With recent research and development example, the compound utilization with the heat source equipment for the residence is proposed the solar energy utilization. For example, gas domestic hot water supply and heat pump heating and cooling system and combination example the contribution ratio of combined photovoltaic and heat system is high, if solar energy system can be operated under optimum conditions, and the energy consumption becomes an optimum. From the viewpoint of economical efficiency, environment, this report was evaluated on the effect (effectiveness of the system) of combined photovoltaic and heat system for the housing using the practical operation case.

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The wide use of photovoltaic and solar thermal hybrid systems is recommended in order to enhance the use of solar energy as one of the substitutes for oil. The panels that were made of amorphous silicon PV modules have been used successfully since several years ago as the absorber plates of the air collectors of solar houses. More effort should be done to build this kind of solar houses to increase the demand of solar energy. Hybrid panels can be used as the evaporators for heat pumps to put up a better performance. Further researches on this type of panels and systems are necessary to produce them commercially.

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Previous development of solar energy technologies was progressed from two sectors of thermal and photovoltaic utilizations. Presently, each of technology such as solar hot water unit and PV system is in commercial stage. From the viewpoint of effective use of solar energy, solar hybrid collector generating heat and electricity from the sun was developed. This is called solar co-generation from the meaning of produce or supply of heat and electricity. Although this is one of the most useful methods of solar energy, we can use effectively solar energy than before if fuel is produced by solar energy. One of the methods to realize this idea is solar tri-generation. In this paper, we propose the methods of solar tri-generation producing heat, electricity and fuel from the sun.

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The paper presents to discuss a historical evolution process of the primitive Carnot cycle to the modernized understandings, through which some prevalently accepted ideas and concepts embodied in the modern thermodynamics are also re-examined. Subsequently, the more detailed speculations on the modern Carnot cycle are exhibited, particularly, on the designated temperatures during isothermal processes from the viewpoint of energy conversion between heat and mechanical work and, further, extended to discuss the relations of more generalized thermal cycles including the polytropic changes as well as the related thermodynamics noticing the rigorous systematic understanding on the thermal cycles and the efficiencies.

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Rather old story of the equal area construction of Maxwell has been revisited and general applicability of it has been examined. It will be shown that though the equal area construction may work for van der Waals fluid at least, it may not be applied for general p-v-T type EOS.

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This paper was prepared for the One-Point Lectures of the TED-Conference, and deals with the fundamental knowledge of Thermodynamics for handling mixtures, so called a part of Chemical Thermodynamics. The main contents of this paper are the fundamental thermodynamic theories for mixtures, phase diagrams of binary mixtures such as H_2O-NH_3 and H_2O/CO_2/hydrate, and remarks for calculations of enthalpy and entropy. Many kinds of mixtures are lately used for the thermal and energy equipments, machines, plants and others, but most of mechanical engineers are not so much concerned with Thermodynamics of mixtures. For this reason, this presentation is a warning to the young students in the Department of Mechanical Engineering.

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This half-hour course of the one-point lectures deals with a liquid-vapor phase change: evaporation and condensation of materials. The drinking bird is one of the best tools for visualizing thermodynamics. This lecture introduces the bird to mechanical engineering students at Okayama with showing them some experiments to explain the phenomena. The heat pipe is one of the most excellent applications for thermal engineering.

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[in Japanese]

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Convection of air due to magnetizing force was modeled and numerically analyzed with and without a gravitational acceleration. Sample computation was carried out for convection in a cube heated and cooled from opposing walls. Depending on the strength and electric current to give magnetic field, various convection modes could be produced. This magnetizing force was found to disturb the conduction heat transfer heated from above for the air in a gravity field. When the magnetizing force is located against to the gravity acceleration, almost micro gravity field was produced to give conduction state of air heated from below in a gravity field.

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Two-dimensional numerical computations were carried out for natural convection of air in a cylindrical enclosure under a strong magnetic gradient field with and without a gravitational field. The magnetic susceptibility of air was represented by an inverse of the absolute temperature following Curies law. The axial location of the electric coil was changed to study the effect of the magnetizing force. The air was almost driven by not the buoyancy force but the magnetizing force even in a gravitational field. However, the air convection was greatly dependent on the axial position of the coil.

