Loop heat pipes (LHPs) are heat transfer devices whose operating principle is based on the evaporation/condensation of working fluid, and use the capillary pumping forces to ensure the fluid circulation. In this paper, the influence of groove shape on LHPs' performance was investigated by calculations with steady-state model, and experiments with a LHP which is able to exchange wicks. As results, in the case of only axial grooves, it was found that there are the existences of optimum width, depth, and number to get down the evaporator temperature. To make maximum heat transfer greater, it was revealed that groove shape should be designed to minimize the sum of the pressure losses at contact surface and axial grooves.

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In present study, we investigate effect of heterogeneity of porous medium on gas saturation after drainage and imbibitions processes. The heterogeneity is modeled with the packed beds layered with different glass beads of grain diameter. The packed beds have two types of heterogeneity in serial and parallel directions with respect to the mean flow. Initial gas saturation is strongly affected by capillary entrance pressure at the interface of heterogeneous porous structures.

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We applied the theory of a psychrometer to develop a humidity monitoring system by using porous ceramics as a sensing element. The effects of porosities and pore size distributions on water transfer were investigated theoretically and experimentally. Several types of cylindrical porous ceramics were used. In addition, we compared the moisture transfer coefficients / permeability coefficients. The results showed that capillary water transfer were higher in the conditions that porosity was laeger and pore size distribution was wider. The water transfer by pressure difference were higher in the conditions that mode diameter was laeger.

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A new molding method using high humidity hot air as heating media was developed. We constructed a laboratory-scale apparatus for concluding basic experimental studies. Packed beds of silica sand coated with/without phenol resins or sugars as an adhesive agent were used as the material. During the initial stage of heating with high humidity air, the temperature of the packed bed uniformly rises rapidly by steam condensation. Results of molding tests indicated that the relationship between the wall temperature of the heating section and the dew-point temperature of the heating media, for regulating the condensation in the packed bed, should be optimized to improve the quality of products and to reduce the heating time.

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Pavement with water retentive materials is one of the effective countermeasures to urban heat island. But there is a problem that the evaporation performance of the materials deteriorates due to unavailable residual water in the pore structure. As a measure of solving the problem, using the granular porous materials is suggested. In this paper, granular tuff loams with different particle sizes are used for experiment of drying test with thermohygrostat chamber, and the effect of particle size to evaporation performance of the material is evaluated.

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Surfactant flooding which reduces the interfacial tension between oil and water is one of the promising enhanced oil recovery (EOR) methods. We should improve the efficiency of this scheme to reduce the cost. In present study, we proposed gas injection before the surfactant injection to improve the efficiency. The pore-scale mechanisms of surfactant flooding were visualized by means of X-ray tomography. The oil recovery increases with gas injection preceding surfactant especially for oil wet porous media.

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A sphere-packed pipe (SPP) was scrutinized to clarify the complicated turbulent flow field by means of PIV measurement. The geometrically complicated system was visualized by matching refractive index of acrylic resin as the channel material and Sodium Iodide solution as the working fluid. The visualization experiment was conducted with Reynolds number based on the sphere diameter and Darcy velocity of 5,000. As a result, it was found that high velocity regions appeared in the vicinity of packed sphere near penetrating paths formed in the SPP. In addition, it was clarified that turbulence energy was mainly generated in the large velocity shear regions formed near the pipe wall behind the packed spheres.

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Visualizations of gas-liquid two-phase flows in simulated porous media microchannels were performed to understand the dynamics in porous media. The channel consists of two junctions that simply simulated a porous flow-field. Two types of flow patterns, (i) water single phase flow at the one side and two-phase flow at the other side and (ii) two-phase flow at both channels, were observed at the simulated porous region. Pressure differences were estimated for both flow patterns and the results show that lower pressure drop is possible for the former pattern. It is expected that providing water single phase pass can reduce pressure loss in porous media.

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By tight supply of power after the Great East Japan Earthquake, the use of renewable energy and unused energy has attracted attention. In this situation, opinion such as "a large amount of heat is thrown away to sea water in thermal power plants. You should use more of this low-temperature waste heat" is seen here and there. Cause of such misunderstandings would be a lack of knowledge about exergy. In this paper, the results of exergy analysis and that of enthalpy analysis are compared to show the effectiveness of exergy analysis.

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The use of grains that has bacillus like salmonella may have lost domestic animal's health. To avoid this problem, we have devised a new process. The process involves shock heating by piston compression using the high pressure exhaust gases. Experiment results show that the maximum pressure increased and then the heating times reduced to 120μs, as the equivalence ratio increased. And the process proved to be able to sterilize the bacillus about 96%. We found that both high pressure and heating time affects the sterilization, and that the heat treatment of grains can sterilize bacillus.

