A	Local area	mm2
Af	Wetted surface area of the MPFHS	mm2
As	Total base area of MCHS	mm2
Cp	Specific heat capacity	J·kg−1·K−1
cp,f	Specific heat capacity of fluid	J·kg−1·K−1
Dh	Hydraulic diameter	mm
df	Diameter of fin	mm
f	Friction factor
hi,x	Local heat transfer coefficient	W·m−2·K−1
Hc	Height of microchannel	μm
Hf	Height of fin	μm
Hs	Height of substrate	μm
kf	Thermal conductivity of fluid	W·m−2·K−1
ks	Thermal conductivity of solid	W·m−2·K−1
L	Length of the microchannel	mm
$\stackrel{·}{m}$	Mass flux rate of water	kg·s−1
Nu	Nusselt number
Nux	Local Nusselt number
P	Pressure	Pa
Q	Volumetric flow rate of fluid	mL/min
q	Local heat flux	W·m−2
Rconv	Average thermal resistance of convection	K/W
Re	Reynolds number
Ta,f	Volume-weighted average temperature of fluid part	K
Ta,s	Volume-weighted average temperature of solid part	K
Tf	Temperature of fluid	K
Ti	Inlet temperature of fluid	K
To	Inlet temperature of fluid	K
Ts	Temperature of solid	K
u	Flow velocity	m·s−1
umax	Maximum flow velocity	m·s−1
$\overrightarrow{V}$	Velocity vector	m·s−1
Vf	Fluid volume of the MPFHS	mm3
vyz	Secondary flow velocity	m·s−1
WH	Width of single unit cell in MPFHS	μm
Greek symbols
α	Inclined angle	°
μ	Viscosity	Pa∙s
ρ	Density	kg·m−3
ΔP	Pressure difference	Pa