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Numerical computations were carried out for a convection of air in a rectangular box under a magnetic field gradient to investigate the influence of a strong magnetic field. The fluid in the rectangular box is heated from a vertical wall and cooled from an opposing vertical wall both isothermally, and thermally insulated from four other walls. The governing parameters are the Rayleigh number, the Prandtl number, and γ, which indicates the strength of the applied magnetic field. The magnetic field induced by an electric-circulating coil was numerically calculated by using the Biot-Savart's law. When the coil was placed near the hot wall, the thermal convection was enhanced, but when the coil was placed near the cold wall, the thermal convection was reduced due to magnetizing force.

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The natural convection of air was computed in an inclined cubic enclosure heated from one wall and cooled from the opposing vertical wall with one electric coil, which induces a magnetic field gradient. Length of the cubic enclosure was set to 0.064 m and the radius of the coil 0.05 m. Characteristic dimensionless values are the Rayleigh number, the Prandtl number, and γ, which indicates the strength of the applied magnetic field. Sample computations were carried out for the parameter ranges, Pr=0.71, Ra=10^5, γ=0, 5 and the inclination angleφ_2. The results revealed that the average Nusselt number seriously depends on both inclination angle and the magnetizing force strengthγ.

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The double diffusive convection at the freezing or melting in aqueous solution was numerically studied at the Prandtl number Pr=l3.4, the Lewis number Le=100, the buoyancy ratio N_0=0,l or 5 and the Rayleigh number Ra_0=l0^7. In the case of freezing, a thin boundary layer of concentration was formed near the surface of ice and the solute accumulated near the bottom of the vessel. In the case of melting, two thermal convections were formed at N_0=0, a multi-layered convection at N_0=1 and a concentration stratified layer with convection layers at N_0=5.

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A numerical and experimental analysis is performed for oscillatory natural convection in a square box heated at the lower half and cooled at the upper half of the side wall. The temperature oscillation in the water is measured by the thermo-couples and compared with numerical results obtained by a finite difference method based on the HSMAC formulaion. The relationship between the Rayleigh number and the temperature frequency is obtained, and the influence of the distance between the heated wall and the cooled wall are investigated.

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In a rectangular channel with heated below and cooled above, when the temperature difference is above a critical value, natural convection appears. This roll axis is perpendicular to the flow direction. When the through-flow is imposed on such convection, the flow pattern changes and roll axis become parallel to the flow direction. However, if the through-flow was very weak, the flow structure kept itself or changed only near the entrance region of the test volume. In this study, these three flow structures of mixed convection were visualized using thermo-sensitive liquid crystal suspended method and convection pattern map was presented.

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For natural convection in the geometrically complicated channel or natural convection caused by the accidental stop of driving system in forced convective channel, the convection flow is suppressed by flow resistance due to such channel itself or an equipped driving system, and the lopsided flow may take place. This could result in serious influences on the heat transfer in the channel. In order to investigate fundamentally the natural convection flow and heat transfer in such the channel, the vertical channel with rectangular cross-section was employed, in which both vertical walls were symmetrically heated with uniform heat flux and the flow resistance was given by small clearance between the lower end of channel and a wide horizontal floor. Flow pattern was observed by illuminating smoke filled in the channel and the heat transfer coefficient was measured. Heat transfer coefficient is discussed in connection with the flow pattern.

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Two-dimensional numerical computations have been conducted to investigate natural convection of liquid metal in a square cavity bounded by vertical walls at uniform of heat flux gradient and insulated horizontal walls. In any heat flux gradient ,k secondary small cells are formed and oscillatory convection is dominant. Mean Nusselt number, Nu^^^- becomes higher with increasing k since a large k causes the thermal boundary layer to be extremely thin. A practical correlation equation is derived for Nu^^^- depending upon k.

