Publications Repository - Gdańsk University of Technology

In the paper a method developed earlier by authors is applied to calculations of pressure drop and heat transfer coefficient for boiling flow and condensation flow with account of non- adiabatic effects for some recent data collected from literature. The first effect, the modification of interface shear stresses in annular flow pattern is considered through incorporation of the so called "blowing parameter". The mechanism of modification of shear stresses at the vapor-liquid interface for such case has been presented in detail in the paper. In case of annular flow it contributes to thickening and thinning of the liquid film, which corresponds to condensation and boiling respectively. There is also another influence of the wall heat flux, where it is influencing the bubble nucleation in the case of the bubbly flow pattern. As a result a modified general form of the two-phase flow multiplier, applicable both to boiling flow and condensation flow, is obtained, in which the non-adiabatic effects are clearly pronounced. Obtained model of two-phase multiplier, incorporating the non-adiabatic effects is additionally used in predictions of heat transfer coefficient.

Authors

• prof. dr hab. inż. Dariusz Mikielewicz link open in new tab ,
• dr hab. inż. Rafał Andrzejczyk link open in new tab ,
• dr inż. Blanka Jakubowska link open in new tab ,
• Jarosław Mikielewicz link open in new tab