EUROCONTROL method for estimating aviation fuel burnt and emissions --- EMEP/EEA air pollutant emission inventory guidebook 2016

Transcription

1 EUROPEAN ORGANISATION FOR THE SAFETY OF AIR NAVIGATION N/A Specification This documents describes the design of the experiment set up for deriving the accompanying Aircraft type/ Stage length Fuel burn & emissions Excel table EUROCONTROL method for estimating aviation fuel burnt and emissions --- EMEP/EEA air pollutant emission inventory guidebook 2016 DOCUMENT IDENTIFIER : N/A Edition Number : 1.0 Edition Date : 2016/06/29 Status : Released Issue Intended for : General Public Category : EUROCONTROL Specification

2 DOCUMENT CHARACTERISTICS TITLE EUROCONTROL Method for estimating aviation fuel burnt and emissions in the framework of the EMEP/EEA air pollutant emission inventory guidebook 2016 Publications Reference: N/A Document Identifier Edition Number: 1.0 N/A Edition Date: 2016/06/29 Abstract This document describes the method followed for the calculation of the raw data that are used in the 1.A.3.a Aviation annex a.zip accompanying the EMEP/EEA air pollutant emission inventory guidebook These raw data corresponds to the estimation of mass of fuel burnt and the associated masses of emissions that could be produced by a representative set of flights (aircraft types/engines), flying according to their most often used cruise altitude (or cruise flight level) a set of pre-defined distances called reference stage lengths. Contact Person(s) Unit Laurent BOX EUROCONTROL Fuel and Emissions Inventory fuelandemissionsinventory@eurocontrol.int DPS/POL STATUS, AUDIENCE AND ACCESSIBILITY Status Intended for Accessible via Working Draft General Public Intranet Draft EUROCONTROL Extranet Proposed Issue Restricted Internet ( Released Issue Page 2 Released Issue Edition: 1.0

3 DOCUMENT APPROVAL The following table identifies all management authorities who have successively approved the present issue of this document. AUTHORITY NAME AND SIGNATURE DATE Project leader Robin DERANSY 29 June 2016 Edition: 1.0 Released Issue Page 3

4 DOCUMENT CHANGE RECORD The following table records the complete history of the successive editions of the present document. EDITION NUMBER EDITION DATE REASON FOR CHANGE PAGES AFFECTED /06/04 New document All /06/29 Revised and upgraded to Release issue All Page 4 Released Issue Edition: 1.0

5 CONTENTS DOCUMENT CHARACTERISTICS... 2 DOCUMENT APPROVAL... 3 DOCUMENT CHANGE RECORD... 4 CONTENTS... 5 LIST OF FIGURES... 7 LIST OF TABLES Introduction Purpose of the document Abbreviations Definitions Reference material Description of the Method used Determination of the flights data sample Selecting the aircraft types to model Determining the maximum operated/operable stage length Determining cruise flight levels Determination of a trajectory BADA Total Energy Model (TEM) implementation above 6000ft/10000ft Use of ANP data to calculate trajectories below 6000ft/10000ft Optimal cruise management Determination of the mass of fuel burnt and the masses of emissions Model principles Aviation Chapter fuel burn and emissions calculation CCD emissions adjustment Overview of the overall calculation process Reference databases Exercise definition Aircraft models Airports definition Traffic CCD Meteorological conditions Generation of the aircraft trajectories Trajectory validation Emissions calculations Edition: 1.0 Released Issue Page 5

6 ANNEX A Example of input data A.1 Airports A.2 Aircraft types A.3 Flights Page 6 Released Issue Edition: 1.0

7 LIST OF FIGURES Figure 2-A: Method followed to produce the raw data Figure 2-B: Stage length schematic Figure 2-C: Trajectory modelling Figure 2-D: ICAO LTO and CCD cycles Figure 2-E: ICAO LTO and CCD cycles four engine operation modes Figure 2-F: AEM Kernel Fuel and emissions calculation method Figure 2-G: aircraft types versus stage lengths Figure 2-H: Reference stage length versus actual aircraft stage length Figure 2-I: Overall calculation process Edition: 1.0 Released Issue Page 7

