Viscous flows in a concentric annulus with rotating inner cylinder is characterized by Taylor-Couette flow. When the annular gap is formed by the inner conical cylinder submerging in a cylindrical vessel, the effect of imbalance of centrifugal force dominates the flow field as well, while the basic flow, rather than the Taylor vortex, having 3D structure appeared even at rather high angular velocity. This paper describes convection patterns and their transitions appeared in the annular gap confined by conical rotor and cylindrical vessel under non-isothermal operations.

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The purpose of this study is enhancement of natural convective heat transfer from the vertical plate using some baffles and periodic oscillation. Particularly the effects of baffle height and baffle width are investigated by numerical simulation in this paper. The oscillated velocity is almost half flow velocity of vertical flat plate with no oscillation to reduce the effect of forced convection. The results show that spatially and temporally averaged Nusselt number became larger than that of stationary flat plate but smaller than that of oscillatory flat plate. This results show that baffle is not good application for enhancement of heat transfer.

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In this paper, the thermal convection field and its resonance phenomena in a square cavity with sinusoidal heat-flux vibration were numerically examined at Pr=0.71, Ra=10^6. When the amplitude of the vibration a is less than unity, i.e. α<1.0, the field has the local maximum of relative amplitude of midplane Nusselt number at a critical angular frequency ω_c=350 in accord with that of the internal gravity wave. In contrast, for a>1.0, we found that the thermal convection field exhibits a nonlinear response to the vibration. ω_c is changed linearly with α, and we observed the nonlinear resonance phenomena which differs from the one induced by the wave.

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The authors conduct numerical investigations about the three-dimensional thermal convection in a cubic cavity heated below in the gravitational field. Frequency responses are analyzed numerically concerning global quantities such as spatially-averaged kinetic energy and so on. We assume incompressible fluid with a constant Prandtl number Pr=7.1 (water). Tested Rayleigh number Ra is varied from 5.0×10^3 to 8.0×10^4, ω is varied from 10 to 1000. For Ra=1.0×10^4, η is varied from 0.1 to 15. For Ra=4.0×10^4 and 6.0×10^4, the frequency response is investigated for η=0.1. As a result, the authors find out the existence of η that minimizes the maximum frequency response for Ra=1.0×10^4, Pr=7.1.

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The double diffusive natural convection arises owing to the rate difference between thermal and solutal diffusions in a fluid containing temperature and concentration gradients. The double diffusive layered convection due to thermal plume in linear concentration gradient system was numerically studied at the Prandtl number Pr=6, the Rayleigh number Ra=10^7 or 10^8, the Lewis number Le=100, and the buoyancy ratio N=1.5. Thermal plumes occur from the heat source on the bottom but stop the ascending owing to the concentration gradient. Then the plumes develop to the primary convection layer with time. The temperature in the primary convection layer increases with time, and second thermal plumes occur on the primary hot convection layer. Finally the second thermal plumes develop a secondary convection layer.

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Solar pond is a storage technology of solar heat. The double diffusive phenomena in solar pond were numerically studied for a two-layer system which consists of a pure water (upper layer) and an aqueous solution (lower layer) with the heating from the entire bottom at the Prandtl number Pr=6, the Lewis number Le=100, the Rayleigh number Ra=10^7, the buoyancy ratio N=2 and the volume of a lower layer V_<low>=20 or 50%. The convection in a lower layer was circulating flows at V_<low>=20% and ascending plumes at V_<low>=50%.

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When a turbulent boundary layer approaches a symmetric bluff-body, the body-generated adverse-pressure gradient precipitates a separation process that forces the impinging boundary layer vorticity to reorganize into a horseshoe vortex. Endwall heat transfer is influenced by the presence of horseshoe vortex. This paper shows the result of experimental and numerical study about the horseshoe vortex and heat transfer in the leading-edge endwall region. Naphthalene sublimation method was used to measure the detail local heat transfer coefficient distribution on the endwall. The v2f model resulted in good agreement of the local heat transfer coefficient distributions between experiments and numerical analysis.

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The multiple jets were accompanied with the spent flow and its directions were also very important to affect the flow and heat transfer. We shows the effect of the spent flow on heat transfer characteristics of multiple jets impinged to confined rectangular duct setting the side plate by change its position from jets origin. The flow and heat transfer coefficients were measured by means of oil-method and infrared image technique, respectively. It was found that the heat transfer was characterized with the spent flow and vortex streak formed at the comer surrounded by the side and the impingement plates.

