Experimental investigation and modeling of thermal oxidation deposition of RP-3 jet fuel under high Reynolds number

Abstract

The modeling and numerical prediction of thermal oxidation deposition process under high heat flux and high Reynolds number are challenging. In this paper, experimental investigations on RP-3 jet fuel were carried out under wide range of wall heat flux (0.095–3.6 MW/m2), residence time (1.95–0.06 s), and inlet Reynolds number (522–5220). As turbulence intensified, the enhanced convective mass transfer transferred more precursors into the laminar sublayer to promote the formation of deposits, while the decreased residence time, the decreased laminar sublayer thickness, and the increased wall shear force inhibited the deposition process. These factors together led to the variation that the average deposition rate per unit fuel first decreased, then increased and decreased again in the later stage. Since current numerical methods ignored the effect of turbulence diffusion on mass transfer and the kinetic parameters of global reactions depicted the formation of SMORS and insoluble precursors were based on experimental data under low Reynolds number, it could not precisely simulate the promotion of insoluble precursors formation by enhanced convective mass transfer. Based on the experimental data, two functions were proposed to modify the convective mass transfer process of original numerical method. The error between the experimental data and the original simulated results could reach more than 500%, while the error decreased to less than 15% with the application of modified functions.