8 LIST OF TABLES Table 1: AEM Kernel Fuel and emissions calculation method Page 8 Released Issue Edition: 1.0

9 1. Introduction 1.1 Purpose of the document This document describes the method followed for the calculation of the raw data that are used in the 1.A.3.a Aviation annex a.zip accompanying the EMEP/EEA air pollutant emission inventory guidebook These raw data correspond to the estimation of mass of fuel burnt and the associated masses of emissions that could be produced by a representative set of flights (aircraft types/engines), flying according to their most often used cruise altitude (or cruise flight level) a set of pre-defined distances called reference stage lengths. 1.2 Abbreviations Acronym AEM ANP BADA CAEP CCD ECAC ICAO IFR ISA LTO QNH TMA Definition EUROCONTROL Advanced Emissions Model Aircraft Noise Performance database Base of Aircraft DAta. The EUROCONTROL Aircraft Performance Model Committee on Aviation Environmental Protection Cruise Climb and Descent (flight phases) European Civil Aviation Conference International Civil Aviation Organisation Instrument Flight Rules International Standard Atmosphere ISO 2533:1975/Add 2: Landing and Take Off (flight phases) Regional or airfield pressure setting Terminal Manoeuvring Area 1.3 Definitions Acronym EUROCONTROL Definition EUROCONTROL, the European Organisation for the Safety of Air Navigation, is an intergovernmental organisation with 41 Member States, committed to building, together with its partners, a Single European Sky that will deliver the air traffic management performance required for the twenty-first century and beyond. Edition: 1.0 Released Issue Page 9

10 Acronym IMPACT PRISME Definition EUROCONTROL online tool dedicated to multi-airport environmental impact assessments for noise, gaseous and particulate emissions, and local air quality. Worldwide fleet database used to provide ATM enriched airframe specific data for use by external stakeholders and EUROCONTROL business units Reference material [1] ICAO - Annex 16 to the Convention on International Civil Aviation Environmental Protection Volume II Aircraft Engine Emissions [2] ICAO Doc 9889 Airport Air Quality [3] ICAO Doc 9646 Engine Exhaust Emissions Data Bank [4] ICAO Doc 8643 Aircraft Type Designators [5] ICAO Doc 9911 Recommended Method for Computing Noise Contours around Airports [6] ECAC Doc 29 3rd edition Volume 1 & 2 - Report on Standard Method of Computing Noise Contours Around Civil Airports Page 10 Released Issue Edition: 1.0

11 2. Description of the Method used The method followed to produce the raw data used in the 1.A.3.a Aviation annex a.zip accompanying the EMEP/EEA air pollutant emission inventory guidebook 2016 is described in Figure 2-A and consist of the following steps: 1. Determination of the flights data sample: This includes the identification of the aircraft types to be modelled, and for each of them to determine its associated engine(s) and the maximum stage length that this aircraft type usually fly. 2. Determination of a trajectory for each aircraft type selected in Step 1 and for each stage length this aircraft type can fly by applying an aircraft performance model. 3. Determination of the mass of fuel burnt and the masses of emissions of each aircraft type, and for the different engines with which they can be equipped, for each stage length, and from gate to gate. Data sample Aircraft type Flights Stage length Cruise flight level Performance model Flights trajectories Emissions model Flights Fuel burn and emissions Figure 2-A: Method followed to produce the raw data This method relies on the use of two main EUROCONTROL environmental impact assessment tools: 1. The IMPACT modelling platform, and 2. The Advanced Emission Modelling (AEM) model. These tools have been recognised by the ICAO CAEP Working groups. They are compliant with the recommended practises as published by ICAO (see References [1] and [2]) and they provide the solutions to the objectives of the experiments. Edition: 1.0 Released Issue Page 11

