A photo of a plane wing in the air with different connection graphics and a photo of Earth in the background.

Assessment of Contrail Formation via Combustion of Sustainable Aviation Fuel

Project number: 102
Category: Alternative Fuels

The goal of the project is to conduct experimental and modeling work to (1) understand the physics of contrail formation using advanced laser and optical diagnostics, (2) investigate contrail formation for fuels with varying composition, including Sustainable Aviation Fuels (SAF), and (3) integrate test data with environmental modeling teams and other flight-based tests. Contrails are composed primarily of water (in the form of ice crystals), and generally evaporate quickly. Under certain conditions however, contrails can persist and contribute to formation of clouds which can impact the temperature of the Earth’s atmosphere. Proactively mitigating this effect through either adjustments to the flight paths, engine technologies, or fuel composition is emerging as a critical area for research. A major gap in our understanding however is the fundamental physics of contrail formation at the molecular level. This project will strive to bridge this gap. The project will be carried out in close collaboration with NASA and Sandia National Laboratory (Livermore), whose work will complement this project.

Last Updated 8/23/2023


The main benefit of this project is to conduct highly controlled laboratory experiments coupled with high fidelity laser and optical diagnostics to create a scientific foundation for understanding contrail formation. This will help to systematically analyze data from larger scale tests such that using chase planes, an exercise that is challenging and expensive to carry out on a routine basis. Furthermore, by understanding the thermo-chemical pathways that lead to contrail formation, we can potentially predict the impact of SAF on contrail formation, and possibly new composition design guidelines for novel fuels in the future. Also, the data gained from such as study will allow us to inform engine technologies and modeling capabilities for routing airplanes on the most optimized flight paths. Additionally, the experimental efforts outlined in this study will also provide new insights on how to generate contrails in the laboratory and advanced diagnostics methods that will allow us to measure various aspects of the underlying physics.


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Program Managers