Numerical investigation on influences of inlet flow pattern on RP-3 thermal oxidation deposition

The influences of inlet flow pattern on thermal oxidation deposition of RP-3 kerosene were numerically investigated in a horizontal tube under a supercritical pressure of 5 MPa in the temperature range of 300–750 K using a computational fluid dynamics (CFD) model. The developed CFD model was based on a pseudo-detailed chemical kinetics mechanism coupled with fuel flow and heat transfer. The obtained results indicated that reactant starvation and mass diffusion controlled the deposition process. The deposition rate peak was concluded as the criterion. As the inlet Reynolds number increased, the process gradually transformed from a starvation-controlled one to a diffusion-controlled one. The inlet Reynolds number exhibited little effect on the initial deposition position, but the peak position moved downstream by accelerating reactants transfer in axial direction with an increasing inlet Reynolds number. The precursor concentration at outlet increased more than 100 times as the inlet Reynolds number increased from 625 to 12500. For laminar and transition flows at inlet, the total mass of deposition and deposition rate peak values were approximately proportional to mass flow rate, and the surface average deposition rate agreed exponential relationship with inlet Reynolds number. When the inlet flow was fully developed turbulent, the deposition amount and surface average deposition rate increased slightly.