https://trid.trb.org/ en-us Copyright © 2026. National Academy of Sciences. All rights reserved. http://blogs.law.harvard.edu/tech/rss tris-trb@nas.edu (Bill McLeod) tris-trb@nas.edu (Bill McLeod) https://trid.trb.org/Images/PageHeader-wTitle.jpg https://trid.trb.org/ https://trid.trb.org/View/2628234 Tue, 03 Feb 2026 10:07:07 GMT https://trid.trb.org/View/2628234 https://trid.trb.org/View/2603812 Thu, 20 Nov 2025 17:07:20 GMT https://trid.trb.org/View/2603812 https://trid.trb.org/View/2582187 Fri, 24 Oct 2025 16:53:56 GMT https://trid.trb.org/View/2582187 https://trid.trb.org/View/2578896 Fri, 26 Sep 2025 13:39:57 GMT https://trid.trb.org/View/2578896 https://trid.trb.org/View/2566027 Mon, 25 Aug 2025 12:24:33 GMT https://trid.trb.org/View/2566027 https://trid.trb.org/View/2548107 80 %) of global warming contrail climate forcing. Hence, the targeted use of low contrail kerosene on those flights appears promising. But, such an approach would require additional operational efforts, such as a duplication of supply lines and storage tanks. This study evaluates the feasibility and operational efforts of a segregated supply of a 35 m-% SAF-blend (14.34 m-% hydrogen content) to 84 winter time demonstration flights to reduce contrail climate forcing. Between 17th January 2023 and 2nd February 2023, low contrail kerosene was supplied to commercial A320 type aircraft flights on the route between Stockholm and Copenhagen in northern Europe. The operational feasibility and related efforts to target flights with the highest contrail energy forcing as well as a large-scale application are described. The evolution of contrails is tracked using data from the Meteosat Second Generation (MSG) satellite. The contrail energy forcing is calculated for the corresponding flight trajectories assuming another, well-validated engine model (CFM56–5B4 for the simulations instead of LEAP1A-26 for the demonstration flights) using the Contrail Cirrus Prediction (CoCiP) model with meteorological input fields from European Reanalysis data (ERA5). For the first time, the experiment demonstrates the operational feasibility for a segregated supply of low contrail kerosene to medium range aircraft at Stockholm airport. The segregated supply of low contrail kerosene can be realized for short to medium range flights, which can be fueled by a refueller truck. Targeting individual flights via single line hydrant fueling systems seems impractical as of now. Operational efforts to target single flights with highest contrail energy forcing are almost identical to the efforts in this demonstration experiment. Simulations estimate that the segregated supply of the medium blend kerosene (14.34 m-% hydrogen content) can reduce contrail energy forcing by about 11 % assuming the use of a “Rich-Quench-Lean” (RQL) engine (CFM56–5B4). The contrail climate benefit increases to >20 % for a 50 % blend ratio (14.7 m-% hydrogen content). Also, the location and evolution of the demonstration flights’ 28 contrails calculated with CoCiP was tracked with satellite data. The uncertainty of absolute contrail climate forcing estimates is mainly limited due to meteorological data input and also by lacking information on fuel composition in terms of cycloalkane, mono- and polycyclic aromatics content. Contrarily, the uncertainty of relative changes in contrail climate forcing is subject to low uncertainty, since it compares the use of different fuels for an identical fleet and identical weather conditions.]]> Wed, 09 Jul 2025 13:59:31 GMT https://trid.trb.org/View/2548107 https://trid.trb.org/View/2571625 Tue, 08 Jul 2025 10:45:50 GMT https://trid.trb.org/View/2571625 https://trid.trb.org/View/2571720 Tue, 08 Jul 2025 10:41:05 GMT https://trid.trb.org/View/2571720 https://trid.trb.org/View/2511010 FT-SPK > HEFA-Camelina. To evaluate the impact of iso-paraffins on sooting tendency and validate the suitability of utilizing binary blends of iso-dodecane (iC12) and normal dodecane (nC12) as surrogates for emulating sooting characteristics of SAFs, an experimental study was conducted to measure the soot volume fraction profiles of iC12/nC12 blends with varying blending ratios in the counterflow non-premixed flame configuration using laser-induced incandescence technique. It is shown that ATJ and HEFA-Camelina can be well-represented by pure iC12 and the blend of 25% iC12 and 75% nC12 (in liquid volume), respectively. At high (low) reactant concentrations, the blend of 75% iC12/25% nC12 (90% iC12/10% nC12) exhibits similar sooting characteristics of FT-SPK. The present experimental results indicate that binary blends of iC12 and nC12 have the potential to serve as effective surrogates for SAFs, as they are predominantly composed of these two types of paraffinic components. Furthermore, it is found that when the iC12 blending ratio exceeds 90%, the maximum soot volume fraction exhibits a stronger nonlinear increase. This experimentally observed nonlinearity in maximum soot volume fraction with increasing alkane branching in the binary fuel blend signifies the importance of fuel molecular structure effects on soot formation pathways in counterflow non-premixed flames. ]]> Tue, 18 Feb 2025 14:55:37 GMT https://trid.trb.org/View/2511010 https://trid.trb.org/View/2448910 Wed, 27 Nov 2024 13:43:40 GMT https://trid.trb.org/View/2448910 https://trid.trb.org/View/2408803 Wed, 18 Sep 2024 09:41:17 GMT https://trid.trb.org/View/2408803 https://trid.trb.org/View/2361914 Tue, 09 Apr 2024 09:22:01 GMT https://trid.trb.org/View/2361914 https://trid.trb.org/View/2361916 Mon, 08 Apr 2024 09:14:53 GMT https://trid.trb.org/View/2361916 https://trid.trb.org/View/2270196 Mon, 13 Nov 2023 16:57:37 GMT https://trid.trb.org/View/2270196 https://trid.trb.org/View/2247642 Mon, 16 Oct 2023 17:26:23 GMT https://trid.trb.org/View/2247642