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Articles 961 - 990 of 1206

Full-Text Articles in Chemical Engineering

Thermocapillary Effects In Driven Dewetting And Self-Assembly Of Pulsed Laser-Irradiated Metallic Films, Agegnehu Atena, Mikhail Khenner Jan 2009

Thermocapillary Effects In Driven Dewetting And Self-Assembly Of Pulsed Laser-Irradiated Metallic Films, Agegnehu Atena, Mikhail Khenner

Mathematics Faculty Publications

In this paper the lubrication-type dynamical model is developed of a molten, pulsed laser-irradiated metallic film. The heat transfer problem that incorporates the absorbed heat from a single beam or interfering beams is solved analytically. Using this temperature field, we derive the 3D long-wave evolution PDE for the film height. To get insights into dynamics of dewetting, we study the 2D version of the evolution equation by means of a linear stability analysis and by numerical simulations. The stabilizing and destabilizing effects of various system parameters, such as the peak laser beam intensity, the film optical thickness, the Biot and …


Thermocapillary Effects In Driven Dewetting And Self-Assembly Of Pulsed Laser-Irradiated Metallic Films, Agegnehu Atena, Mikhail Khenner Jan 2009

Thermocapillary Effects In Driven Dewetting And Self-Assembly Of Pulsed Laser-Irradiated Metallic Films, Agegnehu Atena, Mikhail Khenner

Mathematics Faculty Publications

In this paper the lubrication-type dynamical model is developed of a molten, pulsed laser-irradiated metallic film. The heat transfer problem that incorporates the absorbed heat from a single beam or interfering beams is solved analytically. Using this temperature field, we derive the 3D long-wave evolution PDE for the film height. To get insights into dynamics of dewetting, we study the 2D version of the evolution equation by means of a linear stability analysis and by numerical simulations. The stabilizing and destabilizing effects of various system parameters, such as the peak laser beam intensity, the film optical thickness, the Biot and …


Systems Chemistry And Parrondo’S Paradox: Computational Models Of Thermal Cycling, Daniel C. Osipovitch, Carl Barratt, Pauline M. Schwartz Jan 2009

Systems Chemistry And Parrondo’S Paradox: Computational Models Of Thermal Cycling, Daniel C. Osipovitch, Carl Barratt, Pauline M. Schwartz

Chemistry and Chemical Engineering Faculty Publications

A mathematical concept known as Parrondo’s paradox motivated the development of several novel computational models of chemical systems in which thermal cycling was explored. In these kinetics systems we compared the rates of formation of product under cycling temperature and steady-sate conditions. We found that a greater concentration of product was predicted under oscillating temperature conditions. Our computational models of thermal cycling suggest new applications in chemical and chemical engineering systems.


Inhomogeneous Degradation Of Polymer Electrolyte Membrane In Pem Fuel Cells, Xinyu Huang, Wonseok Yoon Jan 2009

Inhomogeneous Degradation Of Polymer Electrolyte Membrane In Pem Fuel Cells, Xinyu Huang, Wonseok Yoon

Faculty Publications

Membrane durability is one of the technical barriers for the commercialization of polymer electrolyte membrane (PEM) fuel cells. Membrane embrittlement (a form of mechanical weakening) can lead to the frequently observed “sudden death” behavior of PEM fuel cells. It is the objective of this study to explore the fundamental mechanisms of the mechanical weakening of perfluorosulfonic acid (PFSA) based electrolyte membranes during the accelerated degradation test.


