As an engineer who has devoted himself in the nuclear industry for almost three decades, the author gave a personal view on educating two-phase flow and developing human resources. An expected role of universities in on-going discussions of collaboration among industry-government-academia is introduced. Reformation of two-phase flow education is discussed from two extreme viewpoints, the basic structure of physics and the practical system analysis.

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The Division of Energy and Environmental Systems in Hokkaido University is chasing energy systems contributing to sustain the global environment, such as next-generation nuclear reactor systems, nuclear safety, nuclear fuel cycles, nuclear wastes management, hydrogen fuel cells, advanced engine systems, and fluid energy systems. In these technologies, there exists common science and technology field, that is to say the multiphase flow. The filed of energy and environmental systems are very important not only for human beings but also for all the life on this planet, the Erath. Education and study of nuclear and energy engineering in this division has proved to be quite attractive for students and researchers on the view point of multiphase flow.

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Engineering design skills are some of the important competencies of an engineer. A standard for teaching engineering design skills has already been published by ABET in its “Engineering Design Criteria 2000”. In Japan, JABEE has strongly emphasized the need for an engineering design education program, mainly as a result of joining the Washington Accord as a signatory. At the same time, ASCE has announced “The Vision for Civil Engineering in 2025” and summarized the skills that future civil engineers should possess in the BOK2 (Body of Knowledge 2). In the BOK2, engineering design is treated as a critical skill that engineers who develop and maintain a sustainable infrastructure for the society must acquire. In this paper, we consider the nature of “civil engineering design education” in the context of tertiary education and make remarks on the planning and experimental implementation of an actual education program.

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The activities of Tohoku University Global COE Program “World Center of Education and Research for Trans-disciplinary Flow Dynamics”, particularly, the comprehensive and unique methodology to educate Doctoral Course students to acquire crucial leadership for handling multi-national academic and technology projects, are discussed.

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This document presents the background to human resource developments in science based technology, current state and policy developments. After defining general range statements that allow the competencies of the different categories to be distinguished, the paper presents the graduate attributes and professional competency profiles for three professional tracks: engineer, engineering technologist and engineering technician.

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We review the recent progress and successful applications of lattice Boltzmann method (LBM) to computational fluid dynamics. To clarify the important issue in the LBM simulation, this report shows the recent progress in the LBM, and summarizes both the advantages and disadvantages of the LBM. We also discuss the immersed boundary-lattice Boltzmann method (IB-LBM) that has received much attention in recent years. Due to the common feature of using the Cartesian mesh, the IB-LBM successfully calculates the rigid particle motions in a viscous fluid. We present one of key issues in the IB-LBM, and examine the applicability of the Immersed Boundary Method to the lattice kinetic scheme (LKS) for particulate flow.

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In industrial applications involving two-phase flows, the phase boundary information can be helpful in the design, control and safety of the flow process. Electrical impedance tomography (EIT) which has been hallmark in process tomography applications can be used to monitor these two-phase flows. This paper reviews various techniques for the estimation of phase boundary in two-phase flows using EIT.

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To examine the effects of fluid properties on countercurrent flow limitation (CCFL) in a hot leg of a pressurized water reactor (PWR), experiments are conducted using glycerol-water solutions and a 1/5 scale hot leg model with a rectangular channel. Numerical simulations are also carried out using a VOF (volume of fluid) method implemented in the CFD software, FLUENT 6.3.26. The increase in the liquid viscosity does not change the intercept coefficient C in the Wallis-type CCFL correlation but increases the proportional coefficient m, which indicates that the liquid viscosity does not affect the interfacial drag but influences the wall friction. CCFL predicted for steam-water flow at 5 MPa, corresponding to a high gas density and low liquid viscosity condition, is greatly mitigated, which indicates that the gas density has a significant effect on the interfacial drag.

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Cleaning effects of micro-bubbles were experimentally investigated. Pipe flows with and without the micro-bubbles were used for the study of the cleaning effects. The lard oil was used as a stain sample which was painted on the inner surface of the pipe. Removal rate of the lard oil was measured by a laser induced fluorescence method. Coumarin153 was added into the lard oil and was used as a fluorescent material. Reduction rate of fluorescence intensity from the lard oil by the micro-bubble flow was higher than that in water flow. Removal patterns of the lard oil were observed by a microscope. It was found that the micro-bubble flows had higher cleaning effects compared with water flows.

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Effects of liquid volumetric flux J_L and flow pattern in a decompression nozzle on the mean diameter and number density of micro-bubbles generated by using a pressurized dissolution method are experimentally investigated. The bubble diameter and number density are measured by using a phase Doppler anemometry at the exit of the decompression nozzle. The flow pattern in the decompression nozzle was observed by using a high speed camera. The experimental results indicate that the diameter and number density strongly depends on the flow pattern in the decompression nozzle, and their characteristics are classified into three regimes: (1) few bubbles are generated when no cavitation occurs, (2) when bubble cavitation takes place, the mean bubble diameter keeps low values which do not depend on J_L so much and the bubble number density increases with J_L, and (3) the mean bubble diameter increases with J_L whereas the number density does not depend on J_L when flow pattern in the nozzle is sheet cavitation.

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A correlation based on the drift-flux model is proposed to estimate volume fraction of solid-phase in developed steady liquid-solid upward two-phase flows in vertical pipes. The distribution parameter and the drift velocity in the model are expressed by the six non-dimensional groups composed of input physical quantities and others. Their fundamental frames are given as follows:
   V_S = J_S/α_S = Co(J_L+J_S) − {1-(d_S/D)²}α_L^s V_ST
       C_o=A₁(d_S/D)^a{J_L/(J_L+J_S)}^b{J_S/(J_L+J_S)}^e(ρ_S/ρ_L)^f{(J_L+J_S)/(gD)^0.5}^h
          {ρ_LD(J_L+J_S)/μ_L}^j + B₁
       α_L=A₂(d_S/D)^k{J_L/(J_L+J_S)}^m{J_S/(J_L+J_S)}ⁿ(ρ_S/ρ_L)^p{(J_L+J_S)/(gD)^0.5}^q
          {ρ_LD(J_L+J_S)/μ_L}^r + B₂
By using these new expressions, the volume fraction of solid-phase can be estimated with higher precisions than the author's previous correlation and Bankoff-type correlation.

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