On Model Design of a Surrogate Fuel Formulation

Abstract

Calculations of evaporation characteristics (distillation curve, two-phase diagram, and critical points) of surrogates are described in detail. The efficiency of some surrogate blends, represented in literature, in reflecting the evaporation characteristics was analyzed. Based on the analysis, the chemical capabilities of surrogate models are not linked to their abilities to reflect the phase-equilibrium properties of real fuel. It is shown that model design of practical fuels must include the phase-equilibrium and distillation curve calculations. A surrogate mixture was selected, which closely matches the boiling-point curve and two-phase diagram for jet-A. Next, physical properties of reference fuel were taken into consideration: combustion enthalpy, formation enthalpy, molar weight, approximate formula (carbon per hydrogen ratio), sooting tendency index, critical point, two-phase diagram, and distillation curve.