ABSTRACT
The paper presents a comprehensive experimental study on emulsion (oil-in-water) fluid flow
through curved diffusers. The experimental setup has been designed and constructed in the
fluid mechanics laboratory of the faculty of engineering, Menoufiya University to perform the
measurements which have been carried out on five models of curved diffusers. The
measurements of pressure distributions along the outer and inner walls of the curved diffuser
have been performed for different area ratios, different curvature ratios (ratio of centerline
arc radius to inlet width), different inflow Reynolds numbers and different emulsion holdup
(ratio of oil volume to emulsion volume), while the oil concentration has been varied from 0%
to 20% by volume. The experimental work has been carried out using two sets of oil-in-water
emulsions; the first is stable oil-in-water (o/w) emulsion using Sodium Dodecyl Sulfate (SDS)
emulsifier and the second is unstable o/w emulsion at different holdup values. The energyloss
coefficients for each model are based on detailed measurements of the wall pressure
distributions along walls of the curved-diffuser models including long upstream and
downstream tangents. The energy-loss coefficient data have been plotted versus of
Reynolds number at different concentrations.
New results on energy-loss coefficient during flow of unstable and stable oil-in-water
emulsions through curved diffusers have been reported in the present paper. The diffuser
energy-loss coefficient is strongly affected by the geometrical parameters of diffuser,
Reynolds number and emulsion holdup. Generally for the flow in curved diffusers, the
resistance coefficients for stable and unstable (oil-in-water) emulsions are higher than that of
pure-water flow. It is also noticed that the unstable o/w emulsion exhibits lower values in loss
coefficient compared with that given for stable o/w emulsion.
General correlation of the loss coefficient (not previously considered) for the present cases
exploring the ranges of geometrical parameters, inflow condition and Reynolds number
conditions is extracted from the present experimental study.