Simulation Of A Tubular Solid Oxide Fuel Cell Stack Operating On Biomass Syn-Gas Using Aspen Plus, Wayne Doherty, Anthony Reynolds, David Kennedy Jan 2009

Simulation Of A Tubular Solid Oxide Fuel Cell Stack Operating On Biomass Syn-Gas Using Aspen Plus, Wayne Doherty, Anthony Reynolds, David Kennedy

Articles

A tubular solid oxide fuel cell (SOFC) stack is modelled and its operation on biomass syn-gas is investigated. The objective of this work is to develop a computer simulation model of a biomass gasification-SOFC (BG-SOFC) system capable of predicting performance under various operating conditions and using diverse fuels. The stack is modelled using Aspen Plus and considers ohmic, activation and concentration losses. It is validated against published data for operation on natural gas. Operating parameters such as fuel and air utilisation factor (Uf and Ua), current density (j) and steam to carbon ratio ( …


Modelling And Simulation Of A Biomass Gasification-Solid Oxide Fuel Cell Combined Heat And Power Plant Using Aspen Plus, Wayne Doherty, Anthony Reynolds, David Kennedy Jan 2009

Modelling And Simulation Of A Biomass Gasification-Solid Oxide Fuel Cell Combined Heat And Power Plant Using Aspen Plus, Wayne Doherty, Anthony Reynolds, David Kennedy

Conference Papers

In this paper the operation and performance of a high temperature solid oxide fuel cell (SOFC) stack on biomass syn-gas from a demonstration biomass gasification combined heat and power (CHP) plant is investigated. The objective of this work is to develop a computer simulation model of a biomass-SOFC CHP system, flexible enough for use in industry, capable of predicting system performance under various operating conditions and using diverse fuels. The biomass gasifier is of the dual fluidised bed (DFB) type with steam as the gasifying agent and is operated at atmospheric pressure. The tubular SOFC configuration, developed by Siemens Power …


Micromechanics Model Based On The Nanostructure Of Pfsa Membranes, Ahmet Kusoglu, Michael H. Santare, Anette M. Karlsson, William B. Johnson, Simon Cleghorn Nov 2008

Micromechanics Model Based On The Nanostructure Of Pfsa Membranes, Ahmet Kusoglu, Michael H. Santare, Anette M. Karlsson, William B. Johnson, Simon Cleghorn

Mechanical Engineering Faculty Publications

A micromechanics model is developed to predict Young’s modulus of perfluorosulfonic acid (PFSA) membranes at various temperatures and water contents. The morphology of PFSA membranes is characterized by a two-phase structure, where hydrophilic clusters expand to hold water molecules during swelling, whereas the hydrophobic polymer network maintains the structural stability. A representative volume element (RVE) is proposed based on the descriptions for the nanostructure of PFSA membranes available in the literature. On the basis of mechanics model, we estimate Young’s modulus in tension of PFSA membranes as a function of water volume fraction for various temperatures. The results show that …


Isolation Of Methyl Laurate From Coconut Oil As Raw Material For Fatty Alcohol Sulfate, Rita Arbianti, Tania Surya Utami, Astri Nugroho Nov 2008

Isolation Of Methyl Laurate From Coconut Oil As Raw Material For Fatty Alcohol Sulfate, Rita Arbianti, Tania Surya Utami, Astri Nugroho

Makara Journal of Technology

Isolation of Methyl Laurate from Coconut Oil as Raw Material for Fatty Alcohol Sulfate. Methyl laurate is a raw or base material for many industries, including surfactant industries. In this research, coconut oil (VCO) is transesterified with methanol to produce methyl ester, using NaOH as the catalyst. Methyl laurate is then separated by method based on the difference in melting point. This research focuses at determining the effects of some variables in transesterification on the concentration of produced methyl laurate. The variables are temperature (40 oC, 50 oC, 60 oC, 80 oC), time of transesterification reaction (0,5 hour, 1 hour, …


The Decompositioning Of Volatile-Matter Of Tanjung Enim Coal By Using Thermogravimetry Analyzer (Tga), Nukman Nukman Nov 2008

The Decompositioning Of Volatile-Matter Of Tanjung Enim Coal By Using Thermogravimetry Analyzer (Tga), Nukman Nukman

Makara Journal of Technology

The Decompositioning of Volatile-Matter of Tanjung Enim Coal by using Thermogravimetry Analyzer (TGA). Coal is a nature material which a kind of energy source. The decompotition of coal could analyze by heat treated using thermogravimetry analyzer. The decomposition of the volatile matter for three kinds of Tanjung Enim coal could be known. The value of activation energy that be found diference, then for Semi Anthracite, Bitumonius and Sub Bituminous Coal, the initial temperatures are 60.8 oC, 70.7 oC, 97.8oC, and the last temperatures are 893.8 oC, 832 oC, 584.6oC.


