000 03113nam a22001697a 4500
082 _a621.402
_bD197H
100 _aDandotiya, Deepak
_926383
245 _aHydrodynamic and Thermal Analysis of Vertical Falling Film with Flash Evaporation
_cby Deepak Dandotiya
260 _aIIT Jodhpur
_bDepartment of Mechanical Engineering
_c2019
300 _axvi,51p.
_bHB
520 _a"Liquid film falling under the effect of gravity is confronted in industrial two-phase flowapplications such as distillation columns and reactors. Theoretical treatment of hydrodynamicand thermal boundary layer during vertical film flow over a flat plate is well-studied problem.All the existing studies, deal with development of these two boundary layers from the solidsurface of the flat plate. The hydrodynamic boundary layer is intuitively attached with the flatsurface, but, depending on heat transfer orientation, thermal boundary layer can develop from flatsurface as well as the free surface of the film. Thermal boundary layer developed from the freesurface is hardly studied till date. In the present work the hydrodynamic and thermal boundarylayer analysis of the vertical falling film due to heat transfer from free surface has been studied.The semi-analytical models for hydrodynamic and thermal boundary layers are postulated usingReynold’s transport theorem (RTT). For hydrodynamic analysis, the RTT form of momentum andcontinuity equation is solved analytically. The estimated velocity profile from hydrodynamicanalysis serves as the input for heat transfer analysis. Evidently one way coupling has beenused to relate hydrodynamic and thermal features. The thermal analysis requires the input fromhydrodynamic analysis, while the hydrodynamic model is a standalone scheme without anydependence on thermal field. The non-dimensional film thickness variation along the verticaldistance at different flow rate is obtained using the analytical hydrodynamic model and comparedwith the results from existing literatures. The one way coupled heat transfer analysis is performedfor two different scenarios. The first thermal problem involves convective heat loss from thefree surface. The second thermal problem describes heat transfer from the free surface due toflash evaporation. During flash evaporation, the flowing film is exposed to low ambient pressurecausing rapid evaporation from the film surface. The latent heat of evaporation is absorbed fromthe film itself, rendering rapid cooling of the film. For both thermal analyses, the thermal boundarycondition at the solid wall is considered to be adiabatic. To determine the effect of heat transferfrom the free surface due to either convection or rapid evaporation, we solved RTT form of energyequation and determined the variation of thermal boundary layer thickness, surface temperatureand vertical distance to achieve thermally fully-developed film. "
650 _aHydrodynamic and Thermal Analysis
_926384
650 _aMTech Theses
_926385
650 _aDepartment of Mechanical Engineering
_926386
700 _aChakraborty, Prodyut Ranjan
_926387
942 _cTH
999 _c14740
_d14740