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The imploding detonation of a propane-oxygen mixture was used to generate underwater shock waves in a sample holder. We used the experimental apparatuses whose sizes of the main combustion chamber are 60 mm, 150 mm, and 400 mm. The experimental results show that maximum pressure at the implosion center was 150 to 18000 times higher than the initial pressure. Although the maximum pressure in the exit of a sample holder changes with the sizes of experimental apparatus, pressure increase speed is almost constant. We found that the highest pressure in the end of a sample holder can be increased by expansion of the size of the main combustion chamber, and that we can perform scale-up and automatic operation of sterilization equipment by use of this high-pressure generation method.

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The accident at Fukushima Daiichi nuclear power plant happened on March 11, 2011 revealed that the long station blackout causes a possibility of breakout of nuclear reactors. This accident may occur not only by tsunami or earthquake but also long term absence of operators. The author has proposed a cooling system that can continue cooling the nuclear reactor without external electric power supply or the support of operators. This system is composed of natural convection cooling tower and heat exchangers. Power required to operate the system is supplied by the decay heat of nuclear fuels. This paper describes the performances of natural convection cooling heat exchanger and feasibility of the system.

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A large-eddy simulation of a buoyant plume past a bluff body (BB) is performed. The modified Rayleigh number based on the total heat input and the BB diameter is set at 1.2x10^<10>. The entrainment coefficient showed definite increase in a wide range above the BB in the case with an adiabatic BB. Moreover, turbulent intensities, skewness factor and flatness factor in the same case also show considerable difference with other cases; with a heated BB and without BBs. These variations suggest that vertical vortices exist in the central region above an adiabatic BB and are relevant to the increase of entrainment there.

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In hydrogen stations for fuel cell vehicles, a rapid filling process of high pressure hydrogen to a tank on the vehicle is requested, and there are some concerns that possible condensation of residual water at a low temperature section in the fuelling system leads to occlusion in pipes or instability of flow system. In the present investigation, dew and frost point measurement system for residual water in high pressure hydrogen utilizing cooled mirror technique with original image analysis had been designed and developed. Frost point measurements with hydrogen-water standard gases under conditions of 5〜10 MPa, 5〜55 ppm were carried out systematically, and frost point estimation procedure was also developed utilizing new frost point data.

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The reaction mechanism and growth rate of TiN film by thermal chemical vapor deposition has been investigated. Firstly the growth rate increased dramatically with the distance from the heater inlet until almost unform temperature zone. After the zone ,the growth rate decreased exponentially with the distance. From the fact,the coating process could be controlled by mass transfer of the reactant with having the gas phase reaction after the zone.From the analysis,the activation energies for the surface reaction and the gas phase reaction were 88.3 KJ/mol and 26.0 KJ/mol, respectively.

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In this study, numerical simulation for titanium-nitride (TiN) coating in the tubular reactor by thermal CVD has been conducted. Growth rate profile of TiN along the axial position of the reactor was predicted by solving two dimensional heat and mass transfer equations with having the effects of solidification in the gas phase and surface reaction under Poiseuille flow condition. The analyzed rate constants for the solidification in the gas phase and surface reaction were used. The calculated profile agreed qualitatively with the experimental results for the dependence of the setting temperature. However, the dependence of the growth rate on the total flow rate into the reactor could not be explained by the calculation.

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Flow characteristic of compressible flow in a micro-tube was investigated numerically. In conventional researches, the flow characteristics have been investigated under the assumption of isothermal flow. But it is not sure the limitation of condition in which we can use the isothermal flow assumption. In this report, the mass flow rate through the micro-tube was examined considering with temperature decrease caused by gas expansion, temperature increase caused by viscous dissipation, heat conduction and convection. The results were compared with the isothermal flow and the limitation of the assumption was discussed in the combination of pressure ratio and tube length.

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The purpose of this study is to find out influence of wettability on condensate film behavior. We used two material balls, Alumina Ball (AB) and Coated Alumina Ball (CAB). CAB have higher wettability than AB. This study was conducted by streaming the humidity-air over the porous media surface in a chamber covered by ambient-air. Condensation film behavior in the system was visualized by use of video camera. The main result mention that condensate film behavior of AB media was channel flow, whereas its of CAB media was almost drop wise condensation under low humidity-air temperature.