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Experiment was carried out for Czochralski convection of liquid metal under the rotatio nal and horizontal magnetic field. A gallium melt in the crucible was heated at the sidewall and cooled at the upper rotating rod. This crucible was set into the horizontal and the rotati onal magnetic field and the temperature in the melt was measured for several values of the rotational rates of cooling rod and the rotational frequency of magnetic field. The melt temperature was fluctuate and the amplitude and oscillation period were changed at each cases.

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Thermal convection of liquid metal in an enclosure is studied numerically and experimentally. Both rectangular and cylindrical enclosures are considered. Three-dimensional numerical calculations are carried out for the rectangular enclosures with aspect ratios Ar (length/height) 2 and 4, and for the cylindrical enclosure with Ar (diameter/height) 2. Dependence of the onset of oscillation on various parameters is investigated. Furthermore, oscillatory, three-dimensional flow structure is clarified. The structure is characterized by some rolls as well as cellular pattern. Some experimental results using liquid gallium (Pr=0.025) are compared with results of numerical simulation.

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Experiment for the natural convection of liquid Gallium in a cube is carried out with external electric current added at the center height of heated and cooled vertical walls under the uniform magnetic field that is horizontal to the hot and cold walls. Liquid Gallium in a cube is affected by the Lorentz force induced by the added electric current and magnetic field, resulting unexpected flow pattern may occur inside the cube. However, it is difficult to visualize the inside flow directly, temperatures along the hot and cold walls were measured and the average Nusselt number was estimated with and without added electric current. When the electric current is applied, the Nusselt number differs from that without electric current as the strength of external magnetic field is increased.

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Computational studies of natural convection heat transfer to air from an isothermal vertical plate (2D) and a vertical plate fin type heat sink (3D) in the open system are described. The dimensional governing equations with the appropriate boundary conditions have been solved for △T=30 by means of SIMPLE method. As the results for a vertical plate agree with existing results, the same concept of numerical analysis is expanded to 3D and applied to a plate fin type heat sink. It is shown that heat transfer coefficient of fin side plate agrees with the experimental results by Aibara, and the optimum number of fin for a plate fin type heat sink of 4cm×4cm is demonstrated.

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Natural convective flow and heat transfer around a row of vertical heated plates were investigated both analytically and experimentally. Main concerns are directed to an effect of plate numbers on the fluid flow and heat transfer around the plate arrays. In order to simulate the flow and temperature fields around the rows of plates, full elliptic equations for the momentum and energy transport were solved numerically using the computational domain that encloses the whole plates. The results showed that the present elliptic analysis well predicts the plume interaction and also the local heat transfer coefficients of the plates. The results also depict that the velocity profiles and induced flow rates in between the pairs of plates depend strongly on the numbers and situations of the plates. This also results in marked differences in the local heat transfer coefficients of the plates.

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Turbulent characteristics of a natural-convection boundary layer in air along a vertical plate heated at high temperatures have been investigated by using a particle image velocimetry and a cold wire. From the turbulent statistics measured at the wall temperature of 300℃, it is found that the effects of a strong heat on the turbulent behavior are quite small, and the profile measurements of the turbulent quantities in the boundary layer hold, the appearances observed under the conditions of low temperature differences. Namely, despite a remarkable increase in the wall temperature, the maximum intensity of velocity fluctuation occurs beyond the maximum mean velocity location. Simultaneously, the Reynolds stress <uv>^^^- becomes positive at the maximum mean velocity location and almost zero near the wall.

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When one or three ribs heated isothermally were placed on the lower plate of horizontal or slightly inclined two parallel plates, the local heat transfer around ribs was measured by means of Shadowgraph method and the effects of heat transfer on distance of parallel plates, inclination angle and spacing of the ribs were discussed. In order to examine the interaction of convection flow, the flow pattern was visualized by smoke. From above results, following conclusions were drawn: (1) the heat transfer is symmetry with centerline for horizontal plates (angle=0). (2) when inclined, heat transfer of single rib changes such that heat transfer on the higher sidewall keep unchanged and that on the lower and top sidewalls are very large. (3) when plate angle is changed, the center and lower rib in three ribs has a similar tendency in variation of heat transfer, but higher positioned rib doesn't have it.