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The turbulent flow drag and heat transfer coefficients can be reduced dramatically by adding small amounts of drag-reducing additive to flowing water. The surfactant solutions including rod-like and cord-like micelles shows the Non-Newton characteristics and the flow drag reduction effect in a turbulent pipe flow. In this study, TOHO-DRC6B (main component: Oleyl Dihydoroxy Ethyl Amine Oxide, ODEAO, non-ionic surfactant) was selected as the flow drag reduction additive. ODEAO is added to propylene glycol (PG) solution. From the flow resistance and heat transfer experiment results, the flow resistance and heat transfer coefficient of the PG solution with ODEAO in straight circle pipe were markedly reduced as compared with that of propylene glycol solution as solvents.

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Two-dimensional compressible momentum and energy equations are solved to obtain the heat transfer characteristics of gaseous flows in a microtube with constant heat flux whose value is positive or negative. The numerical methodology is based on the Arbitrary-Lagrangian-Eulerian (ALE) method. The computations are performed for tubes with constant heat flux ranging from -10^4 to 10^4 Wm^<-2>. The tube diameter ranges from 10 to 100μm and the aspect ratio of the length to diameter is 200. The stagnation pressure, p_<stg> is chosen in such away that the Mach number at the exit ranges from 0.1 to 0.7. The outlet pressure is fixed at the atmosphere. The wall and bulk temperatures in micro-tubes with positive heat flux are compared with those of negative heat flux case and also compared with those of the incompressible flow in a conventional sized tube. In the case of fast flow, temperature profiles normalized by heat flux have different trends whether heat flux is positive or negative. A correlation for the prediction of the wall temperature of the gaseous flow in the micro-tube is proposed.

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Numerical analysis and experiments on convective heat transfer from a rotating disk with fins, which are arranged along radial direction, are performed and the results are compared to realize the designing of the ECB retarder using not only experiment but also analysis. The results show that the heat transfer coefficients and the flow patterns obtained by the analysis and the experiments agree each other considerably. On the other hand, there are some differences between the results of analysis and those of experiments, for example, the tendency of the radial distribution of heat transfer coefficients. The investigation of the cause of different results on the velocity vectors around the inner edge of the fin under some conditions is necessary to diminish the discrepancy of the results between the numerical analysis and the experiments.

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In CO_2 ocean sequestartion with a moving ship, oscillation of CO_2 releasing pipe by vortex induced vibration (VIV) is potential source to increase hydraulic resistance and possibly causes mechanical damage on the pipe. Wake flow formed behind the releasing pipe is to be a highly turbulent flow over critical Reynolds number. It is important to fundamentally elucidate generating mechanism of VIV around a cylinder. In this study, we investigated VIV behaviors and flow structure behind a cylinder by measuring two-dimensional velocity field with time-series particle image velocimetry (PIV). It was confirmed that oscillation of the cylinder was amplified in accordance with periodical vortex sheddling.

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Direct numerical simulation was performed for fully developed turbulent channel flow with lateral (spanwise) non-uniformity of mean temperature (STG) and the same flow but having uniformly heated wall (UHF). For both, two kinds of wall boundary condition were simulated ; steadily constant temperature (iso-thermal) and temporarily constant flux (iso-flux). Through simulations, the Reynolds number based on channel half width and friction velocity was kept at 150, and the Prandtl number at 0.71. Forth order finite differencing was adopted, and 64×127×26 grid points were allocated for computational domain. According to numerical results, regardless of wall boundary condition, the eddy diffusivity ratio, ε_<hz>/ε_<hy>, is found to be nearly equal to the Reynolds normal stress ratio, <w^2>^^^/<v^2>^^^, over the channel width excluding thin layer close to the wall (y^+<1).

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Direct numerical simulation (DNS) of supercritical CO_2 turbulent channel flow is performed to investigate the heat transfer mechanism of supercritical fluid. In the present DNS, full compressible Navier-Stokes equations and Peng-Robison state equation are used. Due to the effects of the mean density variation in wall normal direction, mean velocity in the cooling region becomes high compared with that in the heating region. The mean width between high-and low-speed streaks near the wall decreases in the cooling region, which means that turbulence in cooling region is enhanced and lots of fine scale eddies are created due to the local high Reynolds number effects. In the cooling region, Nusselt number becomes large due to high thermal conductivity and low kinematic viscosity which cause modification of turbulence structure.

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This paper presents reconstruction of turbulence heat transfer model using direct numerical simulation (DNS) data of thermal boundary layer with buoyancy. Since a buoyancy-affected boundary layer is often encountered in an urban environmental space where stable and/or unstable stratification exists, predicting a buoyancy-affected boundary layer is very important to improve the urban environment. On the other hand, reconstruction method using DNS data of a turbulence model, which is powerful tool for the prediction of heat transfer, has been reported by many researchers. A number of DNS data of channel flows are supplied, but DNS data of boundary layer have been hardly provided. Thus, in order to create DNS data of a buoyancy-affected boundary layer, we have carried out spatially-developing DNS of stratified stable/unstable boundary layer. The existing turbulence models are evaluated using the present DNS data, and an improvement points of turbulence model are found out.

