New Engine Thrust Calculation For Arrivals ICRAT 2004 Ivan de Lépinay, ENVISA, Paris (France) based on a dynamic equilibrium equation Welcome!

New Engine Thrust Calculation For Arrivals ICRAT 2004 Introduction based on a dynamic equilibrium equation Scope of the presentation Basics of the environmental impact assessment of aviation Objectives of the SOURDINE II project Reasons for deriving a new thrust equation for arrivals Main principles of the calculation Comparison of results with aircraft manufacturer data Suggestions for further developments

Environmental Impact of Civil Aviation ICRAT 2004 Environmental impact of civil aviation Key facts and figures:  Main types of aircraft pollution: noise and emissions.  1% of the EU population is affected by aircraft noise levels of 65 dB A and more – against 19% for road traffic.  Aircraft CO 2 emissions represent around 4% of the total CO 2 emissions in the EU.  Benefits of the progress in the design of engines are balanced by the traffic increase.  June 2002: Directive 2002/49/EC of the European Parliament on the assessment and management of environmental noise.

The Balanced Approach ICRAT 2004 Environmental impact of civil aviation Reduction of Noise at Source Land-Use Planning and Management Noise Abatement Operational Procedures Operating Restrictions Aircraft Noise Management

Assessing the Noise of Aircraft ICRAT 2004 Aircraft Noise Modelling (Acft Type, Thrust) d Required data (e.g. the Integrated Noise Model) Standard data  Noise-Power-Distance curves  Aircraft data (weight, engine type) Study-specific data  Airport data  Traffic sample  3D trajectories (radar or sim.)  Speed profile (radar or sim.)  Thrust profile (not available from radar or simulated data) (Noise)

Standard Profiles – Altitude (departure) ICRAT 2004 Aircraft Noise Modelling

Standard Profiles – Speed (departure) ICRAT 2004 Aircraft Noise Modelling

Standard Profiles – Thrust (departure) ICRAT 2004 Aircraft Noise Modelling

Noise Contours Maps ICRAT 2004 Aircraft Noise Modelling

Noise Contours Maps ICRAT 2004 Aircraft Noise Modelling

Noise Contours Maps ICRAT 2004 Aircraft Noise Modelling

Standard Profiles – Altitude (departure) ICRAT 2004 Aircraft Noise Modelling

Real Profiles – Altitude (departure) ICRAT 2004 Aircraft Noise Modelling

Standard Profile – Altitude (approach) ICRAT 2004 Aircraft Noise Modelling

Real Profiles – Altitude (approach) ICRAT 2004 Aircraft Noise Modelling

What is ENHANCE? ICRAT 2004 EuropeaN Harmonised Aircraft Noise Contour modelling Environment  Key Tasks:  Pre-process the user data into the noise model format (dbIV for the INM)  Compute the thrust associated with radar/simulated data (corrected net thrust per engine for the INM)  Easily assign pre-defined fixed-points profiles to radar/simulated ground tracks.  Specifically:  INM uses Standard Profiles for each aircraft type  ENHANCE uses a Profile for each flight. (profile = height, speed & thrust vs distance from runway end) Aircraft Noise Modelling

From Radar / Simulation to the INM ICRAT 2004 ENHANCE INM Airport Data Operational Data Radar / Sim Trajectories (X,Y,Z,v) Aircraft dtb (INM 7.0) study cases runways tracks profiles ASCII, MS Access, MS Excel (any column layout) INM dbf input files (one track/profile for each flight) Aircraft Noise Modelling

The SOURDINE II Project ICRAT 2004 The SOURDINE II Project Study of Optimisation procedURes for Decreasing the Impact of NoisE  Funded by the European Commission  Consortium: AENA, AIRBUS France, EEC, INECO, ISDEFE, NLR, SICTA.  Development of new environmental friendly approach and departure procedures + validation in terms of cost, safety, efficiency and operational feasibility.

Engine Noise vs. Airframe Noise ICRAT 2004 The SOURDINE II Project Take-Off Noise Landing Noise

Deriving the New Thrust Equation ICRAT 2004 Deriving the new thrust equation Forces applying on the aircraft: W the weight (=m*g) L the lift D the drag T the total engines’ thrust

Forces Equilibrium ICRAT 2004 Deriving the new thrust equation Dynamic equilibrium: Projected on X and Y axes:

New Thrust Equation ICRAT 2004 Deriving the new thrust equation R f = D / L (drag over lift) is function of:  aircraft configuration  true airspeed  angle of attack

Drag and Lift ICRAT 2004 Deriving the new thrust equation Withρ the air density around the airplane; S the gross wing surface area; C L, C D non-dimensional force coefficients which depend on the aircraft shape, angle of attack, and both the air compressibility and viscosity. Available from BADA

Angle of Attack ICRAT 2004 Deriving the new thrust equation

Results – Comparison with Airbus Data ICRAT 2004 Results - Comparison with Airbus Data Data provided by Airbus (A320 standard approach, time step 1s)  Aircraft altitude  True airspeed  Weight  Angle of attack  Lift  Drag  Total thrust

Altitude Profile ICRAT 2004 Results - Comparison with Airbus Data

Speed Profile ICRAT 2004 Results - Comparison with Airbus Data

Drag over Lift – Calculation Step 10s ICRAT 2004 Results - Comparison with Airbus Data

Thrust – Calculation Step 10s ICRAT 2004 Results - Comparison with Airbus Data

Thrust with Angle of Attack – Step 10s ICRAT 2004 Results - Comparison with Airbus Data

Drag over Lift – Calculation Step 2s ICRAT 2004 Results - Comparison with Airbus Data

Thrust – Calculation Step 2s ICRAT 2004 Results - Comparison with Airbus Data

Thrust with Angle of Attack – Step 2s ICRAT 2004 Results - Comparison with Airbus Data

Small Time Step Limitations ICRAT 2004 Results - Comparison with Airbus Data

Interpretation of Graphs ICRAT 2004 Results - Comparison with Airbus Data  Good correlation during idle thrust phase and final approach.  The angle of attack allows an even better correlation during the final approach segment.  Necessity to use a calculation time step smaller than the typical time of a configuration change for thrust and drag over lift.  Necessity to use a larger calculation time step for the descent angle and acceleration to avoid side effects of altitude and speed measurement inaccuracies.

Further Developments ICRAT 2004 Further Developments Validation with other aircraft types – obtain extra performance data from aircraft manufacturers. Profile smoothing tools to avoid irregularities due to a low measurement accuracy (radar data). Validation of BADA drag and lift coefficients on landing procedures with longer sequences for each intermediate aircraft configuration. Test equation with non ISA atmospheric conditions. Test equation with departure profiles – derated thrust …

New Engine Thrust Calculation For Arrivals ICRAT 2004 Thank you for your attention! based on a dynamic equilibrium equation Thank you for your attention! Ivan de Lépinay ENVISA tel: