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Calculation of the mean convective heat transfer coefficient kc of a helical pipe in a hydrodynamically developed laminar and turbulent flow regime.

Functions kc_overall and kc_overall_KC

There are basically three differences:

  • The function kc_overall is using kc_overall_KC but offers additional output variables like e.g. Reynolds number or Nusselt number and failure status (an output of 1 means that the function is not valid for the inputs).
  • Generally the function kc_overall_KC is numerically best used for the calculation of the mean convective heat transfer coefficient kc at known mass flow rate.
  • You can perform an inverse calculation from kc_overall_KC, where an unknown mass flow rate is calculated out of a given mean convective heat transfer coefficient kc

Geometry and Calculation

This heat transfer function enables a calculation of heat transfer coefficient for laminar and turbulent flow regime. The geometry, constant and fluid parameters of the function are the same as for kc_laminar and kc_turbulent.

The calculation conditions for laminar and turbulent flow is equal to the calculation in kc_laminar and kc_turbulent. A smooth transition between both functions is carried out between 2200 ≤ Re ≤ 30000 (see figure below).


The mean Nusselt number Nu representing the mean convective heat transfer coefficient kc is shown below for different numbers of turns n_nt at constant total length of the helical pipe.


The convective heat transfer of a helical pipe is enhanced compared to a straight pipe due to occurring turbulences resulting out of centrifugal forces. The higher the number of turns, the better is the convective heat transfer for the same length of a pipe.

Note that the ratio of hydraulic diameter to total length of helical pipe d_hyd/L has no remarkable influence on the coefficient of heat transfer kc.


Heat transfer and pressure drop in helically coiled tubes.. In 8th International Heat Transfer Conference, volume 6, pages 2847?2854, Washington,1986. Hemisphere.