Effects of eddy diffusivity in film condensation on a horizontal tube

It is an investigation into turbulent film condensation on a horizontal tube. In order to forecast the results more exactly, a new theory model of local film shear stress (τ / τw) is presented in the paper. In the study, four models of different eddy diffusivity are considered. The numerical calculation is obtained by using Visual C++. The result shows that among the four models, the difference between the higher value and the lower value of the mean Nusselt number is about 10.1%. Besides, the results developed in the current study are compared with those generated by previous theoretical results. The result shows that the present paper considering film local shear has a higher mean Nusselt number than the previous ones that exclude the film local shear.