Phase Unwrapping Insar Image Using Local Energy Minimization Approach, Kusworo Adi, Tati L.R. Mengko, Andriyan B. Suksmono, Hendra Gunawan Nov 2008

Phase Unwrapping Insar Image Using Local Energy Minimization Approach, Kusworo Adi, Tati L.R. Mengko, Andriyan B. Suksmono, Hendra Gunawan

Makara Journal of Technology

Phase Unwrapping InSAR Image Using Local Energy Minimization Approach. Reconstruction process of phase data from its cover is called Phase Unwrapping (PU). Ideally, without any noise phrase, singularity, and aliasing problems, the phase information can be unwrapped easily. However, in fact, the phase data actually always get noise disturbance and discontinuity. The PU process becomes more complicated and needs a better PU algorithm to address the problems properly. In this research, the local PU algorithm is developed using minimization of close related firstorder pixels energy approach. In this method, the energy difference between four close related pixels is counted, followed …


Two Element Microstrip Antenna Array With Defected Ground Structure, Fitri Yuli Zulkifli, Eko Tjipto Rahardjo, Muhamad Asvial, Djoko Hartanto Nov 2008

Two Element Microstrip Antenna Array With Defected Ground Structure, Fitri Yuli Zulkifli, Eko Tjipto Rahardjo, Muhamad Asvial, Djoko Hartanto

Makara Journal of Technology

Two Element Microstrip Antenna Array with Defected Ground Structure. This paper presents a two element microstrip antenna array using trapezium shape defected ground structure (DGS). The DGS is inserted in the ground plane between two elements of antenna array. Insertion of the DGS is intended to suppress the mutual coupling effect produced by antenna array. Simulation and measurement results were taken and compared between antenna array with and without DGS. Measurement results show that the antenna with DGS compared to antenna without DGS can suppress mutual coupling effect to 7.9 dB, improve the return loss to 33.29% from -30.188 dB …


Hydrogen Absorption In Weldments Of Overlaid Claded Pressure Vessel, Ronnie Higuchi Rusli Nov 2008

Hydrogen Absorption In Weldments Of Overlaid Claded Pressure Vessel, Ronnie Higuchi Rusli

Makara Journal of Technology

Cracks was found in type 347 stainless steel internal attachment welds of a reactor for a high temperature, and high pressure hydrogen service. One of the possible causes of cracking is low cycle fatigue cracking induced by repetition of thermal stress to embrittled weld metal. Type 347 weld metal loses its ductility by presence of sigma phase and hydrogen.


Neutron Irradiation On Ss316 Material For Radioactive Endovascular Stent Production, Rohadi Awaludin, Abidin Abidin, Sriyono Sriyono Nov 2008

Neutron Irradiation On Ss316 Material For Radioactive Endovascular Stent Production, Rohadi Awaludin, Abidin Abidin, Sriyono Sriyono

Makara Journal of Technology

Neutron Irradiation on SS316 Material for Radioactive Endovascular Stent Production. It was reported that restenosis could be prevented by radioactive endovascular stent. SS316 material of endovascular stent has been irradiated at pneumatic rabbit system of G.A. Siwabessy reactor for 5 minutes for producing radioactive stent by neutron activation. After 10 days of decay, the irradiated SS316 was measured by gamma spectrometer. The radioisotopes of 51Cr, 59Fe and 60Co were detected in the irradiated SS316 with radioactivity of 5990, 107 and 109 Bq/mg respectively. The Calculation results showed that radioisotopes of 51Cr, 59Fe and 55Fe were produced by neutron activation. The …


