Electric field effects on thermal oxidation deposition of aviation kerosene

Abstract

Aiming at solving the problem of carbon deposition in aero-engine fuel nozzles, this study presents a method of arranging cylindrical electrode in fuel feed arm to inhibit thermal oxidation deposition. Based on the electrohydrodynamics (EHD) technique, the effect of electric field on fuel’s original flow, heat transfer and oxidation deposition reaction process was investigated. A 3D mathematical model was established based on the Maxwell, Navier Stokes (NS) and species transport equations. The finite volume method was used for conservative discretization of the governing equations. The oxidation deposition behavior of aviation kerosene in fuel feed arm under different mass flow and voltage conditions was investigated. The results show that, in the absence of electric field, the deposition in the fuel feed arm mainly comes from the surface reaction caused by the diffusion of insoluble precursor (InsolubleAH) from the thermal boundary layer to the wetted wall. The secondary flows generated by the electric field break the original flow and thermal boundary layer, which can reduce the temperature gradient of the fuel near the wall and inhibit the generation of insoluble deposition precursor in the volumetric reaction. Furthermore, driven by electric field force, the mainstream fuel fully cooled the wetted wall thus inhibiting the wall surface reaction. The average deposition rate was reduced up to 30.9%. This study provides a new means of inhibiting oxidation deposition in fuel injection system.