H., et al. (2023). A survey of second-life batteries based on techno-economic analysis. Discover Energy. (DOI: 10.1007/s43979-023-00049-5)
    • Validation: Provides quantitative backing for SPARK's circular economy model. It confirms that the aeronautical End of Life is reached at roughly 80% State of Health (SoH) and demonstrates how selling these retired packs for stationary storage absorbs a significant portion of the initial CAPEX.
  • Marciello, V., et al. (2024). Evaluating the economic landscape of hybrid-electric regional aircraft: A cost analysis across three time horizons. Energy Conversion and Management. (DOI: 10.1016/j.enconman.2024.118517)
    • Validation: Introduces the specialized cost framework for hybrid-electric regional aircraft. It justifies the Direct Operating Cost (DOC) decomposition and the inclusion of "technological risk premiums" decaying over short, medium, and long-term horizons.

4. Climate Impact & Non-CO2 Forcing (Pillar 4)

The environmental evaluation modules strictly separate operational emissions from life-cycle manufacturing burdens, and incorporate the massive impact of non-CO2 aviation effects.

  • Thonemann, N., et al. (2024). Prospective life cycle inventory datasets for conventional and hybrid-electric aircraft technologies. Journal of Cleaner Production. (DOI: 10.1016/j.jclepro.2023.140314)
    • Validation: Validates the explicit separation between Scope 1 operational emissions (kerosene burn) and the embodied manufacturing emissions of the battery pack (e.g., estimating ~75-100 kgCO2/kWh for cell manufacturing).
  • Lee, D. S., et al. (2023). Uncertainties in mitigating aviation non-CO2 emissions for climate and air quality using hydrocarbon fuels. Environmental Science: Atmospheres. (DOI: 10.1039/D3EA00091E)
    • Validation: Authored by the world’s leading aviation climatologists, this critical review proves that non-CO2 effects (contrails, NOx, soot) account for roughly two-thirds of aviation's net radiative forcing. This rigorously justifies SPARK's non_co2_multiplier parameter (typically set between 2.0 and 3.0) applied to Jet-A1 fuel burn.