PSFVIP13 PSFVIP13

PLENARY / PROGRAM

Program

Timetable (tentative)


Plenary Lecture

Professor Jan A.Stasiek

Topic: Liquid crystal thermography as a modern and unique tool for technical and scientific research





The beginning of the 21st century is marked by the years of intensive research and development with micro- and nanotechnology, highly effective energy conversion technology and methods of reducing its impact on environmental degradation. Scientific researchers dealing with heat and mass transfer must face new challenges in the design and construction of modern and highly efficient processes, devices and apparatus. Designers of thermal devices expect, for example, more detailed information on the local values of the heat transfer coefficient, without limiting to its averaged values. These expectations are met by automated and fully computerized liquid crystal thermography (LCT) based on physico-chemical properties, among others: cholesterol esters (with a helicoids structure) as well as colour digital images processing. It allows not only to study complex geometries or the influence of inhomogeneous boundary conditions, but also pulsatile and turbulent flows of large scales and low frequencies. Phenomena characterized by such a complex heat transfer can be found in most devices where energy conversion processes take place. Furthermore, liquid crystal thermography (LCT) assisted by particle image velocimetry (PIV) and digital image processing (DIP) is an excellent and recognized measurement method used in the study of advanced thermal-flow processes and in major world-wide research centres. Theoretically, LCT enables the visualization of two-dimensional temperature and velocity fields with an accuracy of one pixel and identifying the influence of many thermo-physical and flow factors on the formation of a laminar and turbulent boundary layer. Therefore ,in the plenary lecture, the history of LCT techniques will be reviewed and the principal methods are described, using examples from current literature and own research.

Jan A.Stasiek
Professor, Gdansk University of Technology, Poland

Professor Han Seo Ko

Topic: Analysis of multi-phase and electrohydrodynamic (EHD) flow for convective heat transfer using visualization technique

The interaction between electrostatic and hydrodynamic phenomena was analyzed by adopting advanced techniques for numerical simulation and flow visualization. Rising bubbles inside a conductive medium can affect formation of electric field. The current varies depending on the occupation of non-conductive volume, and local electric signals can be interpreted as dispersed phase. Interesting influence between different physics can be applied to the study on a wire-mesh sensor (WMS) which is used to measure the characteristics of the multiphase flow. Electrohydrodynamic (EHD) flow is a promising field, especially for gas pumping applications. The EHD flow can be produced by the formation of non-thermal plasma (NTP) on a surface with high curvature. In this study, an analytical model was employed, and the experiment was carried out with the configuration of a wire and two cylinders in an open space. The Townsend relation between electric signals was checked for the stable generation of corona discharge, and the empirical equation was employed to verify the relation between parameters, such as current, voltage, and momentum. The cooling performance of the EHD flow was evaluated by comparison with the heat transfer coefficient of natural convection. The heat transfer coefficient and Nusselt number were calculated, and their correlation could be obtained.

Han Seo Ko
Professor, School of Mechanical Engineering,
Sungkyunkwan University, Korea

Professor Nobuyuki Oshima

Topic: Be Ambitious ! to use Open-source software for CFD and flow visualization

Recently, useful open-source software are published for CFD and related simulations. They are widely applied to varieties of physical and engineering problems, which are operated by difference scale computers, from notebook PC to supercomputer “FUGAKU”. As an entrance of “Open-source CFD”, a few results of major software as OpenFOAM, SU2, FrontFlow and their coupling software are introduced for the applications to bubble flow in turbulent boundary layer, flow-structure interaction of artery flow, and spray/combustion flow in gas-turbine, etc. These examples will make researchers, scientists and engineers “Be Ambitious !” to use Open-source CFD and flow visualization.
On the other hand, open-source CFD still has merits and demerits to develop, to distribute and to use, as compared to other ways by commercial software and/or unpublished special-maid ones, though the recent development of computers and networks brings much easier access to required data and information. Shall we discuss how to support such open-source world in CFD and visualization?

