Nonlinear dynamics of heated falling films under the influence of long-range Van Der Walls intermolecular force interactions

Thin liquid film flowing on an inclined plane and subjected to various physico-chemical effects such as thermocapillarity, solutal-Marangoni and evaporative instabilities at the film surface and subjected to van der Waals intermolecular interaction forces, has been numerically simulated using explic...

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Main Authors: Jameel, Ahmad Tariq, Hamza, Mohammad Ameer, Asrar, Waqar
Format: Conference or Workshop Item
Language:English
Published: 2018
Subjects:
Online Access:http://irep.iium.edu.my/66896/
http://irep.iium.edu.my/66896/1/66896_NONLINEAR%20DYNAMICS%20-%20tentative.pdf
id iium-66896
recordtype eprints
spelling iium-668962018-10-25T01:59:22Z http://irep.iium.edu.my/66896/ Nonlinear dynamics of heated falling films under the influence of long-range Van Der Walls intermolecular force interactions Jameel, Ahmad Tariq Hamza, Mohammad Ameer Asrar, Waqar TJ Mechanical engineering and machinery Thin liquid film flowing on an inclined plane and subjected to various physico-chemical effects such as thermocapillarity, solutal-Marangoni and evaporative instabilities at the film surface and subjected to van der Waals intermolecular interaction forces, has been numerically simulated using explicit and implicit finite difference methods. There are several works published on flow of thin liquid films employing various flow configurations of thin film such as thin film on plane, inclined, and wavy surfaces over the past years. Thin film flow on inclined surface compared to on a horizontal surface, also experiences the gravity force which may play substantial role in the nonlinear dynamics of the film coupled with other forces. In this research, we attempt to update our previous study of the stability and dynamics of thin liquid films subjected to thermocapillary and evaporative instabilities at the free surface by including additional instabilities owing to long range van der Waals force in the film model. Similar to the previous studies cited in the literature (Joo et al., 1991; Hamza, 2017), for a Newtonian liquid, flow in thin liquid film on an inclined support and bounded by a passive gas, is represented by Navier-Stokes equation, equation of continuity and appropriate boundary conditions. The external effects are incorporated in the body force term of the Navier-Stokes equation. Following the procedure as outlined in the literature these governing equations are simplified followinga long-wave asymptotic analysis to derive a nonlinear fourth order partial differential equation, henceforth referred to as equation of evolution (EOE), which describes the temporal and spatial evolution of the interfacial instability in the film caused by complex nonlinear interactions of internal and/or external forces. We carried out extensive numerical simulations for various combinations of thin film flow parameters representative of different physical flow situations encountered in practice. Especially the effect of van der Waals forces on the film morphology and breakup is investigated at depth. This clearly shows that van der Walls forces though insignificant in thick films (proportional to h-6, where h is the film thickness) assumes significant role at short distances imparting catastrophic effect on the film instability as thin film approached breakup point. Here we present the results of our numerical simulation as an attempt to decipher the complex nonlinear dynamics of thin film flows especially delineating the role of van der Waals interaction forces in combination with other antagonistic physico-chemical effects. 2018 Conference or Workshop Item NonPeerReviewed application/pdf en http://irep.iium.edu.my/66896/1/66896_NONLINEAR%20DYNAMICS%20-%20tentative.pdf Jameel, Ahmad Tariq and Hamza, Mohammad Ameer and Asrar, Waqar (2018) Nonlinear dynamics of heated falling films under the influence of long-range Van Der Walls intermolecular force interactions. In: 4th International Conference on Mechanical, Automotive, and Aerospace Engineering 2018 (ICMAAE’18), 19th-20th September 2018, Kuala Lumpur. (Unpublished)
repository_type Digital Repository
institution_category Local University
institution International Islamic University Malaysia
building IIUM Repository
collection Online Access
language English
topic TJ Mechanical engineering and machinery
spellingShingle TJ Mechanical engineering and machinery
Jameel, Ahmad Tariq
Hamza, Mohammad Ameer
Asrar, Waqar
Nonlinear dynamics of heated falling films under the influence of long-range Van Der Walls intermolecular force interactions
description Thin liquid film flowing on an inclined plane and subjected to various physico-chemical effects such as thermocapillarity, solutal-Marangoni and evaporative instabilities at the film surface and subjected to van der Waals intermolecular interaction forces, has been numerically simulated using explicit and implicit finite difference methods. There are several works published on flow of thin liquid films employing various flow configurations of thin film such as thin film on plane, inclined, and wavy surfaces over the past years. Thin film flow on inclined surface compared to on a horizontal surface, also experiences the gravity force which may play substantial role in the nonlinear dynamics of the film coupled with other forces. In this research, we attempt to update our previous study of the stability and dynamics of thin liquid films subjected to thermocapillary and evaporative instabilities at the free surface by including additional instabilities owing to long range van der Waals force in the film model. Similar to the previous studies cited in the literature (Joo et al., 1991; Hamza, 2017), for a Newtonian liquid, flow in thin liquid film on an inclined support and bounded by a passive gas, is represented by Navier-Stokes equation, equation of continuity and appropriate boundary conditions. The external effects are incorporated in the body force term of the Navier-Stokes equation. Following the procedure as outlined in the literature these governing equations are simplified followinga long-wave asymptotic analysis to derive a nonlinear fourth order partial differential equation, henceforth referred to as equation of evolution (EOE), which describes the temporal and spatial evolution of the interfacial instability in the film caused by complex nonlinear interactions of internal and/or external forces. We carried out extensive numerical simulations for various combinations of thin film flow parameters representative of different physical flow situations encountered in practice. Especially the effect of van der Waals forces on the film morphology and breakup is investigated at depth. This clearly shows that van der Walls forces though insignificant in thick films (proportional to h-6, where h is the film thickness) assumes significant role at short distances imparting catastrophic effect on the film instability as thin film approached breakup point. Here we present the results of our numerical simulation as an attempt to decipher the complex nonlinear dynamics of thin film flows especially delineating the role of van der Waals interaction forces in combination with other antagonistic physico-chemical effects.
format Conference or Workshop Item
author Jameel, Ahmad Tariq
Hamza, Mohammad Ameer
Asrar, Waqar
author_facet Jameel, Ahmad Tariq
Hamza, Mohammad Ameer
Asrar, Waqar
author_sort Jameel, Ahmad Tariq
title Nonlinear dynamics of heated falling films under the influence of long-range Van Der Walls intermolecular force interactions
title_short Nonlinear dynamics of heated falling films under the influence of long-range Van Der Walls intermolecular force interactions
title_full Nonlinear dynamics of heated falling films under the influence of long-range Van Der Walls intermolecular force interactions
title_fullStr Nonlinear dynamics of heated falling films under the influence of long-range Van Der Walls intermolecular force interactions
title_full_unstemmed Nonlinear dynamics of heated falling films under the influence of long-range Van Der Walls intermolecular force interactions
title_sort nonlinear dynamics of heated falling films under the influence of long-range van der walls intermolecular force interactions
publishDate 2018
url http://irep.iium.edu.my/66896/
http://irep.iium.edu.my/66896/1/66896_NONLINEAR%20DYNAMICS%20-%20tentative.pdf
first_indexed 2023-09-18T21:34:59Z
last_indexed 2023-09-18T21:34:59Z
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