Erweiterung eines Trajektorienrechners zur Nutzung meteorologischer Daten für die Optimierung von Flugzeugtrajektorien

Das Fliegen wird maßgeblich durch die Wind- und Wettersituation entlang des Flugweges beeinflusst. Vor diesem Hintergrund wurde das Trajectory Calculation Module (TCM) – ein bestehendes Werkzeug zur Simulation von Flugtrajektorien – dahingehend erweitert, dass im Zuge der Trajektoriensimulation anstelle von Standardatmosphären-Bedingungen auch reale atmosphärische Bedingungen miteinbezogen werden können. Hierfür wurden insbesondere eine Flughöhen- sowie eine Fluggeschwindigkeitsregelung integriert, die die Einhaltung typischer Flugphasenrandbedingungen auch unter von der Standardatmosphäre abweichenden meteorologischen Bedingungen gewährleisten. Die Wirkung horizontaler Winde wurde zudem durch deren Superposition mit der Fluggeschwindigkeit gegenüber der Luft erfasst. Ferner wurde für die laterale Optimierung von Flugrouten unter Windeinfluss ein Algorithmus auf Basis von Prinzipien der Optimalsteuerungstheorie entwickelt. Das zu minimierende Kostenfunktional wurde so gewählt, dass sowohl die Flugzeit als auch der Einfluss einer ortsabhängigen Straffunktion Berücksichtigung finden können. Als Anwendungsfall wurden Klimakostenfunktionen, die die Sensitivität der Klimawirkung gegenüber der Emission von Schadstoffen als Funktion des Ortes beschreiben, als Straffunktion in das Kostenfunktional der Optimierung integriert. Auf dieser Grundlage wurde anhand einer exemplarischen Flugroute untersucht, inwieweit sich die durch den Flug verursachte Klimawirkung vermindern ließe, wenn eine erhöhte Flugzeit in Kauf genommen würde

Note on the Non-CO2 Mitigation Potential of Hybrid-Electric Aircraft Using "Eco-Switch"

Non-CO2 effects, like ozone production and contrail cirrus formation, account for about 50-75% of aviation's climate impact, which can be effectively mitigated by re-routing flights around highly climate-sensitive areas, like ice-supersaturated regions (ISSRs). With electric drives forming no contrails and binding all life-cycle emissions to the ground, also hybrid-electric aircraft (HEA) offer the capability to mitigate non-CO2 effects by switching to full-electric mode while passing those areas. For investigating the eco-switch HEA mitigation potential, a cost-benefit assessment of eco-switch trajectories is performed for two weather situations and benchmarked against the mitigation potential of climate-optimized re-routings. We studied the impact of the HEA fuel flow and the cruising time in a full-electric operation and identified distinct weather-related differences. If the eco-switch concept is applied while passing ISSRs, we found a significant mitigation potential for all combinations of full-electric cruise times and HEA fuel flow levels. This strongly implies that the climate impact of flights dominated by contrail-cirrus is largely driven by the level of climate sensitivities along the trajectory, rather than by emission levels (aircraft design). If no ISSR is crossed, the climate impact is increasing with increasing HEA fuel flow, implying that the emission volume outweighs the local climate sensitivity

FlyATM4E (SESAR ER) - Mitigating aviation climate impact by climate-optimized aircraft trajectories

Darstellung des Projekts FlyATM4

A concept for multi-criteria environmental assessment of aircraft trajectories

Comprehensive assessment of the environmental aspects of flight movements is of increasing interest to the aviation sector as a potential input for developing sustainable aviation strategies that consider climate impact, air quality and noise issues simultaneously. However, comprehensive assessments of all three environmental aspects do not yet exist and are in particular not yet operational practice in flight planning. The purpose of this study is to present a methodology which allows to establish a multi-criteria environmental impact assessment directly in the flight planning process. The method expands a concept developed for climate optimisation of aircraft trajectories, by representing additionally air quality and noise impacts as additional criteria or dimensions, together with climate impact of aircraft trajectory. We present the mathematical framework for environmental assessment and optimisation of aircraft trajectories. In that context we present ideas on future implementation of such advanced meteorological services into air traffic management and trajectory planning by relying on environmental change functions (ECFs). These ECFs represent environmental impact due to changes in air quality, noise and climate impact. In a case study for Europe prototype ECFs are implemented and a performance assessment of aircraft trajectories is performed for a one-day traffic sample. For a single flight fuel-optimal versus climate-optimized trajectory solution is evaluated using prototypic ECFs and identifying mitigation potential. The ultimate goal of such a concept is to make available a comprehensive assessment framework for environmental performance of aircraft operations, by providing key performance indicators on climate impact, air quality and noise, as well as a tool for environmental optimisation of aircraft trajectories. This framework would allow studying and characterising changes in traffic flows due to environmental optimisation, as well as studying trade-offs between distinct strategic measure

