A new probe for groundwater flow measurement using a single borehole has been developed, which provides a simple and economical way to estimate the flowing velocity and its direction simultaneously. The principle of the measurement is based on mixed convection temperature field around the vertical heated cylinder subject to a uniform lateral flow. It is found by numerical analysis that the magnitude of temperature deviation from the concentric field is proportional to the strength of lateral velocity. A simple probe consisting of an electric heater in the center and thermistors around it has been built and its performance is examined by a calibration system, which is a two-meter long water tank filled with sands. According to the calibration, a good correlation has been obtained between the temperature deviation and the lateral water velocity (Darcy velocity). In order to simulate more practical situation, we also examine a case, where the rectification material fills the space between the flow meter and the perforated casing pipe, and an equally good correlation has been confirmed. A few field tests have proven promising results and future commercial use.

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The present study aims at improving the impinging jet heat transfer by placing an open-cellular porous plate on a heated surface, on which a circular jet nozzle with a flange is installed, and thus the porous plate is bounded by the heated surface and the flange and is expected to act as a heat sink. In the experiment, nitrogen gas was used as a coolant and Ag, Cu, Ni and Ni-Cr porous plates having various porosities, pores per inch and thicknesses were examined. It is found that the impingement heat transfer can be augmented prominently by placing an appropriate open-cell porous plate in a heating section.

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Boiling in packed bed is an important problem related to the geothermal system, the heat pipe, post accident analysis of liquid-cooled nuclear reactor debris and nuclear waste disposal. In this paper, the effect of structure of packed bed on boiling phenomenon in multiple packed beds filled with water has been investigated by numerical analysis. Two-dimensional boiling model in multiple packed beds has been proposed to obtain the distributions of water saturation, vapor pressure and temperature in multiple packed beds. In multiple packed bed composed of different particle beds, the water content becomes discontinuous at the interface because of the difference of the water characteristics between two layers. It was found that the water saturation and velocity of vapor strongly depend on the structure of multiple packed beds.

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We experimentally investigated the characteristics of dissolution rate of CO_2 into water in porous media and the behavior of emitted CO_2 from porous media in sequestration conditions. Dissolution rate of CO_2 were summarized as a relationship between the modified Sherwood number and Reynolds number. Liquid CO_2 shows a high mass transfer rate as compared with gas and supercritical states. Carbon dioxide is emitted from porous rock in bubble form with diameters of about 1mm in gas state and much finer in liquid state.

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Drying process of porous media was analyazed by using experimental visualization of water content and temperature distributions. The variation of water distribution in the thin porous media was observed from the image data recorded by a back-lighting method. For the visualization of the temperature, encapsulated liquid crystal is applied to the test section. It is found that the experimental imaging enable us to examine the characteristics of drying phenomenon inside the porous media.

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The effects of porous material's pore diameter and wet-bulb temperature of drying media on solute distribution contained in the material after drying were investigated experimentally. Glass beads (mean diameters of 110, 400 and 800μ m) packed beds which contained pure water; sucrose; NaCl; mixed(sucrose and NaCl) aqueous solution were used as porous sample material. From these results, the smaller pore diameters and the lower wet-bulb temperature caused the sucrose contained near the surface to increase. The sucrose distribution in the material was effected, but almost all of amount of NaCl remained at the surface of the material in every experimental condition excluding the mixed solution. In case of the mixed solution, the amount of sucrose contained near the surface after drying was increased by higher NaCl concentration.

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In melting process of a dynamic ice thermal storage system, warm water penetrates through a bed of ice particles with forming water channels. We have studied melting characteristic of a packed bed of ice particles with forming a water channel numerically. A numerical model assuming Darcy flow shows close agreement with experimental data about melting rate and the shape of ice bed. Melting characteristics of packed bed is impaired by expanding of a water channel and decrease of permeability of water into ice bed. Additionally, we discussed a mechanism of the melting process from the numerical results.

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We have investigated the freezing of water involving many small particles experimentally, using the particles of SiO_2 and Al_2O_3 which have the surface electric charge of the minus and the plus in water respectively. The freezing layer can be divided into three and two critical freezing rates are defined, considering the trapped and swept phenomenon of particles due to freezing. It was found that the critical freezing rates largely depended on the concentration of particles in water. By mixing SiO_2 with Al_2O_3 particles, the critical freezing rate can be largely changed because the bond of Al_2O_3 and SiO_2 particles makes the surface charge electrically neutral.

