AIM's architecture contains a set of integrated modules of the key elements relevant to the project goal. These modules were developed during the initial phase of the AIM project and form the initial basis for the ACCLAIM project which is now underway.
- Aircraft Technology & Cost Module simulates aircraft fuel use, emissions production and ownership/operating costs for various airframe/engine technology evolution scenarios.
- Air Transport Demand Module predicts passenger and freight flows into the future between origin-destination city pairs within the global air transportation network.
- Airline & Airport Activity Module investigates operations within the vicinity of the airport and calculates delays and future airline response to them (e.g. via re-routing, re-scheduling, etc).
- Aircraft Movement Module simulates airborne trajectories between city-pairs, accounting for inefficiencies and delays for given air traffic control scenarios.
- Global Climate Module investigates global environmental impacts of the aircraft movements in terms of multiple emissions species and contrails.
- Air Quality & Noise Module investigates local environmental impacts from dispersion of critical air quality species and noise from take-off and landing operations.
These modules were developed during the initial phase of AIM and are currently being updated for use with the ACCLAIM project. Further information on the structure and methodology of the updated modules will be made available as the project progresses. ACCLAIM is an open-source project so we also anticipate making the model source code available.
Strengths of AIM's Architecture
The modular architecture being pursued for AIM has many significant strengths:
Each module provides an input site for candidate “policy levers” that manipulate the evolution of the air transportation system and hence allows an assessment of their environmental and economic impacts. Other types of policy options affect multiple modules simultaneously, such as emissions trading impacts on taxation/charges, technology and operations.
Key interdependencies are captured, allowing data transfer and feedback between the modules. This allows complex trade-offs between competing environmental (e.g. noise vs. CO2 vs. NOx) and economic metrics to be examined using AIM.
The temporal and spatial resolution of each module can be tailored to the application being considered. For example, in order to run the full integrated model within a reasonable time, annual/regional aggregate input data and first-order module definitions might be appropriate. More detailed regional assessments over shorter timeframes can be accommodated with appropriate input data and higher-order module definitions. Only a subset of modules need be run if the complete set is not required for the application being considered.
Module definitions from other developers can be substituted to examine their interactions within the wider integrated structure (subject to appropriate interfaces existing).
Future Growth Potential
The modular architecture allows natural growth and extension of capabilities. Subsequent phases of AIM development will focus on expanding its capabilities in line with needs, for example to include modelling of multi-modal passenger decision options or to capture emerging trends in air transportation system evolution (e.g. future regional demand or very light jet/air taxi growth).