DIE-SWELL OF ANTIMISTING KEROSENE: PART 1. SHEAR AND NORMAL STRESSES OF ANTIMISTING KEROSENE AT HIGH SHEAR RATES DETERMINED FROM DIE-SWELL AND TORSIONAL BALANCE MEASUREMENTS

Abstract

Die-swell and torsional balance experiments were performed to measure the shear and normal stresses developed by AMK (0.3% FM-9 + glycol/amine in Jet A) and 0.1% ARCO in Jet A. Capillary tube experiments show that AMK shear thickens at a critical shear rate, reaches a maximum viscosity and then shear thins at higher shear rates. Despite the fact that the antimisting fuel made with the ARCO polymer exhibits a more conventional shear stress dependency (i.e., shear thinning), die-swell measurements indicate that both fuels develop large normal stresses at high shear rates. While the torsional balance method was able to obtain both shear and normal stress information for the ARCO polymer at high shear rates, AMK exhibited anomalous behavior that made it impractical to measure normal stresses by this method. A comparison of normal stresses for the ARCO polymer indicates that normal stresses measured by these two methods differ significantly in magnitude.