SINOPSIS

In this review shear stress effects upon condensation heat transfer in tubes with counter current flow of vapour and liquid film is presented. This has been done starting from Nusselt's theory which has been published 90 years ago. The open literature of the past 10 to 15 years has been scanned with respect to contributions in 3 fields, namely condensation of (a) pure vapours, (b) pure vapours mixed with non-condensable gases and (c) condensable vapour mixtures. Lots of analytical and experimental results are found for the first field where the physical behaviour is close to a final formulation including all effects on heat transfer. The second field is highly interesting with respect to pressurized water reactor accidents with big research programs being in progress. Much has to be done before condensation heat transfer under these conditions can be treated as a solved problem. In the third field, i.e. condensation of mixtures, only a few publications have been found which are of a more or less tentative character. Summarizing it can be noted that Nusselt's theory didn't loose anything of its fascinating character which is based on its simplicity on one side and its outstanding success within the limits of assumptions on the other side. Most of the recent investigations refer measured condensation heat transfer coeffcients to Nusselt's solution, and it is still used in actually developed correlations together with degradation and enhancement factors respectively.