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In this paper, experiments were conducted to study the drag-reduction and heat transfer performances of a newly synthesized zwitterionic surfactant solution (Oleyl trimethylaminimide) in a two-dimensional channel. It was found that the novel zwitterionic surfactant solution showed both drag and heat transfer reduction characteristics, which were affected by concentration and temperature. For enhancing heat transfer of the surfactant drag-reducing flow, a destructive device of Venturi type, named Block, was designed and used in the experiments. It was found that the Block device can enhance the heat transfer performance of the novel zwitterionic surfactant solution to some extent while having a very small pressure drop penalty.

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It is known that small quantities of surfactant additives can greatly reduce the friction factors by the formation of rod-like micelles in the flow of a heat transfer medium. However, heat transfer coefficients also reduce during such a drag-reducing surfactant solution flow, and as a result, heat exchangers with a larger heat transfer area would be required. This paper presents an experimental investigation on the heat transfer characteristics in a two-phase flow of a drag-reducing surfactant solution (TTAB+NaSal, the concentration is 500 and 1000 ppm) and polystyrene particles. The objective is to examine heat transfer enhancement with polystyrene particles into drag-reducing flows. Heat transfer enhancement was larger for surfactant solution flow than that for water flow. This indicates that polystyrene particles have the effects of not only mixing flow, but also breaking micelle structure for surfactant solution flow.

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In surfactant solution (TTAB+NaSal) - air two phase flow in a vertical pipe, the pipe friction factor and heat transfer coefficients were investigated. The straight circular pipe of D=5.05mm in diameter and L=2900mm in total length was used. Fiction factors and heat transfer coefficients for surfactant solution - air two-phase flow were larger than those for single flow, but smaller than those for water - air two-phase flow. This seems to be due to drag reduction effects of micelle structure formed. The range where friction factors and heat transfer coefficients have decreased were found in surfactant solution - air two phase vertical flows compared with horizontal flows. This seems to be due to differences of flow pattern.

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In order to investigate the optimum geometric condition for a heat transfer augmentation technique using the Barus effect of visco-elastic fluid, heat transfer experiments have been performed in a cavity. In this paper, the length of a cavity mounted on one side in a channel flow was changed from 50mm to 200mm. The results indicated that the mean Nusselt number on the cavity bottom in the cases of visco-elastic fluid becomes smaller than that in the corresponding cases of water under the present conditions, but it was found that the visco-elastic fluid improved heat transfer characteristics behind the upstream wall of the cavity at least.

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This paper describes flow and heat transfer characteristics of ice slurry in a curved pipe. Ice slurry is a mixture of water and ice particles about 1〜5mm in diameter, which is used as a phase change material. Experiments were carried out under the some parameters of ice packing factor(IPF), velocity( V_m), radius ratio(R/r) and ice particle size(d_p). Heat transfer coefficients of four points (top, bottom, in, and out) around a pipe were measured. It was found that heat transfer in a curved pipe affected second flow reduction by ice particles and interaction of latent heat.

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In recent years, slurries of ice have been commonly used as environmentally-friendly secondary refrigerants because they provide solutions to such issues as establishment of uniformity in electrical loads, effective use of unavailable energy for use and savings in energy. In addition to ice-slurries, ice-water mixtures in slurry-state have also been put to practical use at temperatures below 0℃. A binary mixture such as a water-solution has a solid-liquid coexistent region where a solid phase coexists with the liquid phase. This solid-liquid phase can be used as a high-performance secondary refrigerant if it is possible to form a two-phase flow involving the two phases. Another possibility is that it can also be used as a natural secondary refrigerant because the constituents of the refrigerant are substances existent in the nature.

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A two-dimensional numerical simulation of Rayleigh-Benard convection in a rectangular enclosure heated from below and cooled from above has been conducted with non-Newtonian phase-change-material (PCM) microcapsulate slurries with latent heat capacities. The formulation of the mathematical model in dimensionless co-ordinates and discretization of the governing equations has been done using the finite volume method. Both flow and heat transfer characteristics are discussed about Rayleigh-Benard natural convection with PCM microcapsulate slurry, which exhibits pseudoplastic non-Newtonian fluid behavior and a peak value in the specific heat capacity. The viscosity of the present PCM microcapsulate slurry is assumed to follow the Ostwald-de Waele power law fluid model with the power-law index n and the consistency coefficient K. The effects of the mass concentration and the aspect ratio Ar on the natural convection are described respectively.