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Aiming at solution of the problem that the heat exchange speed of zeolite heat pump is slow, the time which 1 cycle takes is long, direct contact type particle packed bed's performance were examined focusing zeolite particle layer height. The findings by as a result making zeolite particle layer height high of there having been without time influence to saturation adsorption temperature, having more influence on the quantity of heat used for desorption per unit mass of the zeolite in a test section downstream site was acquired. As a result ,we found out that the direct contact heat exchanger had the advantage of making a particle layer thin.

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Thermal conduction and motion of air bubbles in packed bed of polystyrene particles during external heating have been investigated experimentally. The packed bed was consisted of a cylindrical glass vessel and polystyrene particles. The external heating rate varied from 50K/h to 500K/h. The setting temperature was 523K. The initial porosity of the packed bed was 0.41. The higher the external heating rate made the more the temperature difference along radius direction of the vessel and made the bigger the bubbles of air in the molten packed bed. Furthermore, it was observed that the bubbles moved upward with decreasing their sizes at steady state.

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Blowout experiments of methane-air diffusion flame by using a water vapor vortex ring have been performed. The water vapor vortex ring was produced by a single droplet impact onto a heated flat plate. The blowout probability was measured. The process of water droplet impact on the heated wall was observed by using a high speed camera. The boiling behavior and condition to generate the vortex ring were clarified. It was found that the wall temperature at 250℃ was the most effective condition for the flame extinguishment.

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Fire extinguishment experiments were conducted for liquid pool fire using water mist contained with 0 to 5% volumetric concentration of ethanol. The time of fire eextinguishment shows the minimum value at 3% contained of ethanol in water mist, and also the dynamic behavior to extinguish is more safety without fire expansion than that for pure water mist. The improvement of water mist extinguishment is mainly resulted in decreasing the mist diameter by adding small amount of ethanol.

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The fire spread route is strongly dependent on the distribution of combustible materials. This paper described the experimental results of flame spread tests along randomly distributed combustible cubes. Flame spread experiments conducted with changing porosity and ignition position. Flame spread probability at random ignition position is higher than that at corner ignition with same porosity. Burned area differed with a changing ignition position under the same test sample placement.

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The purpose of this study is to develop the compact auxiliary heater using tubular flame for home CHP (combined heat and power). The tubular flame is formed in a rotating flow field by injecting the air-fuel mixture tangentially into the cylindrical chamber. Combustion gas of the tubular flame has a high heat transfer coefficient due to the swirl flow. The coiled tube and the inserted tube installed at the center of the coiled tube are used as a heat exchanger. Combustion gas flows through the gap between in coiled tube and inserted tube. The thermal efficiency is 87% based on LHV. In this study, the heat transfer characteristics of the coiled tube is reported.

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The Purpose of our research is to improve the energy efficiency of multi split type air conditioning systems for buildings operated under low thermal load conditions. For this purpose, we develop an innovative energy-saving A/C controller that enables an optimum operation of A/C and the heat recovery VRV systems. By combining the COP data of A/Cs obtained by those tests and the field data measured in a real building, the annual energy consumption of the A/C system was estimated to examine the energy-saving effect of the new A/C controller. As a result of this estimation, it was ascertained that the new A/C controller could attain 50% higher annual average COP IN comparison with that of the conventional controller.

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A heat pump system using solar heating, radiation cooling and air-convective heat transfer, the Sol-Air Heat Pump system, SAHP, was newly developed. This SAHP unit was equipped on the roof of a building in Tokyo and its heating/cooling operational performances have been investigated under various weather conditions in a year. A thermo-dynamical analysis was carried out and compered with the measurements. The measurements of the heat outputs in both heating and cooling operations are in food accordance with the analytical results. The correlation between the measurements and the analysis of the coefficient of performance, COP, are also discussed.

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The ground source heat pump (GSHP) uses pipes which are buried in the ground to extract heat from the ground. This heat can be used to heat radiators, under-floor or warm air heating systems and hot water in an office room. The GSHP were adopted a closed loop and vertical borehole system. This paper describes an experimental result regarding an amount of transported heat and a coefficient of performance of the GSHP. The GSHP system will operate continuously during a month or more. The measuring accuracy of the amount of heat transported by the GSHP were evaluated and discussed.

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Numerical analysis of heat exchange rate of several types of vertical ground heat exchangers (GHEs) with different condition of inlet water temperatures, borehole depths, and tube configurations have been carried out. The GHE models were built and simulated by using a commercial CFD code, FLUENT. Heat exchange rates per unit borehole depth of the GHEs increase in the cooling mode and decrease in the heating mode of 3.4 W/m for U-tube, 5.7 W/m for double tube, and 3.3 W/m for multi-tube with increasing of 1 ℃ of the temperature difference between inlet water and ground. Also, increasing the borehole depth lowers temperature difference between circulated water and surrounding ground and then lowers the heat exchange with the ground. Furthermore, thermal interference between inlet and outlet tubes due to the tube configuration affects significantly to the heat exchange rate of the GHEs. Insulating the outlet tube and increasing the inlet tube diameter in the multi-tube GHE contributes to the increasing the GHE performance.