12 2.1 Determination of the flights data sample The determination of the flight data sample is done by: 1. Selecting a set of aircraft types to model; 2. Determining the maximum stage lengths for a specific aircraft type; 3. Determining the cruise flight level for a specific aircraft type / stage length Selecting the aircraft types to model The EUROCONTROL PRISME database stores information about air traffic movements in the ECAC area flying IFR. It has been decided to select, from the PRISME database, the aircraft types that represent 99% of the flight movements in the ECAC area in It has to be noted that, in PRISME, each aircraft type selected represents in fact a certain range of variants using different engine types with similar performances. For example: The aircraft type ATR42 is used for ATR42-310, ATR42-500, ATR42-600, etc. Furthermore, each selected aircraft type can be categorised by an ICAO aircraft type designator as defined in the reference document ICAO Aircraft Type Designators [4]. For example: The ICAO code SBR1 represents the aircraft types SAB60 (Sabreliner 60), SAB65 (Sabreliner 65), among others. The aircraft type is used to find fuel burn/emissions data and performance data in reference databases. When this aircraft type is not referenced, a proxy can be identified to enable the modelling of the aircraft trajectory and the estimation of the fuel burnt and the emissions. For example: the aircraft type A306 can be modelled by an A R in ANP V2.0, an A300B4-622 in BADA4.1, and an A306 in AEM Determining the maximum operated/operable stage length In the EMEP/EEA air pollutant emission inventory guidebook 2016, the stage length has been defined as the great circle distance to be flown between the end of the ICAO LTO departure phase and the beginning of the ICAO LTO arrival phase, which corresponds to the trajectory flown with an altitude QNH greater or equal to 3000ft in ISA conditions (see Figure 2-B). Altitude Climb/Cruise/Descent (CCD) Aircraft altitude >= 3000ft 3000 ft Departure Airport STAGE LENGTH Landing and Take Off (LTO) Aircraft altitude < 3000ft Destination Airport Figure 2-B: Stage length schematic Page 12 Released Issue Edition: 1.0

13 The reference stage lengths chosen for the EMEP/EEA air pollutant emission inventory guidebook 2016 are: 125Nm, 200Nm, 250Nm, 500Nm, 750Nm, 1000Nm, 1500Nm, 2000Nm, 2500Nm, 3000Nm, 3500Nm, 4000Nm, 4500Nm, 5000Nm, 5500Nm, 6000Nm, 6500Nm, 7000Nm, 7500Nm, and 8000Nm. For economic reasons or due to their performance envelope, some of the aircraft types selected are not operated or cannot be operated on some of the reference stage lengths listed above. The maximum reference stage operated by a specific aircraft type was determined by querying the EUROCONTROL PRISME database or by using the declared maximum operation range as provided by the manufacturer Determining cruise flight levels For each selected aircraft type the average cruise flight level corresponding to each reference stage length to be modelled was determined by querying the PRISME database or by using the optimum flight level as provided by the aircraft manufacturers. 2.2 Determination of a trajectory The trajectory calculator implements a point mass model, relying on both the ANP and the BADA performance data. The calculation method (Figure 2-C) is further described below. Cruise speed Optimal cruise level management BADA 3 & BADA 4 Performances Altitude Climb at constant Mach/CAS 3 Descent at constant Mach/CAS 3000 ft Departure profile < ft Arrival profile < 6000 ft ANP Performances LTO Phases < 3000 ft LTO Phases < 3000 ft Figure 2-C: Trajectory modelling BADA Total Energy Model (TEM) implementation above 6000ft/10000ft BADA is an Aircraft Performance Model developed and maintained by EUROCONTROL, in cooperation with aircraft manufacturers and operating airlines. BADA is based on a kinetic approach to aircraft performance modelling, which enables aircraft trajectories and the associated fuel consumption to be accurately predicted. BADA includes both model specifications that provide the theoretical fundamentals to calculate aircraft performance parameters and the datasets containing aircraft-specific coefficients required to calculate their trajectories. Edition: 1.0 Released Issue Page 13

