Model development for climate optimized aircraft design

Aviation as an important transport sector contributes to anthropogenic climate change via CO₂ effects and non-CO₂ effects. Non-CO₂ effects include e.g., effects from NO_x emissions, H₂O emissions and the formation of contrails. Mitigation options include optimization of aircraft operations, e.g., re-routing, and optimization of the aircraft design, while this work focuses on the second option via providing a model for aircraft design optimization. Furthermore, we take CO₂ and non-CO₂ effects into account.
Previous research (e.g. Grewe et al., 2014) investigated the optimization of aircraft operations with the use of climate cost functions. With these functions, the climate impact per unit non-CO₂ emission/flown distance is described depending on the type of emission, the emission location and corresponding time. An equivalent model for aircraft design purposes is currently missing. It has to cover a suitable route network with emission locations and altitudes to be able to optimize regarding the climate impact of CO₂ and non-CO₂ effects. Within the EU Clean Sky 2 project GLOWOPT, this concept is applied for aircraft design features, presented as climate functions for aircraft design (CFAD).
Here, we present the development routine for the CFAD. As input, emission inventories based on a long-range aircraft (A350 as baseline in this study) are used. The emission inventories cover a set of climb angles and final cruise altitudes to combine both the aircraft design parameter and geographical information of emissions. The climate impact is calculated with the climate-chemistry response model AirClim (Grewe and Stenke, 2008; Dahlmann et al., 2016) to create a response surface. The climate metric Average Temperature Response with a time horizon of 100 years is used as a measure for the climate impact. The created response surface, the CFAD, can be integrated in the aircraft design process to optimize the aircraft design. The CFAD are to be verified with additional emission inventories to evaluate the accuracy.

Grewe, V., Frömming, C., Matthes, S., Brinkop, S., Ponater, M., Dietmüller, S., Jöckel, P., Garny, H., Tsati, E., Dahlmann, K., Søvde, O. A., Fuglestvedt, J., Berntsen, T. K., Shine, K. P., Irvine, E. A., Champougny, T., and Hullah, P.: Aircraft routing with minimal climate impact: the REACT4C climate cost function modelling approach (V1.0), Geoscientific Model Development, 7, 175–201, https://doi.org/10.5194/gmd-7-175-2014, 2014.

Grewe, V. and Stenke, A.: AirClim: an efficient tool for climate evaluation of aircraft technology, Atmospheric Chemistry and Physics, 8, 4621–4639, https://doi.org/10.5194/acp-8-4621-2008, 2008.

Dahlmann, K., Grewe, V., Frömming, C., and Burkhardt, U.: Can we reliably assess climate mitigation options for air traffic scenarios despite large uncertainties in atmospheric processes?, Transportation Research Part D, 46, 40-55, https://doi.org/10.1016/j.trd.2016.03.006, 2016.