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From the view point of energy saving and environmental impacts, we have been studying Chemical heat pump (CHP) especially focusing on using calcium systems. The CaSO_4/Caso_4 1/2H_2O gas-solid reversible reaction is used to store at around 393K and release hot/cold heat. In this paper, we studied the energy efficiencies of CaSO_4 CHPs could be used for commercial for wider operating temperature ranges in appropriate heat source conditions.

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The present Study proposes to suspend lithium bromide fine crystal power in the solution for the lithium bromide/water absorption heat pump system. The effect of lithium bromide fine crystal slurry on the performance of the absorber was evaluated analytically by a theoretical model. The absorption performance was examined by a batch type of absorber connected to an evaporator set at constant water temperatures. The absorption amount of water vapor into the solution in the absorber was determined by the energy balance from the time behavior of solution temperature.

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The study analyzed an air-conditioning system for agricultural use. The system consists of a desiccant dehumidification unit and a heat pump to control temperature and humidity in greenhouses. A simulation tool ri predict the performance of the proposed system was developed, and the optimal system structure was found under the winder season condition.

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Control of the temperature and relative humidity in greenhouses is very important in the agricultural sector. This study proposed a combined heat pump and desiccant air conditioning system to control temperature and relative humidity in greenhouses. The performance of dehumidification in the desiccant and the influence of regeneration temperature were verified by experiment. It was found that the dehumidification performance improved when the regeneration temperature was high. It was found that desorption and adsorption ratio 2:1, achieved the largest dehumidification rate.

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This paper presents the development of thermal actuated micro-scissors. This micro-scissors consists of a single polymeric layer (SU-8), and was fabricated with conventional photolithography techniques. Whole size of micro-scissors device is 4.9mm square, and its blade length is 350 μm, and thickness is 100 μm. The micro-scissors were operated with thermal expansion of their beams resulting from IR laser heating. The experimental results demonstrate that thermal actuated micro-scissors can achieve a displacement for 9.5 〜 24 μm, by changing laser output. The micro-scissors also high repeatability, therefore they can be used for higher level of less-invasive therapies, for instance, single cell resection.

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The effect of channel geometry on the discharge pressure of valve-less micro-pump with a diffuser/nozzle shaped channel was investigated. The micro-pump channnels of various angles of 30, 60, 90 degree between main channel and connecting channel to the chamber with actuator were prepared. The measured discharge pressures were rearranged using dimensionless numbers as head coefficient y, and compared the frequency characteristics for various pump channels. As a result, higher head coefficient indicated for the angle of 30 degree which had higher junction loss from the chamber to the inlet channel.

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It is suggested that a steam injector (SI) is applied to heat pump systems to downscale them. Because SI has high heat transfer performance due to the direct contact condensation, and the feature to act as a static jet pump without any rotating power. Thus the objective of the present study is to investigate the heat transfer flow characteristics of an ultra micro steam injector (UMSI) whose throat diameter is 600 μm by the flow observation. As the results, the formation of water jet and the back stream in the mixing nozzle which are the operating characteristics of SI is confirmed.

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This paper reports a MENS based viscosity sennsor suitable for in-process measurement in industrial uses. The sensor is based on the vibrating viscometer. However, the vibrating body is unique dual spiral geometry. The viscosity of the liquid is obtained by curve fitting of the frequency response curve of the spirals. In the present study, we propose an improved chip holder having an electromagnet coil to drive a permanent magnet implanted in the vibrating body of the sensor. The frequency response curve obtained in the experiment shows a good agreement with the theoretical curve.

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Three-dimensional simultaneous measurements of the position of a rising microbubble, and of the velocity field surrounding it, are performed by micro-digital holographic velocimetry. The rising position of the microbubble and the many particles surrounding the microbubble can be reconstructed by a digital hologram. This technique has successfully been applied to the 3-D dynamics of a hydrogen microbubble, in a vertical water channel, that emanates from a platinum electrode by electrolysis. The velocity of the microbubble and the flow of particles surrounding the microbubble are simultaneously obtained.