14 The BADA 3 family is today s industry standard for aircraft performance modelling in the nominal part of the flight envelope, and provides close to 100% coverage of aircraft types operating in the ECAC region. The latest BADA 4 family provides increased levels of precision in aircraft performance parameters over the entire flight envelope, and covers 70% of aircraft types operating in the ECAC region. In the CCD portion (more precisely from 10,000ft in the climb phase, and down to 6,000ft in the descent phase), the trajectory calculator of IMPACT uses the BADA 4 data, in conjunction with a full implementation of the BADA Total Energy Model (TEM). When BADA 4 performance data do not exist yet for a given aircraft type, its BADA 3 performance data is used Use of ANP data to calculate trajectories below 6000ft/10000ft The IMPACT trajectory calculator uses the aircraft performance coefficients of the ANP database - in conjunction with the aircraft performance calculation method provided in ECAC Doc. 29 [6] and ICAO Doc 9911 [5] - to model aircraft trajectories within the TMA portion (more precisely below 10,000ft for departure and below 6000ft for arrivals). The reasons for adopting this approach are twofold: The use of ANP data in conjunction with the aircraft performance calculation method described in the above-mentioned guidance documents constitutes the current best modelling practice for airport noise assessments and is often part of legal requirements (ex: the END 2002/49 of the EC) BADA, even in its latest version (BADA 4 family) provides engine coefficients for the MaxTakeoff ratings (used during the initial climb segments) only for a very limited number of aircraft types (unlike ANP). The aircraft mass at the take-off is determined by the selected ANP aircraft model Optimal cruise management The IMPACT trajectories tries to find the trajectory that will allow each aircraft to reach the optimal cruise flight level entered as an input. Depending on the aircraft type and the stage length, the pre-determined optimal cruise level might be too high to be reached directly at the end of the climb phase. In that case, a new intermediate and reachable optimal cruise level is calculated. The aircraft continues its cruise at this flight level until its weight enables it to reach the next best suitable flight level, with a maximum offset of 2000 ft. This process is repeated until the maximum optimum cruise level is reached. The aim of this implementation is to model, as closely as possible, the real life operational management of aircraft in economic mode, when pilots require successive flight levels to Air Traffic Controllers. Page 14 Released Issue Edition: 1.0

15 2.3 Determination of the mass of fuel burnt and the masses of emissions Model principles The Advanced Emission Model (AEM) is used to calculate the emissions (CO 2, water vapour [H 2 O], SO X, NO X, hydrocarbons [HC], CO, volatile organic compounds [VOCs], total organic gases [TOGs]) and fuel burn of aircraft based on precise flight profile information which is combined with more detailed information about aircraft fuel flow and specific engine emissions both for the LTO and CCD flight phases. The emissions for the H 2 O and CO 2 pollutants are a direct result of the oxidation process of the carbon and hydrogen contained in the fuel with the oxygen contained in the atmosphere. The SOx emissions depend directly on the sulphur content of the fuel used. All three are directly proportional to the mass of fuel burnt Benzene emissions, as well as other VOC, TOG and all pollutants derived from VOC-TOG, are proportional to the HC emissions. The emissions of particulate matter (PM) are calculated by using the First Order Approximation method as described by the ICAO Doc 9889 [2]. AEM links each aircraft appearing in the input traffic sample to one of the engines in the ICAO Engine Exhaust Emissions Data Bank or another emission database. Figure 2-D: ICAO LTO and CCD cycles Edition: 1.0 Released Issue Page 15