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Direct numerical simulation of turbulent heat transfer in a channel flow through high spatial resolution has been carried out for Re_τ=180, which is based on the friction velocity and the channel half width. The configuration is a fully developed turbulent channel flow with uniform heat flux heated from both walls. Molecular Prandtl numbers are set to be 0.71, 1.0, 2.0 and 10.0. The Prandtl number effect on the turbulence quantities such as the turbulent Prandtl number and the cross-correlation between velocity and scalar fluctuations are examined. Moreover, the resulting one-dimensional pre-multiplied energy spectra of temperature fluctuations at large wavenumbers are investigated to confirm the accuracy of the calculation.

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Single-wall carbon nanotubes (SWNTs) were synthesized by laser vaporized catalytic chemical vapor deposition, which is a combination of laser vaporization and alcohol-CCVD technique. Catalyst particles were prepared by pulsed laser vaporization of a metal rod and ethanol vapor were employed as carbon source. The diameter distributions of the synthesized SWNTs were investigated by Raman spectroscopy. In addition to this technique, the conventional laser oven technique was also studied to synthesize SWNTs. The diameter distribution of SWNTs, which is synthesized by laser oven technique, is in narrower than that synthesized by laser vaporization catalytic CVD.

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Co and Mo are often used as catalysts for the catalytic chemical vapor deposition (CCVD) synthesis of single-walled carbon nanotubes (SWNTs) on a substrate. Although the relation between activation processes and SWNT growing behavior is still not fully understood, these catalysts should be activated by heating in hydrogen before the CCVD. In this study, the relation was clarified in the SWNT synthesis from carbon monoxide (COCCVD) using a Co/Mo bifunctional catalyst.

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Vertically aligned single-walled carbon nanotubes (VA-SWNTs) are a new material expected to be used in various applications, such as field emission displays, or optical devices. We have developed the alcohol catalytic chemical vapor deposition (ACCVD) method to produce high-purity VA-SWNT films from alcohol. However, ACCVD growth control is not well-established because the SWNT synthesis mechanism has not yet been clarified. In this research, we attempt to better understand the SWNT growth mechanism, with the aim of improving the uniformity in length, diameter and chirality of the VA-SWNT films.

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Molecular dynamics simulation was adopted for 1-propanol and 2-propanol with a hydroxylated silicon dioxide (SiO_2) surface. Large clusters of 1-or 2-propanol, which were induced by the hydroxylated surface, were observed. These results are similar to that for ethanol in the previous our simulations. The mean size of the cluster is independent of the molecular structure. However, the anisotropic shape along the axis normal to the surface for 2-propanol was larger than that for 1-propanol. The results for 1-propanol is similar to that for ethanol.

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A micelle is the self-assembly of surfactant molecules formed in surfactant aqueous solution. The micelle has various forms such as a threadlike, spherical, discoid, and bilayer. Particularly, the threadlike micelle has the great possibility of the application in the industry, utilizing the uniqueness in its formation. However, an overall understanding of the formation dynamics of the threadlike micelle has not been accomplished, because of the so-called 'mesoscopic problem' in dynamics. In this paper to clarify the multiscale dynamics in the threadlike micelles we adopted the Dissipative Particle Dynamics (DPD) simulations. Moreover, the shear stress was put on a similar system, and it comnpared it without shear stress.

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In micro-fabricated electric device, non-equilibrium state might be appeared in metal and/or semiconductor that compose the device. In such a situation, the device performance estimation by the macroscopic transport equations that assume quasi-equilibrium distribution is difficult. Against the background of this difficulty, we are developing a numerical simulation based on Boltzmann transfer equation (BTE), which can analyze thermal and electric phenomena even when the state is far from equilibrium. In this paper, we show the BTE formulation and its application to the electric field problem in metallic plate. As numerical calculation result, we obtained the maximum of electric charge density at both boundary and the shifted-distribution function, which agree with physical intuition.

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We propose a novel technique of molecular dynamics simulation to evaluate the relaxation time of phonons in solids for investigation of solid heat conductivity. The method is to observe relaxation behavior of the power spectrum of atomic velocities after energetically stimulating modes in a specific frequency region. The transient entropy S(t) is defined with the power spectrum based on non-equilibrium statistical mechanics. The obtained S(t) was found to be well fitted to a single exponential function, from which the frequency-dependent relaxation time can be evaluated.