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Effects of a conducting body on natural convection in an enclosure with a heat source at the bottom surface was studied numerically. It was found that the thermal conductivity of the body affected the flow pattern and heat transfer. At a Grashof number of 50000, the Nusselt number for a conducting body remained almost as high as for no body, while it decreased remarkably when the body was adiabatic. At a Grashof number of 200000, the difference in the thermal conductivity resulted in different flow patterns, although it had a little effect on the Nusselt number.

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A preconditioning iterative method is applied to the numerical computation of natural convection in a confined region by the SIMPLE algorithm. The preconditioning is carried out by multiplying the matrix which consists of the entries of the coefficient matrix of a linear system of equations. It is concluded that the preconditioning is quite effective especially for the linear system of equations whose degree of diagonal dominance of a coefficient matrix is weak, such as of pressure correction. The number of arithmetic operations with the proposed preconditioning iterative method is smallest in this study.

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In order to provide data relevant to an understanding of the relationship between the dynamic characteristics of a hot-film shear stress sensor and the thermal conductivity of the material under the sensor, 2D and 3D numerical simulations were carried out. From the results of 2D simulations, the values of shear stress were not able to be measured by the temperatures at higher Reynolds number since separated flow occurred. In 3D simulations, the sensor without a step was utilized. The heat transfer around a heater was analyzed.

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A sensitivity analysis based on adjoint formulation is proposed to generally evaluate the thermal boundary condition effects on convection heat transfer characteristics. An illustrative example is presented for natural convection heat transfer between horizontal concentric cylinders. The sensitivity function obtained from the adjoint computation enables us to predict the change of total heat transfer rate for arbitrary thermal boundary perturbations on both inner and outer walls.

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Microscale multiphase flow system will be a promising methodology in micro- and nanoscale technology. The present study focused on investigation of nanoscale particle motion in a microchannel detected by a micro-resolution particle image velocimetry (micro-PIV). Magnetic particles of 350 nm in diameter in the microchannel were controlled by the magnetic field, yielding decelerating fluid flow. When the magnetic field was removed, particles were dispersed rapidly by the Brownian motion whose theoretical diffusion velocity was equal to one obtained by the present micro-PIV system.

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An electrokinetic flow field in a microchannel was investigated by a PIV system using a microscope and sub-micron fluorescent particles. The present study focused on quantitative measurements of electroosmotic flow eliminating velocities of tracer particles induced by electrophoresis, which was calculated by measurement velocity in a cell, comprised of electroosmotic flow and electrophoresis. Quantitative velocity profiles of electroosmotic flow were obtained subtracting velocities of tracer particles induced by electrophoresis from measured velocities. It was observed that velocity profiles of electroosmotic flow had a reverse parabolic shape in the center region of the microchannel and were uniform near the wall.

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Two-fluid mixing phenomena were quantitatively visualized by a micro-resolution particle image velocimetry,(micro-PIV) in a T-shaped microchannel with two inlets, which was fabricated with silicone elastamer, i.e., polydimethylsiloxane (PDMS) using the replica molding technique. The objective of the present study was to investigate diffusion of particles affected by electrophoretic migration and electroosmotic flows. Particle velocities induced by electrophoresis were calculated from velocity profiles in a closed channel detected by a micro-PIV. Particles involved in a flow from the one side induced by electrophoresis were diffused remarkably when the electric field was applied to the junction area of the microchannel.

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A special thermal micro-cantilever was made by the micro-fabrication technology. It has differential thermocouple, electric heater and other thermocouple on its Si0_2 body of 260 μm length, Temperature measurement experiments for small metal lines of 5 μm width have conducted with the cantilever on SThM (Scanning Thermal Microscope) with the thermal feedback system under low pressure condition where heat conduction via ambient gas is negligible. Although passive method with no thermal feedback takes heat flow images affected both temperature and contact conductance changes, the active method with the feedback measures real temperature images of sample surface.

