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Monster Media 1996 #14
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Monster Media No. 14 (April 1996) (Monster Media, Inc.).ISO
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mixing10.zip
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LIQUID.TXT
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METHODOLOGY
LIQUID MIXTURE PROPERTIES
The mixing calculations are done on the composite blend
mixture. The properties of this blend mixture are calculated
from the properties of two liquid phases by the mixing rules
given below. The method assumes that the two liquid phases
are completely miscible.
In the following equations the properties of the Bulk fluid
is denoted by the letter B. The properties of the Disperse
phase uses the letter D. and the Mix phase uses the letter M.
MIXTURE VOLUME
The volume of the mix phase is determined by adding the
volume of the Bulk and the Disperse phase.
Mvol = Bvol + Dvol
MIXTURE DENSITY
The density of the mixed phase is determined by the
volumetric average of the density of the two phases.
Mden = (Bvol*Bden + Dvol*Dden)/ Mvol
MIXTURE VISCOSITY
The mixture viscosity is calculated by an computerized
adaptation of the ASTM method using blending indexes. The
viscosity of the mixture if calculated by hand would follow
the method shown in J.B. Maxwell's Data Book on Hydrocarbons
Section 9 using ASTM standard Viscosity-Temperature Charts
for liquid Petroleum Products (D341-39) Charts C and D.
The Blending Index for each fraction is determined from its
viscosity at the mix temperature. The blending indexes are
additive by volume fractions, and the resulting sum may be
converted to the viscosity of the mixture by referring to the
blending chart again.
The computerized adaption of this method uses the following
relationships, derived from the chart.
Visc = 10^(10.22602 - 5.81024 log BI) for viscosity > 10cp
Visc = 10^(6.55958 - 3.50779 log BI ) for viscosity < 10 cp
MIXTURE HEAT CAPACITY
The heat capacity of the mixture is calculated by a weight
average of the heat capacity of the bulk and disperse phase.
MIXTURE THERMAL CONDUCTIVITY
The mixture thermal conducitivity is calculated by a weight
average of the thermal conductivities of the bulk and
disperse phases. This the API recommended procedure No
12A2.1
MIXTURE SURFACE TENSION
The mixture surface tension is calcuated by taking a volume
average of the bulk and disperse phases.
The method of Morgan and Griggs referred to in the API data
book and in the JOURNAL OF AM CHEM SOC 39,2261(1917)
recommends calculating the surface tension from a molal
average. Other methods using Parachlors and group
contributions also exist. Probably none are very accurate.