16 Below 3000 ft: LTO flight phases Below 3000 ft, the fuel burn calculation is based on the LTO cycle defined by the ICAO Engine Certification specifications. The ICAO LTO cycle covers four engine operation modes, (see Figure 2-E) which are used in AEM to model the six following phases of operation: (1) Taxi-Out, (2) Take- Off, (3) Climb-Out, (7) Approach, (8) Landing (Approach), and (9) Taxi-In. Phase(s) Engine mode Thrust setting 1 Idle 7% 2 Take off 100% 3 Climb out 85% 7 and 8 Approach 30% 9 Idle 7% Figure 2-E: ICAO LTO and CCD cycles four engine operation modes The rate that fuel is burnt at each defined thrust level (7%, 30%, 85%, and 100%) derived from the data stored in a number of aircraft engine emissions database, one such database is the ICAO Engine Exhaust Emissions Data Bank [3], which includes fuel burn rate and CO, HC and NOx associated emission indices [g/kg of fuel burnt] for a very large number of aircraft. Other emissions associated with the amount of fuel burnt are CO 2, H 2 O, SOx and PM. For the VOCs and TOGs, the emission indices are given in terms of the amount of HC emitted. Once the amount of fuel burnt in a LTO phase is known, the associated emissions can be calculated by multiplying the amount of fuel burnt (for CO,HC, NOx, CO 2, H 2 O and SOx) or of HC (for the VOCs and TOGs) in that LTO phase by the relevant emission index. Above 3000 ft: CCD flight phases Above 3000 ft, the fuel burn calculation is based on the BADA performance values. This database provides altitude- and attitude-dependent performance and fuel burn data for more than 150 aircraft types. Most of the emission calculations are based on the ICAO Engine Exhaust Emissions Data Bank indices, but emission factors and fuel flow are adapted to the atmospheric conditions at altitude by using a method initially developed by The Boeing Company (The Boeing Fuel Flow Method 2 BFFM2) and modified by the EUROCONTROL Experimental Centre (EEC-BFFM2). EEC-BFFM2 makes it possible to estimate emissions for the NOx, HC, and CO pollutants. Page 16 Released Issue Edition: 1.0

17 Figure 2-F: AEM Kernel Fuel and emissions calculation method Table 1: AEM Kernel Fuel and emissions calculation method Aviation Chapter fuel burn and emissions calculation In order to generate the raw data used by 1.A.3.a Aviation annex a.zip accompanying the EMEP/EEA air pollutant emission inventory guidebook 2016, the trajectories generated with Edition: 1.0 Released Issue Page 17

18 IMPACT are processed with AEM kernel, which calculates the fuel burnt and emissions. Below 3000 feet, the fuel burnt is provided by the ICAO Engine exhaust database fuel flow, based on the ICAO LTO times in phase: 1140 seconds for Taxi out:, 42 seconds for Take-off, 132 seconds for Climb out, 200 seconds for Approach, 40 seconds for Landing, and 420 seconds for Taxi in CCD emissions adjustment The modelling of the performance of different aircraft types between the same two airports induces minor differences of stage lengths. The consequence is that the distance of flight which concerns the CCD portion of the flight differs from one aircraft type to another (see Figure 2-G), and de facto the basis for the fuel burn and emission calculation. AC 1 AC 2 Altitude AC ft Departure Airport Stage length AC3 Stage length AC2 Destination Airport Stage length AC1 Reference Stage Length Figure 2-G: aircraft types versus stage lengths This difference is greater for short stage lengths than for longer ones (see Figure 2-H), on average of the aircraft types, because of the range of very different performances of short-range flights (from single piston engines to heavy jets). It can be noticed that this relative difference is less than 8.6% in the worst case (125Nm for BE60). For stage lengths above 500 Nm, it is reduced below 2.5%. It is then assumed that the CCD fuel burnt and emissions can be calculated by extrapolating the fuel burn and emissions values for each aircraft real stage length to the reference stage length. As an example, we have then, for a given reference stage length (Ref. Stage Length) and aircraft type: Fuel burnt (Ref. Stage length) = Fuel burnt (CCD distance) * Ref. Stage length / CCD distance It is the same for the calculated emissions. Page 18 Released Issue Edition: 1.0