Robust 4D Climate Optimal Flight Planning in Structured Airspace using Parallelized Simulation on GPUs: ROOST V1.0

The climate impact of the non-CO2 emissions, being responsible for two-thirds of aviation radiative forcing, highly depends on the atmospheric chemistry and weather conditions. Hence, by planning aircraft trajectories to reroute areas where the non-CO2 climate impacts are strongly enhanced, called climate-sensitive regions, there is a potential to reduce aviation induced non-CO2 climate effects. Weather forecast is inevitably uncertain, which can lead to unreliable determination of climate-sensitive regions and aircraft dynamical behavior and, consequently, inefficient trajectories. In this study, we propose robust climate optimal aircraft trajectory planning within the currently structured airspace considering uncertainties in the standard weather forecasts. The ensemble prediction system is employed to characterize uncertainty in the weather forecast, and climate-sensitive regions are quantified using the prototype algorithmic climate change functions. As the optimization problem is constrained by the structure of airspace, it is associated with hybrid decision spaces. To account for discrete and continuous decision variables in an integrated and more efficient manner, the optimization is conducted on the space of probability distributions defined over flight plans instead of directly searching for the optimal profile. A heuristic algorithm based on the augmented random search is employed and implemented on graphics processing units to solve the proposed stochastic opti- mization computationally fast. The effectiveness of our proposed strategy to plan robust climate optimal trajectories within the structured airspace is analyzed through two scenarios: a scenario with large contrails&rsquo; climate impact and a scenario with no formation of persistent contrails. It is shown that, for a night-time flight from Frankfurt to Kyiv, a 55 % reduction in climate impact can be achieved at the expense of a 4 % increase in cost.</p

GLOWOPT - A new approach towards global-warming-optimized aircraft design

A new concept for designing aircraft with minimum climate impact is presented. The paper describes the GLOWOPT approach, which is currently being implemented in the framework of the Clean Sky 2 programme. It aims at developing and validating so-called Climate Functions for Aircraft Design (CFAD). Those functions constitute an easy-to-use tool, which can be integrated into existing aircraft synthesis workflows without high adaptation effort. They will be made available to the relevant stakeholders including aircraft manufacturers, and thus allow for the development of new aircraft with a significantly reduced impact on global warming

Climate-optimized trajectories and robust mitigation potential: flying ATM4E

Aviation can reduce its climate impact by controlling its CO2-emission and non-CO2 effects, e.g., aviation-induced contrail-cirrus and ozone caused by nitrogen oxide emissions. One option is the implementation of operational measures that aim to avoid those atmospheric regions that are in particular sensitive to non-CO2 aviation effects, e.g., where persistent contrails form. The quantitative estimates of mitigation potentials of such climate-optimized aircraft trajectories are required, when working towards sustainable aviation. The results are presented from a comprehensive modelling approach when aiming to identify such climate-optimized aircraft trajectories. The overall concept relies on a multi-dimensional environmental change function concept, which is capable of providing climate impact information to air traffic management (ATM). Estimates on overall climate impact reduction from a one-day case study are presented that rely on the best estimate for climate impact information. Specific weather situation that day, containing regions with high contrail impact, results in a potential reduction of total climate impact, by more than 40%, when considering CO2 and non-CO2 effects, associated with an increase of fuel by about 0.5%. The climate impact reduction per individual alternative trajectory shows a strong variation and, hence, also the mitigation potential for an analyzed city pair, depending on atmospheric characteristics along the flight corridor as well as flight altitude. The robustness of proposed climate-optimized trajectories is assessed by using a range of different climate metrics. A more sustainable ATM needs to integrate comprehensive environmental impacts and associated forecast uncertainties into route optimization in order to identify robust eco-efficient trajectories

MITIGATION OF AVIATIONS CLIMATE IMPACT THROUGH ROBUST CLIMATE OPTIMIZED TRAJECTORIES IN INTRA-EUROPEAN AIRSPACE

Global aviation actively contributes to anthropogenic global warming. Climate impact mitigation potential has been previously studied and quantitative estimates were determined. However, these estimates are associated with uncertainties in climate impact modelling and weather forecast. In this study, a methodology to consider these uncertainties when optimising trajectories in European airspace is presented