Physical Characteristics And Utilization Oft The Karst Beaches In Kabupaten Gunungkidul, Astrid Damayanti, Ranum Ayuningtyas Nov 2008

Physical Characteristics And Utilization Oft The Karst Beaches In Kabupaten Gunungkidul, Astrid Damayanti, Ranum Ayuningtyas

Makara Journal of Technology

Physical Characteristics and Utilization oft the Karst Beaches in Kabupaten Gunungkidul. Karsts beaches at Gunungkidul Regency (Baron, Kukup, Sepanjang, Drini, Krakal, Ngandong, and Sundak), located in south of Daerah Istimewa Yogyakarta Province, have economic potential. Even they have similarity in geological condition (genesis and morphological processes), but they have different physical characteristics. Based on result of observation environment on morphological conditions and spatial analysis method, we found the proper utilization of the beaches.


Spectral Response Surfaces And The Ringing Response Of Offshore Structures, I Ketut Suastika Nov 2008

Spectral Response Surfaces And The Ringing Response Of Offshore Structures, I Ketut Suastika

Makara Journal of Technology

A method, called spectral response surface method, is proposed for the study of the ringing phenomenon of offshore structures. Newman’s results for diffraction force on a column were reformulated in terms of the frequency components of the ocean surface and their Hilbert transforms. Using a first-order reliability method together with a dynamic model for the structural response, it is straightforward to calculate the ocean surface history most likely to generate an extreme ringing response and the ringing response history.


How Accurate Is Students’ Self Assessment Of Computer Skills?, Michael A. Collura, Samuel Bogan Daniels Jun 2008

How Accurate Is Students’ Self Assessment Of Computer Skills?, Michael A. Collura, Samuel Bogan Daniels

Engineering and Applied Science Education Faculty Publications

Self-evaluation by students is commonly used as a key element in program and course assessment plans. Such instruments are intended to provide crucial feedback for program improvement and thus play a significant role in closing our assessment loop. For many of the program outcomes, self-assessment by current students and graduates augments other, more objective measures. However, for some outcomes there are no practical means of obtaining objective assessment and we must rely on self-assessment. The heavy reliance on this metric begs the question “How accurate is student self-assessment?” This paper provides data from a second-semester engineering course in which students …


Modeling Of Thermodynamically Coupled Reaction-Transport Systems, Yaşar Demirel May 2008

Modeling Of Thermodynamically Coupled Reaction-Transport Systems, Yaşar Demirel

Yaşar Demirel Publications

Nonisothermal reaction-diffusion systems control the behavior of many transport and rate processes in physical, chemical and biological systems, such as pattern formation and chemical pumps. Considerable work has been published on mathematically coupled nonlinear differential equations by neglecting thermodynamic coupling between a chemical reaction and transport processes of mass and heat. This study presents the modeling of thermodynamically coupled system of a simple elementary chemical reaction with molecular heat and mass transport. The thermodynamic coupling refers that a flow occurs without or against its primary thermodynamic driving force, which may be a gradient of temperature or chemical potential or reaction …


The Development Of Inverter Fuzzy Logic Control For Induction Motor Control By Vector Control Method In Electric Vehicle, Era Purwanto, Mohammad Ashary, Subagio Subagio, Mauridhi Heri Purnomo Apr 2008

The Development Of Inverter Fuzzy Logic Control For Induction Motor Control By Vector Control Method In Electric Vehicle, Era Purwanto, Mohammad Ashary, Subagio Subagio, Mauridhi Heri Purnomo

Makara Journal of Technology

The development of Inverter Fuzzy Logic Control for Induction Motor Control by Vector Control Method in Electric Vehicle. In response to concerns about energy cost, energy dependence, and environmental damage, a rekindling of interest in electric vehicles (EV’s) has been obvious. Thus, the development of power electronics technology for EV’s will take an accelerated pace to fulfill the market needs, regarding with the problem in this paper is presented development of fuzzy logic inverter in induction motor control for electric vehicle propulsion. The Fuzzy logic inverter is developed in this system to directed toward developing an improved propulsion system for …


