$L$	length of the microchannel, m
$W_s$	width of the silicon basement, m
$H_s$	height of the silicon basement, m
$W_f$	width of the microchannel, m
$H_f$	height of the microchannel, m
$u_{in}$	velocity component at the microchannel inlet, m/s
$T_f$	temperature of the fluid, K
$T_{in}$	temperature at the microchannel inlet, K
$p_f$	static pressure of the fluid, Pa
$p_{out}$	static pressure at the microchannel outlet. Pa
$u$	velocity component in the $x$ direction, m/s
$v$	velocity component in the $y$ direction, m/s
$w$	velocity component in the $z$ direction, m/s
$T_s$	temperature of the silicon basement, K
$q_w$	heat flux per area, W/${\mathrm{m}}^2$
$s$	cavity spacing, m
$L_c$	longitudinal length of a single cavity, m
$H_c$	height of a single cavity, m
$W_c$	total width of the microchannel plus cavities, m
$x, y, z$	three coordinates shown in Figure 1, m
$\rho$	density, kg/m3
${\mu }_f$	dynamic viscosity, Pa s
$C_{pf}$	specific heat of fluid, J Kg−1 K−1
$k_f$	thermal conductivity of fluid, W m−1 K−1
$k_{s }$	thermal conductivity of silicon, W m−1 K−1
Re	Reynolds number
f	friction factor
Nu	Nusselt number
Ƞ	thermal enhancement factor
$u_m$	average velocity, m/s
$D_h$	hydraulic diameter, m
$∆p$	pressure drop, Pa
h	heat transfer coefficient, W m−2 K−1
$A$	area of contact surface between the fluid zone and solid zone
n	local coordinate normal to the wall
AR	aspect ratio
$f_{FD}$	friction factor of fully developed flow