ABSTRACT
A numerical three-dimensional flow and conjugate heat transfer in circular minichannel-based multi-row heat sink is presented in this article. Effects of geometrical parameters including channel dimensions, channel arrangements (inline or staggered), and the number of channel rows with a single-pass flow on the thermal performance of the heat sink are presented. The determination of the bottom surface temperature, average heat transfer coefficient, thermal resistance as well as the pressure drop was reported. The number of rows and the diameter of the circular channel for a constant Reynolds number were found to have a remarkable cooling effect on the heat sink. It was found out that in the case of using four channel rows with the channel diameter of 1 mm, the cooling capacity is 88.5 W/cm2 compared to 28 W/cm2 for a single row 1 mm diameter.
Nomenclature
d | = | circular minichannel diameter, m |
dh | = | hydraulic diameter of channel, , m |
h | = | heat transfer coefficient, W/m2 · K |
k | = | thermal conductivity, W/m · K |
L | = | length of minichannel heat sink, m |
Nu | = | local Nusselt number |
P | = | pressure, Pa |
Pe | = | Peclet number |
Pr | = | Prandtl number |
qi | = | input heat flux, W/m2 |
Re | = | Reynolds number |
Rh,s | = | thermal resistance, m2 · °C/W |
r, θ, z | = | cylindrical coordinates |
T | = | temperature, °C |
Tf,in | = | inlet fluid temperature, °C |
V | = | velocity, m/s |
W | = | width of minichannel heat sink, m |
x, y, z | = | Cartesian coordinates |
Greek symbols | = | |
μ | = | dynamic viscosity, Pa.s |
ρ | = | density, kg/m3 |
ν | = | kinematic viscosity, ν = µ/ρ |
Subscripts | = | |
av | = | average |
in | = | inlet |
f | = | fluid |
s | = | solid |
Nomenclature
d | = | circular minichannel diameter, m |
dh | = | hydraulic diameter of channel, , m |
h | = | heat transfer coefficient, W/m2 · K |
k | = | thermal conductivity, W/m · K |
L | = | length of minichannel heat sink, m |
Nu | = | local Nusselt number |
P | = | pressure, Pa |
Pe | = | Peclet number |
Pr | = | Prandtl number |
qi | = | input heat flux, W/m2 |
Re | = | Reynolds number |
Rh,s | = | thermal resistance, m2 · °C/W |
r, θ, z | = | cylindrical coordinates |
T | = | temperature, °C |
Tf,in | = | inlet fluid temperature, °C |
V | = | velocity, m/s |
W | = | width of minichannel heat sink, m |
x, y, z | = | Cartesian coordinates |
Greek symbols | = | |
μ | = | dynamic viscosity, Pa.s |
ρ | = | density, kg/m3 |
ν | = | kinematic viscosity, ν = µ/ρ |
Subscripts | = | |
av | = | average |
in | = | inlet |
f | = | fluid |
s | = | solid |
Acknowledgments
The authors would like to acknowledge Egyptian Japanese University for Science and Technology (EJUST) for their support by licensed ANSYS FLUENT 12 software to be used to carry out the numerical calculation for comparison.