Effect of the fluid movement on heat exchange
: what is necessary to keep in mind
Here is, as a conclusion, the summary of all that was seen and
of what is to be kept in mind to understand convection. The convection
thermal resistance Rcv
is given by :

To reduce this, it is necessary to have the largest
effective heat-transferring surface area S
and the highest possible convective transfer coefficient h,
therefore this means to look for a flow having :
- a high fluid's thermal conductivity
- a high flow rate ...
- ... even better a more turbulent flow
- a high fluid's density and specific heat ( in fact their product
)
Recall of the physical properties of water and air :
Fluid |
k |
c |
r |
Water |
0.6 |
4180 |
1000 |
Air |
0.026 |
1006 |
1.2 |
In the light of that, which is the most interesting fluid ?
Water !
For this reason the interest in watercooling ;)
|