The present work describes a numerical procedure to simulate the development of hydrodynamic entry region in a gravity-driven laminar liquid film flow over an inclined plane. It provides a better insight into the physics of developing film in entry region. A novel numerical approach is proposed which has the potential to provide solutions for the complex physics of liquid film spreading on solid walls. The method employs an incompressible flow algorithm to solve the governing equations, a PLIC-VOF method to capture the free surface evolution and a continuum surface force (CSF) model to include the effect of surface tension. To account for the moving contact line on the solid substrate, a precursor film model based wall treatment is implemented. Liquid film flow has been simulated for the Reynolds number range of 5 ≤ Re ≤ 37.5, and the predicted results are found to agree well with the available analytical and experimental data. © 2009 Taylor & Francis.

T Sundararajan

Department of Mechanical Engineering

Sarit Kumar Das

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Development of a PLIC-VOF method for the dynamic simulation of entry region flow in a laminar falling film

International Journal of Computational Fluid Dynamics

A finite-volume-based incompressible flow algorithm on Cartesian grid is presented for the simulation of evaporation phenomena in a falling liquid film under low wall superheat conditions. The model employs the PLIC-VOF method to capture the free surface evolution, and the continuum surface force (CSF) approximation to emulate the effects of interfacial tension. The phase change process is represented through a source term in the interfacial cells, which is evaluated from the normal temperature gradients on either side of the interface. In order to evaluate these discontinuous temperature gradients across the interface accurately, a simple and efficient ghost fluid method has been implemented, which properly takes into account the dynamic evolution of the interface. The overall numerical model, including the phase change algorithm, has been validated against standard benchmark analytical results. Finally, the model is used to simulate the evaporating flow of a 2-D laminar, developing film falling over an inclined plane surface, subjected to constant wall heat flux. The results thus obtained, clearly illustrate the significance of inertial effects in the developing region of the falling film, which are generally neglected in the available analytical models. It is also observed, that the evaporation of fluid commences only after the growing thermal boundary layer reaches the interface, and the length of the nonevaporating section reduces with the increase in wall heat flux value. Copyright © Taylor & Francis Group, LLC.

Numerical Heat Transfer; Part A: Applications

Numerical investigation of evaporation in the developing region of laminar falling film flow under constant wall heat flux conditions

The paper presents an analytical study which describes the laminar accelerating flow of a thin film along an inclined wall. When interfacial shear is taken into consideration it is found that the non-dimensional film thickness depends on two parameters (Fr/Re) and ρu-ratio, the effect of the latter being more pronounced for larger values of the former. The results are compared with those of earlier workers. © 1973.

Chemical Engineering Science

Accelerating laminar liquid film along an inclined wall

Numerical Heat Transfer and Fluid Flow

Heat Conduction

Transient simulations of cavitating flows using a modified volume-of-fluid (VOF) technique

An improved three-dimensional model for interface pressure calculations in free-surface flows

Transport Phenomena in Multiphase Systems

INTRODUCTION TO TRANSPORT PHENOMENA

Journal	International Journal of Computational Fluid Dynamics
ISSN	10618562
Open Access	No