Florian Wolters

Potential Impact of Renewable Fuels and Technological Innovations on Global Air Traffic Emissions Development by 2050

The aviation industry has set ambitious reduction targets for future air traffic emissions to compensate for the environmental impact of increasing air transport. Besides technological innovation in the fields of aircraft and engine technology, alternative fuels from non-petroleum feedstock are often seen as having long-term potential to offer reductions in aviation’s greenhouse gas emissions. The current paper studies the effects of potential emission reduction measures up to the year 2050, taking technology developments as well as renewable fuel scenarios into account. The individual impacts of both contributions are assessed in terms of fuel burn, direct CO2 emissions, and life cycle CO2eq emissions. The results are compared to the agreed mid and long term reductions targets, i.e. carbon-neutral growth by 2020 and halving CO2 emissions by 2050.Future air traffic emissions are evaluated based on one reference scenario and three technology scenarios, derived from the ICAO global fuel burn forecast and Flightpath 2050 technology improvement goals. Four renewable fuel penetration scenarios are considered and the impact of alternative renewable fuels in terms of Synthetic Paraffinic Kerosene (SPK) on fuel burn and direct CO2 emissions are taken into consideration. Moreover, to account for the fuels’ life cycle emissions three different life cycle CO2eq emission reduction potentials scenarios are applied.This study provides a quantitative view on exponential growth of aviation fleet CO2 emissions. The potential of individual contributions are explicitly highlighted and potential developments in air traffic emissions are quantified. The results show that in addition to significant efficiency improvements in aircraft and engine technology, a high renewable fuel share will be required to compensate for steady air traffic growth and to achieve carbon neutral growth from 2020 onwards and a 50% CO2eq emission reduction by 2050.Copyright

Simulation process for perception-based noise optimization of conventional and novel aircraft concepts

Noise from civil air traffic affects millions of people worldwide. Aircraft noise management should be addressed by different principal elements, such as noise reduction at the source and noise abatement operational procedures. To date, usually conventional noise metrics are applied towards the acoustical optimization while noise effects are usually only indirectly accounted for. The objective of this contribution is the optimization of conventional and novel aircraft concepts with respect to their evoked aircraft noise annoyance. The optimization will be based on the perceived sound and the associated annoyance. To do so, virtual aircraft flyovers are auralized based on noise level predictions, i.e. they are artificially made audible. The auralization is accomplished by parametric sound synthe- sis and a 3D spatial audio technique. Short-term noise annoyance is measured through controlled listening experiments in which participants rate the level of annoyance for each auralized flyover. The aircraft design and the flight path are evaluated according to the associated annoyance. The subsequent ranking can be compared to a conventional ranking based on standard noise metrics. The results of such a study will help to identify parameters describing aircraft and flight path parameters that have an impact on noise annoyance. Consequently, these parameters can then be selected for further optimization to reach even lower levels of noise annoyance and not simply reduce standard noise metrics. Ultimately, the main goal of the research is optimizing the noise annoyance of (novel) aircraft along tailored flight paths. This contribution documents the status quo of the joint DLR and Empa activities, i.e., the structure of a pilot study. First results that were obtained while developing the methodology and the test cases within the pilot study are presented.

COMPARISON OF A HEAT SOAKAGE MODEL WITH TURBOFAN TRANSIENT ENGINE DATA

In the present paper, a transient performance code is employed to predict on-wing test data of the IAE-V2500 engine mounted on an Airbus A320-232. The test data was recorded by the engine control system and may serve as an open basis for validation of future transient studies. For the current investigation, the employed code considers the fundamental equations of the constant mass flow method as well as heat transfer effects by a lumped parameter approach. The study focuses on seven accelerations and one deceleration. Engine test data was gathered with 10Hz sampling rate, imprinting the applied time step of the model. First, the steady-state matching of the test data was conducted. Subsequently, the measurement quantities fuel flow, inlet temperature and inlet pressure were prescribed as time-varying boundary conditions to the transient model. The results of the standard transient model and the model including thermal effects were compared with temperatures, pressures and shaft speeds. The LPT outlet temperature and the working line excursion in the booster map were examined in detail. The outcome concurs with the original statement that thermal effects are mandatory to enhance model accuracy. Lastly, a sensitivity analysis of the thermal input parameters was accomplished and its influence on model prediction investigated.