19 Figure 2-H: Reference stage length versus actual aircraft stage length Edition: 1.0 Released Issue Page 19

20 2.4 Overview of the overall calculation process As shown in Figure 2-I, the overall calculation process consists of: setting up the IMPACT platform: o Reference databases o Aircraft models identification (mapping) o Exercise definition Flights Airspace Meteorological context generating the data sample trajectories with IMPACT validating these trajectories (validation lookup) calculating the data sample fuel burnt and emissions with AEM IMPACT Airports Traffic Aircraft models Exercise definition IMPACT core BADA 3.12 BADA 4.2 ANP V2 No Generation of the aircraft trajectories Trajectories validation Is Validated? AEM Yes Emissions calculations ICAO EEDB Figure 2-I: Overall calculation process Page 20 Released Issue Edition: 1.0

21 2.5 Reference databases The references databases are: ID Version BADA BADA ANP V2.0 AEM (This version includes the ICAO EEDB 02/2016) 2.6 Exercise definition Aircraft models The aircraft models are defined with the following characteristics: ID Aircraft Type ANP type BADA BADA Version type AEM type Description / notes A unique aircraft ID name. This ID is either provided by the PRISME database or the ICAO aircraft designator database. The identified ANP aircraft type which provides the performance model below 10000ft for the departure phases and below 6000ft for the arrival phases. The identified BADA aircraft type which provides the performance model above 10000ft for the departure phases and above 6000ft for the arrival phases. The type of BADA performance database which is used to model this aircraft. The type of AEM model aircraft. This identifier links the Aircraft Type to a BADA3 fuel flow model, an engine type (ICAO EDDB) and a number of engines Airports definition The airports are defined using the following characteristics: ID Name Latitude 0 Longitude Elevation Meteorological conditions at the runway Description / notes The airport identifier The longitude of the aircraft is defined as: Great circle distance (0,0)(0,latitude) = Reference stage length + 17 Nm. 0 ft ISA conditions, relative humidity of 70% and runway headwind of 8kt Edition: 1.0 Released Issue Page 21

22 2.6.3 Traffic The traffic definition consists in the definition of the flights which are assessed: ID Flight name Aircraft type ADEP ADES Cruise flight level Departure time Description / notes The flight identifier The aircraft type The departure airport. All the flights have the same departure airport. The arrival airport. The maximum cruise flight level to reach. The departure time is the same for all the flights CCD Meteorological conditions The CCD meteorological conditions are ISA conditions. 2.7 Generation of the aircraft trajectories This phase of the process consists of the generation by the IMPACT core application of the 4D trajectories of the flights with the following options: Use of the input times; Step cruise mode is selected. 2.8 Trajectory validation Once the trajectories are generated, a set of analysis indicators determine if the fuel burn and emissions can be calculated from them, in order to identify any data sample issues: Reached cruise flight level; CCD distance Vs Reference stage length. 2.9 Emissions calculations Only the CCD trajectories are provided to AEM for the emissions calculations. AEM performs the LTO emissions and adds them to the flight results. The fuel flow calculations are performed by the AEM emissions model with the following setup: Generation of the LTO flight phases ICAO fuel flow determination in LTO phase (<3000ft) AEM/BADA 3.12 fuel flow determination (>=3000ft) ISA atmospheric conditions Calculation of the emissions by segment, by flight and by phase. Page 22 Released Issue Edition: 1.0

23 ANNEX A Example of input data A.1 Airports AIRPORTS APT_ID REF_POINT_LAT ELEVATION_FT TEMPERATURE_FAHR PRESSURE_INHG RH% HEADWIND_KT REF_POINT_LONG A.2 Aircraft types Example: A320 AIRCRAFT TYPE DETAIL NAME AEM ANP BADA4 TYPE ENG MANUFACTURER NB ENG TYPE ACFT WTC A320-A A A320-A A A Jet AIRBUS INDUSTRIE 2 Landplane M A.3 Flights Example: A320 stage length 125 Nm FLIGHT_ID ACFT_ID CRUISE_ALT APT_DEP APT_DES DATE_DEP TIME_DEP A320_125+A320-A A320-A /01/ :00:00 Edition: 1.0 Released Issue Page 23

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