Nobuyuki Oshima
Professor, Division of Mechanical and Aerospace Engineering
Faculty of Engineering, Hokkaido university



Plenary Lecture

Professor Jan A.Stasiek
Gdansk University of Technology, Poland

Topic: Liquid crystal thermography as a modern and unique tool for technical and scientific research

The beginning of the 21st century is marked by the years of intensive research and development with micro- and nanotechnology, highly effective energy conversion technology and methods of reducing its impact on environmental degradation. Scientific researchers dealing with heat and mass transfer must face new challenges in the design and construction of modern and highly efficient processes, devices and apparatus. Designers of thermal devices expect, for example, more detailed information on the local values of the heat transfer coefficient, without limiting to its averaged values. These expectations are met by automated and fully computerized liquid crystal thermography (LCT) based on physico-chemical properties, among others: cholesterol esters (with a helicoids structure) as well as colour digital images processing. It allows not only to study complex geometries or the influence of inhomogeneous boundary conditions, but also pulsatile and turbulent flows of large scales and low frequencies. Phenomena characterized by such a complex heat transfer can be found in most devices where energy conversion processes take place. Furthermore, liquid crystal thermography (LCT) assisted by particle image velocimetry (PIV) and digital image processing (DIP) is an excellent and recognized measurement method used in the study of advanced thermal-flow processes and in major world-wide research centres. Theoretically, LCT enables the visualization of two-dimensional temperature and velocity fields with an accuracy of one pixel and identifying the influence of many thermo-physical and flow factors on the formation of a laminar and turbulent boundary layer. Therefore ,in the plenary lecture, the history of LCT techniques will be reviewed and the principal methods are described, using examples from current literature and own research.

Professor Han Seo Ko
School of Mechanical Engineering, Sungkyunkwan University, Korea

Topic: Analysis of multi-phase and electrohydrodynamic (EHD) flow for convective heat transfer using visualization technique

The interaction between electrostatic and hydrodynamic phenomena was analyzed by adopting advanced techniques for numerical simulation and flow visualization. Rising bubbles inside a conductive medium can affect formation of electric field. The current varies depending on the occupation of non-conductive volume, and local electric signals can be interpreted as dispersed phase. Interesting influence between different physics can be applied to the study on a wire-mesh sensor (WMS) which is used to measure the characteristics of the multiphase flow. Electrohydrodynamic (EHD) flow is a promising field, especially for gas pumping applications. The EHD flow can be produced by the formation of non-thermal plasma (NTP) on a surface with high curvature. In this study, an analytical model was employed, and the experiment was carried out with the configuration of a wire and two cylinders in an open space. The Townsend relation between electric signals was checked for the stable generation of corona discharge, and the empirical equation was employed to verify the relation between parameters, such as current, voltage, and momentum. The cooling performance of the EHD flow was evaluated by comparison with the heat transfer coefficient of natural convection. The heat transfer coefficient and Nusselt number were calculated, and their correlation could be obtained.

Professor Nobuyuki Oshima
Division of Mechanical and Aerospace Engineering, Faculty of Engineering, Hokkaido university

Topic: Be Ambitious ! to use Open-source software for CFD and flow visualization

Recently, useful open-source software are published for CFD and related simulations. They are widely applied to varieties of physical and engineering problems, which are operated by difference scale computers, from notebook PC to supercomputer “FUGAKU”. As an entrance of “Open-source CFD”, a few results of major software as OpenFOAM, SU2, FrontFlow and their coupling software are introduced for the applications to bubble flow in turbulent boundary layer, flow-structure interaction of artery flow, and spray/combustion flow in gas-turbine, etc. These examples will make researchers, scientists and engineers “Be Ambitious !” to use Open-source CFD and flow visualization.
On the other hand, open-source CFD still has merits and demerits to develop, to distribute and to use, as compared to other ways by commercial software and/or unpublished special-maid ones, though the recent development of computers and networks brings much easier access to required data and information. Shall we discuss how to support such open-source world in CFD and visualization?

















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