300 — Mechanisms of the environmental impact of aviation¶
This chapter deals with the mechanisms of formation of combustion products and their role within atmospheric processes, hence it sits between engine physics and climate-relevant quantities.
More specifically, emphasis is given to:
1) Combustion chemistry / emissions models
Example: given a fuel/air mixture and residence time, what emission indices do we get? (chemical kinetics + reactors)
2) Atmospheric formation criteria models
Example: when do contrails form? (water emissions + thermodynamics + saturation curves)
The exercises below expose both, using a minimal but mechanistic workflow.
Exercises in this chapter¶
300.1 — Contrail formation models (Schmidt–Appleman)¶
A guided notebook implementing the Schmidt–Appleman criterion and building a contrail diagram, using saturation curves and mixing lines.
300.2 — Emission indices from a homogeneous reactor (Cantera)¶
A Python script using Cantera to simulate a constant-pressure homogeneous reactor with a kerosene surrogate mechanism (incl. NOx) and compute time-dependent emission indices (EI).
Learning outcomes¶
After completing this chapter, you should be able to:
- Explain what the Schmidt–Appleman criterion is and what assumptions it makes
- Use saturation curves (water/ice) and an isobaric mixing line to determine contrail formation thresholds
- Define and compute emission indices (EI) on a mass basis (kg species / kg fuel)
- Understand what a homogeneous reactor model captures—and what it misses—about real combustors
- Interpret trade-offs between CO/NO formation, equivalence ratio, and temperature histories
These skills support later chapters where non-CO₂ effects and engine–mission coupling matter.