Accession Number : AD0758908

Title :   Anomalous Rheological Characteristics of a High-Internal-Phase-Ratio Emulsion.

Descriptive Note : Final rept. Jan 69-Mar 73,

Corporate Author : SOUTHWEST RESEARCH INST SAN ANTONIO TEX ARMY FUELS AND LUBRICANTS RESEARCH LAB

Personal Author(s) : Mannheimer,Richard J.

Report Date : MAR 1973

Pagination or Media Count : 21

Abstract : High-internal-phase-ratio emulsions containing 97 to 98 percent liquid fuel as the dispersed phase, are shown to exhibit complex rheological behavior including reversible work hardening and apparent slip-flow anomalies. However, when proper precautions are taken to prevent contamination by demulsified fuel, steady flow in glass and steel tubes is characterized by the Bingham model up to a critical wall shear stress. At higher stresses a discontinuity in the flow curve is observed. Experiments in different diameter tubes are used to establish that the critical stress is associated with the rupture of emulsion droplets and the formation of a thin film of fuel at the wall of the tube. The apparent absence of a yield value and critical stress with PTFE (Polytetrafluoroethylene) tubes indicates that the film of fuel forms when the emulsion contacts a hydrophobic surface. (Author)

Descriptors :   (*JET ENGINE FUELS, COLLOIDS), (*COLLOIDS, *RHEOLOGY), FLUID FLOW, CAPILLARY TUBES, STAINLESS STEEL, HALOCARBON PLASTICS, NUMERICAL ANALYSIS, SHEAR STRESSES, DEGRADATION

Subject Categories : Physical Chemistry
      Fluid Mechanics
      Fuels

Distribution Statement : APPROVED FOR PUBLIC RELEASE