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The electrostatic potential distribution at liquid-liquid interface in a microchannel was directly measured by nano color imaging technique using two kind of fluorescent dyes and the evanescent wave. A T-shaped microchannel for an aqueous solution was attached to an I-shaped microchannel for an oil phase in order to from the liquid-liquid interface between two immiscible fluids. Two kinds of aqueous solutions at different Na^+concentrations were mixed in the T-shaped microchannel for investigating the effect of Na^+ motion on formation of electrostatic potential at the interface. The calibration curve expressing the relationship between the fluorescent intensity ratio and the electrostatic potential was prepared to convert the fluorescent intensity image into the electrostatic potential distribution. Moreover, the Na^+ concentration distribution near the interface was also measured by microscale laser induced fluorescence which comprised of a confocal microscope and an ion indicator. Formation mechanism of electrostatic potential will be examined by comparing the Na^+ concentration distribution with the electrostatic potential distribution.

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For investigations of microscale thermo-fluid structure in gas flow, a non-intrysive sensing technique was proposed using coherent anti-stokes Raman scattering (CARS). This technique enables us to obtain the informations from molecule with high spatial and temporal resolutions by a femtosecond pulse laser. The scattered light of vibrationally resonant gas and nonresonant gas was measured for CO_2 and N_2 respectively. Calculating the difference between high intensity from each gas realizes detecting a specific gas flow.

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The effect of the wall surface roughness on the zeta potential in a microchannel flow was investigated by micron-resolution particle image velocimetry combined with a confocal scanner (hereinafter called confocal micro-PIV). The nanoscale wall surface roughness of microchannel was modified by a cryogenic micromachining system that enables the formation of grooves in elastic materials such as polymers by applying cryogenic cooling. polymers change from a rubbery state to a glassy state below the glass transition temperature; for polydimethylsiloxane (PDMS), this transition occurs at -123 degrees centigrade. Prior to a set of experiments, the electrophoretic velocity of 1 micron diameter fluorescent particles at different pH was measured by current monitoring. The particle mobility near the PDMS wall at different wall roughness was measured by confocal micro-PIV. The electroosmotic velocity was calculated subtracting electrophoretic velocity from particle velocity. Finally the zata potential was obtained by the Helmholtz-Smoluchowski equation.

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A pre-combustion CCS system burns hydrogen or hydrogen rich gas in the combustor. Combustion simulation can give useful knowledge to design combustor. Fundamental experiments are necessary to provide data for a hydrogen combustion model expressing instabilities. This is essential because most flame instabilities are triggered by flow rate oscillations. a photomultiplier tube (PMT) with a filter of 308 nm is employed to observe the acoustic effects on the light emission from the OH radicals in the flame. Also, a Constant Temperature Anemometer (CTA) is employed to measure the flow rate oscillations. An apparatus consisting of a burner and a mixing chamber has been constrycted for this experiment. A speaker inside the mixing chamber is controlled by a fonction generator, which controls its frequency and amplitude. As the speaker frequency increases with a reasonably constant deviation of the CTA, the deviation of the PMT voltage decreases.

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In this study, a turbulent jet flame is studied using simultaneous high speed laser diagnostics. Information from CH and OH PLIF, as well as stereoscopic PIV was obtained on a single plane at a frequensy of 10 kHz. Analysis of the OH PLIF and velocity data using Extended POD, as well as OH LIF data using DMD, showed that in this particular flame the average of the signal is by far the main component of the signal, with no outstanding strong feature. Such diagnostics and post-processing methods open new perspectives on the experimental study of flow-flame interactions and flame dynamics.

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Flame front area of turbulent flame is considered to be the dominant factor to turbulent burning velocity. The flame surface density is an important parameter and is considered in turbulent combustion models. The flame surface density of spherically propagating premixed turbulent flame was experimentally obtained by Mie scattered laser tomography technique. The peak value of flame surface density decreased as flame propagated at the same innitial mixture pressure. The values of flame surface density at elevated pressures were larger than that ato 0.10 MPa Both large and small scale wrinkles may affect the value of flame surface density.

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Three-dimensional direct numerical simulation of hydrogen-air turbulent premixed flame in a larger constant volume vessel at relatively high Reynolds number has been conducted considering the detailed kinetic mechanism to clarify effects of pressure increase on dynamic characteristics of turbulent premixes flame. The DNS results in the larger volume vessel of this study and in a smaller volume vessel of our previous study have been compared to reveal effects of the vessel's size. The mean pressure in both the vessel reaches about 3 atm at the end of rapid combustion. Heat release rate of each flame element is augmented since the pressure increase makes flame thickness thin. The local pressure rise due to dilatation also enhances turbulence and finer scale vortices appear, which makes flame surface more complicated and results in increase of the flame surface area. The shape of the flame front becomes complicated and the meximum value becomes higher due to increase in pressure. By identifying flame elements in turbulence, the statistical characteristics are also discussed quantitatively.

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