P. K. Sarma

Turbulent film condensation on a horizontal tube with external flow of pure vapors

Abstract The problem of condensation of vapors flowing with high velocity around a horizontal tube is solved for the case of isothermal condition of the wall of a condenser tube. The interfacial shear at the vapor conderLsate film is assessed with the help of Colburn analogy. Extension of these results in the estimation of average condensation heat transfer coefficients is found to be successful. The present theoretical results are further compared with the recent experimental data and the agreement between the two is found to be very satisfactory.

Turbulent film boiling on a horizontal cylinder

Abstract The turbulent film boiling on a horizontal cylinder is formulated and solved giving due importance to thermal radiation. In the analysis the test surface is maintained under isothermal conditions and the thermophysical property variation of the vapor due to the steep temperature gradients in the vapor boundary layer is included in the formulation. The analysis is checked with some experimental data relevant to turbulent film boiling. The agreement between the two is found to be very satisfactory.

Turbulent film boiling on a horizontal cylinder : Effect of temperature dependent properties

The turbulent film boiling from a horizontal cylinder is theoretically investigated considering the properties of the vapor as temperature dependent. In addition the effect of the thermal radiation from the surface of the cylinder on the film boiling heat transfer coefficients is studied. Some of the two-phase boundary layer characteristics are established. Comparison of the results from the present theory with relevant experimental data revealed very satisfactory agreement. An equation is proposed from the computational results with the aid of regression.

Heat transfer to non-newtonian laminar falling liquid films with smooth wave free gas—liquid interface

Abstract The present paper investigates analytically the problem of heat transfer to a non-Newtonian laminar falling liquid film flowing along an inclined wall for the thermally developing and thermally developed regions. In the developing region of the temperature profile, the Nusselt number decreases monotonically until the thermal boundary layer touches the interface. But immediately after this point, the liquid film thickness decreases as well as the temperature difference in the film. The influence of parameters such as α (i.e. Fr/Remod ratio), γ (i.e. modified form of ϱμ), modified Prandtl number and the flow behaviour index “n’ on heat transfer results is also presented.