Internet Congestion Control System, Pranoto Hidaya Rusmin, Carmadi Machbub, Agung Harsoyo, Hendrawan Hendrawan Apr 2008

Internet Congestion Control System, Pranoto Hidaya Rusmin, Carmadi Machbub, Agung Harsoyo, Hendrawan Hendrawan

Makara Journal of Technology

Internet Congestion Control System. Internet congestion occurs when resource demands exceeds the network capacity. But, it is not the only reason. Congestion can happen on some users because some others user has higher sending rate. Then some users with lower sending rate will experience congestion. This partial congestion is caused by inexactly feedback. At this moment congestion are solved by the involvement of two controlling mechanisms. These mechanisms are flow/congestion control in the TCP source and Active Queue Management (AQM) in the router. AQM will provide feedback to the source a kind of indication for the occurrence of the congestion …


A Study Of Co2 Absorption Using Jet Bubble Column, Setiadi Setiadi, Nita Tania Hadiyani, Hantizen Hantizen, Dijan Supramono Apr 2008

A Study Of Co2 Absorption Using Jet Bubble Column, Setiadi Setiadi, Nita Tania Hadiyani, Hantizen Hantizen, Dijan Supramono

Makara Journal of Technology

A Study of CO2 Absorption Using Jet Bubble Column. The phenomenon of plunging jet gas-liquid contact occurs quite often in nature, it's momentum carries small air bubbles with it into the reactor medium. The momentum of the liquid stream can be sufficient to carry small bubbles completely to the bottom of the vessel. A stream of liquid falling toward a level surface of that liquid will pull the surrounding air along with it. It will indent the surface of the liquid to form a trumpet-like shape. If the velocity of the stream is high enough, air bubbles will be pulled …


The Role Of 1 And 9 Wt.% Zn In Precipitation Hardening Of Aa319 Aluminium, Bondan Tiara Sofyan, Sari Susanti, Ridwan R. Yusfranto Apr 2008

The Role Of 1 And 9 Wt.% Zn In Precipitation Hardening Of Aa319 Aluminium, Bondan Tiara Sofyan, Sari Susanti, Ridwan R. Yusfranto

Makara Journal of Technology

The Role of 1 and 9 wt.% Zn in Precipitation Hardening of AA319 Aluminium. Aluminium alloys are widely used for automotive application due to its low density and high corrosion resistance. For economic reason, casting of automotive products always uses aluminium scrap as charging materials that may result in fluctuation of content of alloying element, such as Zn. This research studies the role of Zn in precipitation hardening of AA319 aluminium alloys. Hardness and tensile testing were conducted to study the mechanical properties of the alloys, while ageing response was followed by hardness measurements. Evolution of microstructures was observed by …


Biomass Production Chlorella Vulgaris Buitenzorg Using Series Of Bubble Column Photo Bioreactor With A Periodic Illumination, Anondho Wijanarko, Dianursanti Dianursanti, Muryanto Muryanto, Josia Simanjuntak, Praswasti Pembangun Dyah Kencana Wulan, Heri Hermansyah, Misri Gozan, Roekmijati Widaningroem Soemantojo Apr 2008

Biomass Production Chlorella Vulgaris Buitenzorg Using Series Of Bubble Column Photo Bioreactor With A Periodic Illumination, Anondho Wijanarko, Dianursanti Dianursanti, Muryanto Muryanto, Josia Simanjuntak, Praswasti Pembangun Dyah Kencana Wulan, Heri Hermansyah, Misri Gozan, Roekmijati Widaningroem Soemantojo

Makara Journal of Technology

Chlorella vulgaris Buitenzorg cultivation using three bubble column photo bioreactors arranged in series with a volume of 200 mL for 130 hours shows an increase of biomass production of Chlorella vulgaris Buitenzorg up to 1.20 times and a decrease of the ability of CO2 fixation compared to single reactor at a periodic sun illumination cycle. The operation conditions on cultivation are as following: T, 29.0oC; P,1 atm.; UG, 2.40 m/h; CO2, 10%; Benneck medium; and illumination source by Phillip Halogen Lamp 20W /12V/ 50Hz. Other research parameters such as microbial carbon dioxide transferred rate (qco2), CO2 transferred rate (CTR), energy …


