A c	Upstream interception area
A(s)	Function of far-field approaching
B	Width of deformed droplets
a, b	Adjustable dimensionless parameters of Equation (34)
ac, am	Parameters of Equation (64)
C(i, j):	Coagulation kernel—Equation (1)
C	Ratio of circulation length and droplet distance—Equation (33)
Ca	Capillary number Equation (2)
Cac	critical c.n.
C H	Parameter of coalescence in a blend—Equation (62)
D	Droplet deformation—Equation (7)
D*	Dimensionless function in Equation (37)
E	Rate of strain tensor
E DK	Volume energy—Equation (58)
F(i)	Overall breakup frequency—Equation (1)
F	Drag force
F c	Driving force of the coalescence—Equation (29); FS in shear flow; Fe in uniaxial extension
f	General functions—Figure 3; not the same in Equation (23); another fF in Equation (61)
h	Distance between droplets surfaces
h c	critical distance
G’	Storage modulus
G’m	s.m. of matrix
G’d	s.m. of the dispersed phase
g(m)	Function defined by Equation (31)
g(p)	function defined by Equation (66)
I	Unit second-order tensor
J	Rate of coalescence
J 0	r.c. without interdroplet interactions
K(p, Λ)	Function in Equations (36) and (37)
k i	Parameters in Equations (15b) and (64)
L	Length of deformed droplets
m	Parameter defined by Equation (32)
m	Orientation vectors
n	Number of droplets
ni, nj	of radius Ri, Rj
n k	of volume V1—Equation (1)
n	Number of spherical droplets in a volume unit—Equation (57)
n f	Number of fragments/daughter droplets
nf(i)	formed at breakup of a droplet of volume iV1
n	Outward unit normal to the spherical contact surface
N1,d, N1,m	The first-normal stress differences of the droplets and matrix
P c	Collision efficiency
p	Ratio of disperged phase and matrix viscosity ηd/ηm
q	The growth rate
R	Droplet radius
R c	critical d.r. for breakup
R* = R/Rc	reduced d.r.
R 0	r. of parent droplet
R f	r. of formed droplets
R d	r. of daughter droplets
R eq	equivalent d.r. def. by Equation (35)
R L	r. of steep decrease in Pc
R F	parameter of Equation (51)
r	The vector from the center of droplet 1 to the center of droplet 2
r 0	Initial thread radius
r f	Radius of flattened part of a droplet—Equation (29)
S	Surface
s	Dimensionless center-to-center distance s = r/R
t	Time
t B	Breakup t.
t s	Local minimum of Equation (20)
t g	t. needed for the growth of α to its critical value
t c	t. of coalescence
t i	interaction t.
tB*	Dimensionless breakup time
u	Velocity of a particle
v	Velocity
v12(r)	relative velocity of colliding droplets
V 1	Elementary volume
x, y, z	Spatial Cartesian coordinates
x	2πR/λ —Equation (20)
x m	Dominant wave number Equation (23)
α(t)	Distortion amplitude at time t
α 0	initial d.a.
β	Parameter in Equations (44)–(46)
$\dot{\mathit{\gamma }}$	Shear rate
$\dot{\mathit{\gamma }}$ eff	effective s.r.
$\dot{\epsilon }$	Stretching rate
ζ	Friction resistance
η	Viscosity
η m	matrix v.
η d	droplets/dispersed phase v.
η ap	apparent v. of the blend
θ	Polar angle
Λ	Ratio of radii of smaller to larger droplet
λ	Wavelength of droplet breakup
λ m	dominant w.; λ0 at t = 0
λ r	Ratio of the magnitude of the strain rate tensor to the sum of magnitudes of the strain rate and vorticity tensors
μ	Parameter of Equation (66)
σ	Interfacial tension
σ ef	effective if.t.
τ m	Relaxation time
$\Phi (x,p)$, $\overline{\Phi }(x,p)$	Functions in Equation (20) defined in [7]
φ	Azimuth
ϕ	Volume fraction of the dispersed phase
Ψ (λ, p)	Function in Equation (17)
Ω	Angular velocity tensor
ω(i, j)	Probability that a fragment formed by the breakup of a droplet of volume jV1 will have volume iV1
EPR	Ethylene-propylene rubber
PCL	Poly(caprolactone)
PLA	Poly(lactic acid)
PP	Polypropylene