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A Numerical study has been performed in order to investigate the heat transfer characteristics of a hydrate slurry transported by a visco-elastic fluid flowing between parallel plates with a one-sided cavity. The length were changed in three steps from 50 to 200mm, while the rib height, rib length and the width of wide flow path were fixed. The results were compared with those in the case when water is used as transportation media of hydrate particles. From the results, it is found that hydrate particles flows over the cavity without penetration in the case when solvent is Newtonian fluid (water). On the other hand, hydrate particles are observed effectively to penetrate into the cavity by Barus effect in the case of visco-elastic solvent. This causes effective heat transfer from the bottom wall of the cavity.

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An experimental investigation has been made regarding a turbulent structure of a horizontal channel flow with microbubbles. In the present study, we approached by two techniques, one is a Borescope-PIV, and another is a measurement using an optical shear stress sensor. In bubbly flow, the PIV measurement is hampered by existence of a large number of bubbles in optical path. It enables clear measurements of bubbles and liquid phase from closer distance by using the Borescope. For optical shear stress sensing, we have developed a new signal processing, which enables to measure in bubbly flow. The process classifies original signals into signals from tracers and microbubbles. The experiments have been carried out for flow conditions with Reynolds number ranging from 5,000 to 10,000 and void fraction up to 1.0%.

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Effect of surface wettability on friction coefficient of horizontal circular pipe has been studied experimentally. We tested three cases; one is a normal glass tube(CASE 1) and the others are aluminum(CASE 2) and glass(CASE 3) tubes with super-water-repellent(SWR) wall. For CASE 2 drag reduction was observed by 20% compared with the others in single-phase laminar flow region, while drag coefficient of CASE 2 and 3 was increased in two-phase flow region.

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In order to derive a possible path for developing a large eddy simulation (LES) applicable to high Reynolds-number turbulent flow, a hybrid approach connecting LES with the Reynolds-averaged Navier-Stokes (RANS) modeling in the near wall region is studied. In contrast to most of the previous studies, an advanced non-linear eddy-viscosity model and a higher order extension of the generalized gradient diffusion hypothesis model are introduced to resolve near-wall turbulence and turbulent scalar transfer more correctly. The proposed model is applied to fully-developed channel flow with various grid resolution. The present model provides encouraging results for developing this kind of hybrid LES/RANS model.

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We carried out a numerical analysis of three-dimensional cavity flow by finite difference method. In time marching method, 2nd-order and 3rd-order Adams-Bashforth method applied to convective term and Crank-Nicolson method applied for viscous term. For other spatial derivatives in Navier-Stokes equations, we applied high-order-accurate finite-difference scheme. Especially, we investigated the effect of numerical viscosity. The results of computation compared with Lo et al's result. The maximum velocity near the bottom wall became large with decreasing the value of numerical viscosity.

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The flow inside the bending pipe conduit has been researched for a long time. But, there are few researches concerning the flow inside the passage in the rotating duct. In this investigation, three-dimensional flow analysis is performed in the curved duct with rotation. In this work, fluid is treated as incompressible flow, so Poisson equation for the pressure should be solved. The residual cut method is employed to solve the Poisson equation. In the time integration, the Adams Bashforth method applied to the convective terms and the Crank-Nicolson method applied for the viscous terms. As a result of this investigation, constitution of the secondary flow by curvature and Coriolis force became clear.

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Direct numerical simulation has been performed for the turbulent heat transfer in a channel flow obstructed by square ribs at Re_τ=80 and Pr=0.71. The constant wall temperature difference was applied between the walls for thermal boundary condition. The remarkable enhancement of the heat transfer is observed through the averaged Nusselt number Nu by comparison with the channel flow without the ribs. In particular, the local Nu increases around the upstream of the rib owing to the existence of the strong horseshoe vortices. The thermal turbulence statistics and the visualization of the instantaneous temperature fluctuations are also obtained to examine the effect of the ribs on the thermal field.