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Drag-reducing turbulent flows of dilute polymer solution are measured using particle tracking velocimetry (PTV). The measurements are done in a micro channel 2 mm in wall-to-wall distance for the Reynolds numbers of about 300 and 10,000. A double-pulsed Nd:YAG laser is used to illuminate 0.8 μm-diameter acrylic tracer particles. It is confirmed that the turbulent drag reduction in polymer solution (i.e., Toms effect) becomes more pronounced in small conduits like the present micro channel than in other larger channels and pipes. The mean velocity profile in drag-reducing flows looks like the laminar velocity profile. The turbulence statistics measured in drag-reducing flows have shown that the streamwise and wallnormal velocity fluctuations, when normalized with the friction velocity, are approximately of the same magnitude as those in pure water flows but that the Reynolds stress almost vanishes. Separate PIV measurements indicate that the presence of elongated structures of streamwise velocity fluctuations contributing little to the generation of the Reynolds stress is the reason for the measured turbulence characteristics in the drag-reducing micro channel flows

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Experimental studies are made on the effect of liquid film to gas-phase turbulence modification on air-water annular flow in vertically arranged round tube. Gas-phase turbulence structure and characteristics such as time- averaged velocity profile, fluctuation velocity profile, power spectrum, and auto-correlation coefficient are quantitatively measured by using the hot-wire anemometer. Measured values are quantitatively examined and compared with the single-phase flow. Followings are noted. (1) Time-averaged velocity profiles are modified to sharpened shape compared with single-phase flow. (2) Fluctuation velocity in axial direction becomes larger than that of single-phase flow through the all-radial position. (3) Turbulence in annular flow is modified to coherent structure, which should be affected by gas-liquid periodically moving wavy interface.

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Sufficient knowledge of Reynolds stress is indispensable to understand the turbulence structure and to develop a turbulence model in gas-liquid two-phase bubbly flow. There is, however, little information on the Reynolds shear stress as well as radial and azimuthal turbulence intensities, whereas many researches have concerned on the axial turbulence intensities in a gas-liquid bubbly flow in a vertical pipe. In this study, we utilized a pipe made of fluoro carbon which has the same refractive index with water, and which enabled us to measure the two velocity components simultaneously using LDV in air-water two-phase bubbly flow in vertical pipes. The measured result indicated that all the components of Reynolds stress are affected by the presence of bubbles. Bubble-induced agitation of a liquid velocity field was particularly prominent under a laminar flow condition. Turbulence enhancement as well as suppression due to the presence of bubbles was observed.

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This experimental study has performed on vertical, upward, gas-liquid two-phase flow through a round tube with an axisymmetric sudden expansion part (20 mm φ to 50 mm φ). The flow patterns in the case of the sudden pipe expansion were observed by using the high-speed video camera. The observations revealed that the sudden expansion flow patterns had the multi-dimensional behaviors, i.e., the singular phenomena in the sudden expansion part, such as straight-up flow, reattahment point, recirculating flow, deformation and break-up of the slug and bubble, etc., were clarified.

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Numerical simulations have been made on the flow and heat-and-mass transfer in a falling liquid film. The development of a two-dimensional wave was successfully predicted, which consists of a large solitary wave and ripple waves in front of it. Heat and mass transfer is enhanced by the wave, and the enhancement is remarkable in the case of mass transfer with high Sc number. Three-dimensional calculations indicate that a two-dimensional wave becomes unstable with the increase of Re number, resulting in U-shaped three-dimensional waves. The Sh number increases with the transition from 2D to 3D waves.

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In order to predict the free surface phenomena in pool, the interaction between the liquid flow field and free surface should be evaluated. In this study, we aimed at developing a new three-dimensional measurement system for surface elevation and liquid velocity profiles in pool water using an image processing technique and a laser focus displacement meter. The purpose of the experiments was to confirm the effectiveness of this new technique obtaining temporal and spatial information of surface elevation and inclination as well as particle positions. As a result, it was confirmed that the free surface position and inclination were measured by this technique within 0.1 mm and 0.7° deviation.