Ad Hoc On-Demand Distance Vector (Aodv) Routing Protocol Performance Evaluation On Hybrid Ad Hoc Network: Comparison Of Result Of Ns-2 Simulation And Implementation On Testbed Using Pda, Riri Fitri Sari, Abdusy Syarif, Bagio Budiardjo Apr 2008

Ad Hoc On-Demand Distance Vector (Aodv) Routing Protocol Performance Evaluation On Hybrid Ad Hoc Network: Comparison Of Result Of Ns-2 Simulation And Implementation On Testbed Using Pda, Riri Fitri Sari, Abdusy Syarif, Bagio Budiardjo

Makara Journal of Technology

Ad Hoc on-Demand Distance Vector (AODV) Routing Protocol Performance Evaluation on Hybrid Ad Hoc Network: Comparison of Result of Ns-2 Simulation and Implementation on Testbed using PDA. In Mobile Ad hoc NETwork (MANET), node supplemented with wireless equipment has the capacity to manage and organise autonomously, without the presence of network infrastructures. Hybrid ad hoc network, enable several nodes to move freely (mobile) to create instant communication. Independent from infrastructure. They could access the Local Area Network (LAN) or the Internet. Functionalities of ad hoc network very much dependent on the routing protocol that determines the routing around node. Ad …


Substrates Preparation From Woody Tropical Waste Biomass For Biohydrogen Production, Dwi Susilaningsih, Theresia Umi Harwati, Khairul Anam, Yopi Yopi Apr 2008

Substrates Preparation From Woody Tropical Waste Biomass For Biohydrogen Production, Dwi Susilaningsih, Theresia Umi Harwati, Khairul Anam, Yopi Yopi

Makara Journal of Technology

Substrates Preparation from Woody Tropical Waste Biomass for Biohydrogen Production. Addressing to the global warming problem, energy crisis and pollution, hydrogen production by micro-organisms using biotechnological approach should be considered, since it fulfils the recent society requirement to safely produce, renewable and environmental friendly energy. Hydrogen is one of the most promising green energy sources, because it is easily converted to electricity and cleanly combustible. There are three types of micro-organisms for hydrogen production, the first is cyanobacteria through the photosynthesis process, the second is anaerobic bacteria, which use organic substances as electron donor and energy and convert them to …


The Effect Of Ozone And Zeolite Concentration To The Performance Of The Treatment Of Wastewater Containing Heavy Metal Using Flotation Process, Eva Fathul Karamah, Setijo Bismo, Hotdi M. Simbolon Apr 2008

The Effect Of Ozone And Zeolite Concentration To The Performance Of The Treatment Of Wastewater Containing Heavy Metal Using Flotation Process, Eva Fathul Karamah, Setijo Bismo, Hotdi M. Simbolon

Makara Journal of Technology

The Effect of Ozone and Zeolite Concentration to the Performance of the Treatment of Wastewater Containing Heavy Metal Using Flotation Process. Industrial wastewater which contains heavy metal cannot be disposed to the environment directly, due to its toxicity. In this research, separation of metal from wastewater was conducted by sorptive flotation method, using Lampung natural zeolite as bonding agent. The most common diffuser used in the flotation process is air or oxygen. In this research, ozone is used as diffuser because it is a stronger oxidant and more dissolvable in water than oxygen. Besides, ozone is a coagulant aid and …


Building Fire Safety Audit At Faculty X, University Of Indonesia, Year 2006, Fatma Lestari, Rm. Yodan Amaral Panindrus Apr 2008

Building Fire Safety Audit At Faculty X, University Of Indonesia, Year 2006, Fatma Lestari, Rm. Yodan Amaral Panindrus

