1 9 6 D O C . 4 2 C O M M E N T O N P A P E R B Y H E S S
44. “Comment on the Paper by W. R. Heß,
‘Contribution to the Theory of the
Viscosity of Heterogeneous Systems’”
[Einstein 1920g]
Received 3 August 1920
Published September 1920
In: Kolloid-Zeitschrift 27 (1920): 137.
In my 1906 dissertation I derived by a theoretical method the formula
(1)
for the viscosity of a suspension of rigid spheres in a fluid of viscosity
where is the total volume of the suspended spheres per unit volume of suspen-
sion.
Motivated by J. Perrin’s experiments, I revised my calculations a few years
later and found an error in my calculation.—The correct formula is (Ann. d. Phys.
4, 34, 1911):
(2)
It appears that none of the people working in this field has noticed this correc-
tion. It should be noted that the factor 2.5 in this formula (for a diluted suspension
of rigid spheres) is rigorously derived from the hydrodynamic equations of
motion.
[1]
[2]
[3]
η′ η( 1 ϕ) + =
η′ η,
ϕ
[4]
[5]
η′ η( 1 2.5ϕ). + =