Methods and tools for the characterisation of a generic jet fuel

Abstract

The demand for producing environmentally friendly jet fuels raises the question how to design a jet fuel that matches predefined properties. Targets to be matched are, e.g., energy content or less harmful emission characteristics. A further major challenge for the production of new synthetic jet fuels is their availability for the required certification process in sufficient quantities within an appropriate time frame and at reasonable cost. This implies the need for tools for the formulation of synthetic jet fuels which have mostly a component pattern that differs from Jet A-1 made from crude-oil. In the present work, to address these challenges, a new approach will be presented to be able to design a synthetic jet fuel from scratch with preselected and well-defined physical and chemical properties. The development of a chemical kinetic reaction mechanism able to describe the oxidation of a generic fuel consisting of only a few representative components of the major molecule classes occurring in jet fuels. n-Dodecane, cyclohexane, and isooctane were chosen as single fuel components, and their global combustion properties, i.e., laminar burning velocity and ignition delay time, were measured. These experimental data were used for the validation of the reaction mechanisms, first developed for each single fuel component, and then combined to the reaction mechanism for the generic fuel under consideration. The last step is the further optimization and reduction of the generic fuel reaction mechanism to ensure its suitability for the integration in numerical simulation to tackle the combustion of a synthetic fuel under practical conditions, e.g., in CFD simulations.