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Direct numerical simulation results of the three-dimensional separated flow and heat transfer around a backward-facing step of channel expansion ratio 1.5 and step aspect ratio 36.0 are presented. The finite differnce method was used in the Reynolds number Re from 300 to 1000. The flow is steady up to Re=500 accompanying the longitudinal vortices near the side walls, bringing about heat transfer enhancement there. The flow becomes unsteady at Re=700, resulting in the maximum Nusselt number in the channel central region far downstream of the time averaged reattachment point. At Re=1000, a severely complicated unsteady three-dimensional flow brings about a complex thermal field. The importance of the three-dimensional calculation of the unsteady flow is presented even in a very large step aspect ratio.

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The flow field through Y-branch (θ=60°) of square channel is measured using multi-point LDV system and characteristic of split flow is discussed by comparison with T-branch of square channel. A mean velocity vectors indicates the difference of the shape of separated bubble and position of accelerated flow. A reattachment length is longer than T-branch of it and movement of reattachment point and frequency of movement is similar tendency.

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Experiments of natural convection for a horizontal cylindrical annulus of the inverse relative gap width Di/L=6.7 were carried out with water in the range of Rayleigh number from 8.23×10^2 to 2.16×10^5, in which the unsteady flow pattern is characterized by the 3-D spiral flow. In order to clarify the heat transfer characteristics, flow patterns were visualized by adding the tracer particles of nylon to a flowing fluid. A stable crescent-shaped flow pattern is observed at low values of the Rayleigh number, but the flow does not develop completely into the upper portion of the annulus. As the Rayleigh number is increased, counter-rotating cells are appeared in the longitudinal direction and the flow pattern becomes a 3-D spiral flow. Then the flow reverts to the stable crescent-shaped pattern developed fully in the upper portion of the annulus at about 3×10^3 of the Rayleigh number. Heat transfer characteristics can be explained well from the flow patterns revealed by the flow visualization.

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This study investigates the influence of temperature-dependent physical properties in drag-reduced flow to clarify at which location temperature should be changed in order to contribute to drag reduction, by effecting wall beating so as to arrange a vertically and longitudinally "non-isothermal field" in channel flow. Temperature profiles have been measured by a fine thermocouple probe. Non-isothermal Field causes fluctuation of pressure gradient. Temperature profiles was changed by Non-isothermal field.

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This experimental work is to investigate film cooling for slot injection into a separated region of very thin turbine blade. The purpose of this research is to clarify the feasibility of the turbine blade which has been thinned the thickness. With such a thin turbine blade, as flow separation occur on the pressure-side, so film cooling practice in that kind of flow filed has not been well established. The experimental results showed: followings a reattachment length is about five times step height. Characteristic of adiabatic effectiveness in the pressure-side wall depends not only blowing ratio but also situation of a separated shear layer and shape of turbine blade.

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This paper describes the result of the numerical analysis of the heat transportation in a double tube. It was found that a unique type of oscillatory flow was induced in the double tube when a simple sinusoidal reciprocating flow was imposed at one end of the tube. The unique oscillatory flow was a reciprocating flow superimposed with a steady circulation flow. The present double tube can transport heat with a high efficiency that is mainly attributed to the heat transportation by the steady circulation flow.

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Resin pellets are plasticated inside the heating cylinder not only by heat transfer from outer heaters but also by shear heating of a rotating screw. This paper introduces, from the viewpoint of heat transfer, the following important phenomena dominating the plasticating process of resins; (1) temperature distribution inside flowing melts at the nozzle and screw channels, (2) heat flux changes at the inner surface of the cylinder, (3) torque axial distributions along the inner surface of the cylinder. The break-up phenomenon of the solid-bed (solid unmelted resin pellets) is also described based on visualization results and correlation with the above-mentioned measurement results.

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The probe (healer) was inserted in the flowing polypropylene / mica composites, and the information heat transfer behavior from the probe to the molten composites was examined experimentally. As a result, the heat transfer coefficient increased with an increase of the mica content, and showed a clear flow velocity dependency. Moreover, it was found that the boundary flow velocity of the conduction heat transmission and the heat transfer by convention was 0.12-0.18mm/s from the relation between equivalent conduction layer thickness and the flow velocity. Prandtl number of the PP/Mica composites increases as the viscosity increase, and decreases dependently on the flow velocity and temperature.

