paraffin wax deposition and fouling

— ALf1 —
Equations L.7.4.3 and A7.6.2 were easily evaluated but
couation A7.b.4 nau to be solved by iteration and numerical
illtegraton.
Simpson’ a rule was used for the integration where
each interval was tacen in 10 steps. )her. was greater than 5
and less or equal to 26, the first approximation for u was that
of the previous distance y+_
The iteration was considered
completed when u changed by less than 0.001.
The subroutine was tested by evaluating u at isothermal
cOnc:ions.
That is, the viscosity was cept constant in ;ne
radial direction.
The results are shown in Table .o.2.4 and plotted
in fijre A8.2.4. At = 26 the subroutine gave u = 12.82 which
is exactly what it should be according to Deissler. figure
.o.2.4 snows tne nversa Velocity Pro:iie.
It was coaparea
wtn tne pro:lie given oy Deisser aa founa to concie.
.‘.82.6 Calculation of Di:nsioniess Temperature
Subroutine T?R0F calculated the dimensionless temperature
T+ using the equations
+
(a) y ‘ 2o
— dy
— 1 2+÷r 2 ++
÷nuy L1-exp(-n uy)J
j
..... (7.6.5)
(b) y > 26
= ]n + ..... (A7.5.3)
yl
Equation A7.6.3 was easily evaluated but equation A7,65
had to be integrated nu;erically using Simpson’s.rule. The sa.
mchod w.s used s for the evaluation of the dimensionless velocity,
except no iteration was required.