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A transition to turbulence occurs in a radial liquid sheet flow. A radial liquid film flow is generated by a water discharge from a thin cylindrical gap, which is constructed by the end of a circular pipe and the flat surface of a disk. Sudden laminar-turbulent transition occurs in the liquid sheet when the Reynolds number exceeds a critical value, Resulting both in the perforation and the disintegration of the sheet under extremely high Reynolds number. The configuration of the liquid changes from the liquid sheet into ligaments and drops in the disintegration process. The configuration is measured by photo-sensing. LDV measurement synchronized with photography and photo-sensing reveals that the production process of small drops.

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Many accidents due to vapor explosion occurs in various industrial fields in recent years. Although vapor film collapse behavior is a key phenomenon for the trigger of the vapor explosion, it is very difficult to make visual observation at the vapor, explosion. In the present research, vapor-liquid interface behavior at vapor film collapse was experimentally observed and was qualitatively analyzed with visual data processing technique.

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There is a growing need for the ways of treating non-utilized heat effectively for reducing CO_2 emission. Direct-contact evaporative heat transfer between two kinds of immiscible liquid can be utilized for such technological applications. In order to meet the demand for heat with temperatures close to the ambient, for example, a fundamental experiment was carried out on the evaporating phenomena around a continuous horizontal interface of water (upper) and PF5050 (bottom) liquid pools. This interface was heated by downward jet flow of water, and unique evaporation phenomena of PF5050 appeared. The evaporation rate was much increased due to the effect of the intensity of jet impingement.

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A steam injector is a simple, compact and passive pump and also acts as an high-performance direct-contact compact heater It's performance depends on the phenomena of steam condensation onto the water jet surface and heat transfer in the water jet due to turbulence on to the phase-interface. To develop high performance compact feedwater heater, it is necessary to quantify the characteristics between physical properties of the flow field. We .carried out experiments to observe the internal behavior of the water jet as well as measure the velocity of steam jet using a laser doppler velocimetry. As soon as the steam injector start up, the stable water jet was formed in the center of mixing nozzle. The analysis was also conducted by using CFD code, and confirmed that the steam has a high-performance direct-contact heater that was suitable for compact feedwater heater.

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Improvement of CHF requires that the cooling liquid can contact the heating surface, or a high- wettability heating surface, even if a vapor bubble layer is generated on the surface. From this point of view, an experimental study to investigate surface wettability was performed by use of oxide semiconductor-coated materials under a γ ray irradiation environment. The results showed that the surface wettability changed significantly or that highly hydrophilic conditions were achieved, after 250kGy irradiation of ^<60>Co γ ray.

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Improvement of CHF requires that the cooling liquid can contact the heating surface, or a high- wettability heating surface, even if a vapor bubble layer is generated on the surface. From this point of view, an experimental study to investigate CHF was performed by use of an oxide semiconductor-coated material under a γ ray irradiation environment. The results showed that CHF of oxidized titanium was improved up to 100% after SOOkGy ^<60>Co γ ray irradiated.

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Effect of non-condensing gas on the condensation process at the liquid-vapor interface is studied using the DSMC method. The simulation results show that the condensing flow causes an accumulation of the non-condensing gas in the vicinity of interface which increase the resistance and reduce the condensation heat transfer rate. Even if the concentration of the non-condensing gas is low in the bulk phase, the non-condensing gas is much accumulated at the interface. The paper indicates the possibility of low values of the experimental condensation coefficient is due to the existence of non-condensable gases.

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This paper deals with the liquid film dryout and re-wetting behavior under BWR (Boiling Water Reactor) condition. The re-wetting behavior has not been made fully clear. Therefore, the transient BT (Boiling Transition) tests performed with BWR fuel moke-up bundle. 12 thermo-couples were installed in one of heater rods at same radial direction. The test results showed that the BT firstly occurred at just upstream of the spacer, then, BT propagates to upstream, and finally rewetting occurred from upstream at each interval of the spacers. It was also found that the re-wetting propagation velocity depends on the wall super heat temperature.

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