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In the melting of high-polymer material on industrial applications, there are unsteady flow phenomena on its non-Newtonian properties. For the stability and controllable evaluations of flow and heat transfer, the unsteady interface phenomena in melt-front of high-polymer materials (PP) with several flow configurations (rectangular flow with 5mm & 1mm thickness, with/without artificial surface control) are shown as local and unsteady geographic shape of the gas-liquid interface experimentally with the visualizing images of high-speed CCD video. From experimental results and considerations, the gas-liquid interface changes its shape properties time-dependently, and the two-way transitions of phenomena and all-over instability are detected in the system, which mean that one is from the center to wall (fountain-flow-like), another is from near-wall to center by non-uniform slipping phenomena at near-wall region. These results is important in building the flow and heat transfer three-dimensional mechanism models of high-polymer flow by ejection process in rectangular flow system. As a result of this experiment, this research opens a new dimension by utilizing Wavelet in analyzing flow under artificial conditions.

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In contact line with gas dissolution, the Marangoni flow that originates in the concentration difference appears. More intense flow is generated when the relative movement etc. of the solid phase to the liquid phase act in this area. At this time, a capillary force is caused for the solid surface. In this research, we detected a capillary force and concentration change in the limited part in the contact line with gas dissolution. And, the result that the concentration rise is promoted by the relative movement of the solid phase was obtained. Moreover, it is suggested that there be correlations in a concentration and a tangential force change.

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The prediction of a foaming flow process is difficult because temperature, density, and thermal conductivity of polyurethane resin are changed greatly caused by heat generation resulting from the two-liquid mixture of polyol and polyisocyanate. Therefore, simulating the precise behavior of polyurethane foaming flow is very effective for reducing the development period and production costs. In this study, reaction of heat generation, density, thermal conductivity for polyurethane resin is formularized by experimental results. A foaming flow simulation was then developed by applying these formulas in the foaming flow process of polyurethane resin to a 3D flow simulation program. The following results are obtained by having compared analysis value with an experiment value. (1) Resin temperature can be calculated with precision less than error ±10℃ even if wall thickness and mold temperature are changed. (2) Specific volume can be calculated with precision of error ±8% even if wall thickness and mold temperature are changed.

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In this study we developed a new molding process called "Melt Replication Process" to fabricate thermoplastic products with 3-dimensional geometry, thin wall, large area, precise microstructures, high optical-transparency, low residual stress and low birefringence under very low pressure less than 10MPa. Furthermore, we demonstrated its applicability to display parts and μ-TAS(Micro-Total Analysis Systems) chips. From our experiments using COP(Cyclo-Olefin Polymer), the products with microstructures ranging from tens of nm to hundreds of μ m could be fabricated with transcript ratio over 95% and with very low pressure within short cycle time. Particularly, in the case of μ-TAS chip which has pillars with 20μ m in diameter and 50μ m in height, high replication ratios larger than 95% could be attained. Furthermore, the homogeneous transcription of microstructures over the large surface area of the molded product was confirmed.

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This paper deals with a local laser heating technique using photochromic-dye. He-Cd laser was used as excitation light source to actively control the radiation absorption coefficient of the dye added polymer material, and Ar^+ laser was used as heating light source. Both experimental and numerical simulation studies were carried out to elucidate the characteristics of the present technique. The results showed that the radiation absorption coefficient distribution in the sample thickness direction and the color attenuation effect of the dye during the heating had large effect on the temperature increase. According to the obtained knowledge, laser transmitting welding process for transparent polymer material was successfully realized.

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This paper deals with a development of cutting method for plastics using diode lasers. Laser cutting is based on the removal of molten material due to heat generation by laser irradiation. However, most thermoplastics tend to be transparent to diode lasers; it is difficult to cut the truly transparent material. In this study, we have investigated the possibility of diode-laser cutting of the transparent plastics using a thin coat which is added a particle of pigment absorbing near-infrared (NIR) radiation but transparent at invisible wavelength on the surface of workpiece. The influence of absorbance of the NIR-absorbing coat and the condition of laser radiation on the cutting ability have been studied

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