DOI: 10.1615/ICHMT.2008.CHT
ISBN Print: 978-1-56700-253-9
ISSN: 2578-5486
HEAT TRANSFER IN THIN LIQUID FILMS FLOWING DOWN HEATED INCLINED GROOVED PLATES
Краткое описание
Thin liquid films flowing down vertical or inclined plates are widely used in many industrial apparatuses. Using structured plate surfaces often leads to heat transfer enhancement.
In the present work a numerical model for heat transfer in a thin liquid film flowing down a heated inclined grooved plate is developed. To this end, the Graetz-Nusselt problem for falling films on structured plates is solved. The computed velocity field, the developed temperature field as well as the temperature distribution in the thermal entrance region of a falling film are presented. The dependence of temperature distribution on the Reynolds number, the Biot number, the applied heat flux, the plate inclination angle and the plate topography is explored. It is shown that the film rupture on the groove crests at relatively high heat fluxes observed in experiments can be attributed to the strong interface temperature gradients developed in the thermal entrance region. The effect of the temperature gradients on film stability is also investigated.
To qualitatively validate the numerical model the hydrodynamics and heat transfer in falling films on structured plates is studied experimentally. The numerical results are discussed and compared with the experimental results.