(b) From further research, you found that the Herschel-Bulkley model can be applied

to describe the rheological behavior of the formulated milk inks:

y = mx +c

S(Shear rate)

त्र

Stress

papa.s

where o is the shear stress (unit: Pa), oy is the yield stress (a constant, unit: Pa), K

is the flow consistency index (indicates the degree of viscosity, unit: Pa.s"), y is the

shear rate (unit: s¹), and n is the flow behavior index (n<1 indicates that the fluid

exhibits flow thinning behavior, n > 1 indicates that the fluid exhibits flow

thickening behavior, n = 1 indicates that the fluid is a Newtonian fluid).

i.

ii.

iii.

iv.

unit: Pa

0 = Øy +Kỷn

Shear

[MAS] Linearise the given Herschel-Bulkley model equation and hence,

determine the plot that will yield a straight line (i.e., determine the y-axis

variable, x-axis variable, gradient and the y-intercept in terms of the

(3 marks)

variables in the Herschel-Bulkley model equation).

[MAS] Based on the linearised equation in part (i), prepare a table with the

(2 marks)

correct values for the y-axis variable and the x-axis variable.

[DIAS] Plot a graph using the table of values in part (ii).

(5 marks)

[MAS] Obtain an equation from the plot in part (iii) and determine the

corresponding values of the flow consistency index, K and flow behavior

(2 marks)

index, n.