Jet engine turbine (3D xray blue transparent)

Characterization of Compositional Effects on Dielectric Constant

Project Number: 089
Category: Alternative Jet Fuel

The goal of this new project is to characterize the compositional effects of jet fuels on dielectric constant. Dielectric constant is a key fuel property, critical for fuel gauging systems. The project will work with original equipment manufacturers (OEM) and groups advancing novel dielectric testing methods to advance the current understanding of dielectric constant and fuel composition relations. The program will update test methods as needed to accommodate changing fuel compositions as novel jet fuels are developed to meet the growing need for sustainable aviation fuels (SAF). This research also reflects the desire to move beyond current SAF blend limits as specified in ASTM D7566 annexes, most of which are limited to a maximum of 50% by volume blend with conventional jet fuel. To move to greater blend volumes of SAF with conventional jet, including up to 100% SAF that does not need to be blended with conventional jet fuel, issues regarding dielectric constant must be resolved.


This research effort will determine the effect of jet fuel composition on dielectric constant, a critical fuel property to ensure safe operations. This project has been developed in response to a critical need identified by both the aviation OEM community and ASTM International stakeholders involved in the jet fuel qualification process. Some novel fuels with unique fuel compositions and dielectric constants outside of the jet fuel experience range raised questions with some OEMs with regard to the ability to accurately gauge fuel volumes using their existing systems. This work will facilitate efforts to approve a 100% SAF standard within ASTM International, the organization that manages domestic jet fuel specifications. The resulting knowledge gained will inform aviation OEMs and jet fuel producers as both seek to ensure safety and performance of novel jet fuels with existing and future aircraft. This program will inform whether updates to dielectric testing methods are needed.

Last updated 7/20/2023

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