Advanced Emission Model (AEM)

 

Definition

The Advanced Emission Model (AEM) is a stand-alone tool, developed and maintained by the EUROCONTROL Experimental Centre in Brétigny, France, which can estimate:

  • the mass of fuel burnt by the main engines of a specified type of aircraft with a specified type of engine flying a specified 4D trajectory;
  • the corresponding masses of certain gaseous and particulate emissions which are produced by the burning of that fuel. The gases whose masses can be estimated include CO2, H2O, the oxides of nitrogen (NOx) and sulphur (SOx), unburnt hydrocarbons (HC), CO, benzene and some other volatile organic compounds (VOCs) and gases (TOGs).

The data input into the AEM is a set of flight profiles containing the types of aircraft and engine as well as 4D trajectory descriptions. This data is processed by the AEM on a flight-by-flight basis. The more precisely the trajectories are defined, depending on the user requirements for the study, the more precisely the resulting data on fuel burnt and emissions generated will be estimated.

Apart from the 4D trajectory descriptions, the AEM requires other input data, such as known (type of aircraft, type of aircraft engine) combinations or emission indices. This data is provided by external suppliers so as to ensure its quality.

 

Typical applications

These include using the model to determine the differences in the masses of fuel burnt and gases and particulate matter (PM) emitted between different en-route scenarios or between the use of different TMA procedures. The maximum number of flights which AEM can handle depends on the hardware resources of the host system (RAM, hard disk space).

 
References for fuel burn and emissions calculation (see thumbnail)

Below 3000 ft

Based on the International Civil Aviation Organization (ICAO) landing and take-off (LTO) cycle

The actual trajectory of an aircraft (which might not be fully described at altitudes below 3000 ft) is not taken into account when the AEM estimates the fuel burnt.

Instead, the calculation is based on the LTO cycle as defined by ICAO.

The ICAO LTO cycle covers four modes of engine operation, namely idle, approach, climb out and take-off, each of which is associated with a specific engine thrust setting and a time in mode. These four modes are used by the AEM to model the following six phases of operation shown in the figure above: taxi-out (idle), take-off (take-off), climb-out (climb-out), approach and landing (approach), and taxi-in (idle).

The ICAO Aircraft Engine Exhaust Databank (AEED) contains rates of fuel flow and emission indices for NOx, HC and CO as a function of the engine thrust setting for a large number of types of aircraft engine.

The AEM associates each type of aircraft which appears in the flight profile data with one of the types of engine listed in the ICAO AEED.

Above 3000 ft

Based on Base of Aircraft Data (BADA)

The calculation of the fuel burnt is based on the data stored in BADA. This database contains data on altitude- and attitude-dependent (i.e. climb, cruise, or descent) performance and rate of fuel burn for more than 150 types of aircraft.

Above 3000 ft, the estimation of the emitted masses of NOx, HC, and CO are based on the ICAO AEED, but the emission indices and rates of fuel flow are modified to take account of the atmospheric conditions found at altitude by using a method, initially developed by the Boeing Company, known as the Boeing (Fuel Flow) Method #2 (BM2).

H2O and CO2 are produced as a direct result of the process of oxidation of the carbon and hydrogen contained in the fuel with the oxygen that is present in the atmosphere. The mass produced of the combined oxides of sulphur depends directly on the sulphur content of the fuel used. The amounts of all three of these types of emissions - H2O, CO2, and SOX - are directly proportional to the amount of fuel burnt.

Benzene emissions, as well as those of VOCs and TOGs and all pollutants derived from VOC-TOG, are proportional to the HC emissions. PM emissions result from the incomplete combustion of fuel.

 

How to access the AEM

If you wish to access the AEM Tool, you will need to obtain an AEM user license.

To do so, please review the user agreement terms and conditions "License Agreement for the EUROCONTROL Advanced Emission Model".

You must include a detailed description of your requirements for the AEM. Your request will not be considered unless an accurate description of your requirements is provided.

Following approval of the request, you will be given access to the AEM support application where you can find the AEM application and documentation. The AEM support application is a principal communication medium between the AEM licensed users and the AEM support team.

ENV Tools team

EUROCONTROL
Address: 
Centre du Bois des Bordes
CS 41005
91222 Brétigny-Sur-Orge Cedex
France