New experimental data of the convective heat transfer in
the spirally coiled tube under constant wall temperature are
presented. The numerical computations reveal the developments
and distributions of heat transfer and flow fields in
the spirally coiled tube. There is reasonable agreement
between the numerical results and the present experimental
data. In addition, the heat transfer and pressure drop
obtained from the spirally coiled tube are compared with
those from the straight tube. The secondary flow caused
by the centrifugal force has significant effect on the developments
and distributions temperature and flow in the spirally
coiled tube. Due to the centrifugal force, the Nusselt
number and pressure drop obtained from the spirally
coiled tube are 1.49, 1.50 times higher than those from
the straight tube, respectively.