Makara Journal of Technology

Building Fire Safety Audit at Faculty X, University of Indonesia, Year 2006. Fire may cause loss of life, material and valuable assets. The objective of this study is to conduct audit for fire safety and emergency response in the building at Faculty X, University of Indonesia, Depok. The audit results on the building fire safety facilities including emergency response and preparedness are then compared to the Building Code Australia (BCA) and Indonesian regulation on the building fire safety (Kep.MenPU.No 10 and 11/KPTS/2000). The building selected are Building A, B, C, D, F and G. Building classification for A, B, D, …


Morphologies And Kinetics Of A Dewetting Ultrathin Solid Film, Mikhail Khenner Jan 2008

Morphologies And Kinetics Of A Dewetting Ultrathin Solid Film, Mikhail Khenner

Mathematics Faculty Publications

The surface evolution model based on geometric partial differential equation is used to numerically study the kinetics of dewetting and dynamic morphologies for the localized pinhole defect in the surface of the ultrathin solid film with the strongly anisotropic surface energy. Depending on parameters such as the initial depth and width of the pinole, the strength of the attractive substrate potential and the strength of the surface energy anisotropy, the pinhole may either extend to the substrate and thus rupture the film, or evolve to the quasiequilibrium shape while the rest of the film surface undergoes phase separation into a …


Enhanced Stability Of A Dewetting Thin Liquid Film In A Single-Frequency Vibration Field, Mikhail Khenner Jan 2008

Enhanced Stability Of A Dewetting Thin Liquid Film In A Single-Frequency Vibration Field, Mikhail Khenner

Mathematics Faculty Publications

Dynamics of a thin dewetting liquid film on a vertically oscillating substrate is considered. We assume moderate vibration frequency and large (compared to the mean film thickness) vibration amplitude. Using the lubrication approximation and the averaging method, we formulate the coupled sets of equations governing the pulsatile and the averaged fluid flows in the film, and then derive the nonlinear amplitude equation for the averaged film thickness. We show that there exists a window in the frequency-amplitude domain where the parametric and shear-flow instabilities of the pulsatile flow do not emerge. As a consequence, in this window the averaged description …


Enhanced Stability Of A Dewetting Thin Liquid Film In A Single-Frequency Vibration Field, Sergey Shklyaev, Mikhail Khenner, Alexei Alabuzhev Jan 2008

Enhanced Stability Of A Dewetting Thin Liquid Film In A Single-Frequency Vibration Field, Sergey Shklyaev, Mikhail Khenner, Alexei Alabuzhev

Mathematics Faculty Publications

Dynamics of a thin dewetting liquid film on a vertically oscillating substrate is considered. We assume moderate vibration frequency and large (compared to the mean film thickness) vibration amplitude. Using the lubrication approximation and the averaging method, we formulate the coupled sets of equations governing the pulsatile and the averaged fluid flows in the film, and then derive the nonlinear amplitude equation for the averaged film thickness. We show that there exists a window in the frequency-amplitude domain where the parametric and shear-flow instabilities of the pulsatile flow do not emerge. As a consequence, in this window the averaged description …


Enhanced Stability Of A Dewetting Thin Liquid Film In A Single-Frequency Vibration Field, Sergey Shklyaev, Mikhail Khenner, Alexei Alabuzhev Jan 2008

Enhanced Stability Of A Dewetting Thin Liquid Film In A Single-Frequency Vibration Field, Sergey Shklyaev, Mikhail Khenner, Alexei Alabuzhev

Mathematics Faculty Publications

Dynamics of a thin dewetting liquid film on a vertically oscillating substrate is considered. We assume moderate vibration frequency and large (compared to the mean film thickness) vibration amplitude. Using the lubrication approximation and the averaging method, we formulate the coupled sets of equations governing the pulsatile and the averaged fluid flows in the film, and then derive the nonlinear amplitude equation for the averaged film thickness. We show that there exists a window in the frequency-amplitude domain where the parametric and shear-flow instabilities of the pulsatile flow do not emerge. As a consequence, in this window the averaged description …