Study of heat transfer coefficient in helical coil
U, W·m-2·K-1
600 Unsteady state 618 rpm
Steady state 1703 rpm
550
Unsteady state 1703 rpm
500
450
400
150020002500300035004000
Re
Figure 12: Comparison of steady state and unsteady state heat transfer coefficient at agitations
of 618 rpm and 1703 rpm.
When the results of steady state and unsteady state experiments are compared with the
constant agitation rate of 618 rpm, the percentage difference between them at the Reynolds
number of 1993 is 15%. When the Re is 2628, the percentage difference is 5%, With the
annaabi.ee 