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The quantum molecular dynamics was applied to a simple system composed of an electron, potassium ions and xenon atoms in order to investigate an energy transfer process to an electron in surface collision process of an ion. A time dependent Schrodinger equation for an electron was solved by the splitting operator method and Newton's equations for classical particles were solved by the molecular dynamics method. With the increase of interaction between an electron and xenon atoms the electronic energy during collision process increased. Electronic trajectories during surface collision process of the ion were much dependent on magnitudes of interaction between the electron and the classical particles.

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This paper describes a fundamental study for UVP measurement of boiling two-phase flow. The ultrasonic sensor for transmitting and receiving ultrasonic pulse decreases the sensitivity with temperature rise, because the piezoelectric elements of the sensor loses the piezoelectric effect over Curie temperature. So the high-temperature ultrasonic sensor is required for boiling two-phase flow measurement. In this study, the ultrasonic sensor with allowable temperature limit of 120 degrees Celsius was produced by using the 1-3 composite oscillator, which has high sensitivity and has been used widely for fluid flow measurement. Using this ultrasonic sensor, the rising velocity profiles of vapor bubbles generated by a heater were measured by UVP monitor.

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In this study, our purpose is to obtain instantaneous and mean velocity profiles in a Taylor-Couette vortex flow (TVF) by using a pulser receiver device based on a ultrasonic generator. The experiment was carried out with a small aspect ratio where the Ekman boundary layer was not neglected. The device has a radial ratio of 0.375, aspect ratio of 3 and the gap length between the inner and outer cylinders of 25mm. As the result, the velocity profiles and their absolute values were in good agreement with the ones obtained by the Ultrasonic velocity profiler (UVP). This measurement system was applied to the solid-liquid phase flow experimentally, and well measured even in the opaque dilute solution.

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Measurement of an oil circulation ratio (OCR) in refrigerating cycles is important for evaluating the reliability of a compressor and the performance of heat exchangers. The OCR is typically measured by a sampling method, but the method consumes time and can not measures the transient change of the OCR. On the other hand, the OCR measurement by the sound speed of refrigerant/oil mixture is easily done in real-time. In this study, the ultrasonic sound speed sensor was developed, and the sound speed of the refrigerant/oil mixture was measured. Moreover, the correlation between the sound speed and the oil concentration is clarified.

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A distribution-measurement system with 8 channel transceivers and multi-surface-coils of 1.3mm outside diameter for monitoring water content distribution in polymer electrolyte membrane (PEM) was developed. Using the CPMG method, water content in PEM can be obtained from echo-signal intensity and T_2(CPMG) relaxation time. MEA (Membrane Electrode Assembly) was put in the cell controlled at the cell temperature of 75℃ and the vapor concentration of 0.14 kg/m^3 in N_2 gas. Time-dependence changes of echo-signal intensity of MEA under water electrolysis condition were obtained by the multi-surface-coils on the anode and cathode electrodes.

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To show three dimensional flow structures is useful and effective when we treat with complicated flows such as bubble jets. A three-dimensional particle tracking velocimetry (3D PTV) is one solution, but has unknown factors. In the present study, we conduct the simultaneous measurements of 3D PTV with an ultrasonic velocity profiler (UVP) using the common tracer particles. The simultaneous measurements have other applicable possibilities, as well as accuracy check of 3D PTV. We tested four conditions I-IV of tracer particles. As a result, UVP is not applicable for small number of the tracer particles. On the other hand, 3D PTV is not applicable for large number of the tracer particles. We have found the optimum condition for both measurements, and confirm the accuracy of measurements.

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Ultrasonic velocity profiler (UVP) is applied to measurement of water flow under the bottom surface of a ship. The aim of this study is to establish the practical utilization of UVP system for large ships whose power loss is generally dominated by frictional drag. As the first phase, the measurement performance is evaluated for capturing the turbulent boundary layer of a small model ship using a new ultrasonic transducer. The experiments are performed for a towing ship in a shallow pond and also for a freely supported ship in an open channel. A wedge type of ultrasonic transducer is designed so that the flow is undisturbed with it. The velocity profile including the boundary layer is successfully obtained after suitable post-processing is implemented to remove erroneous data caused by multiple reflections. Data analysis is also made to estimate the skin friction from the profiles measured.

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Thermal efficiency of polymer electrolyte fuel cell extremely depends on a water distribution in Gas Diffusion Layer (GDL). Fuel cell model was prepared in order to investigate the water distribution in GDL by ultrasonic techniques. Acoustic impedance of GDL, which is porous plate of carbon, was estimated as bulk model to know approximated value of reflection ratio of ultrasonic echo. We attempted to measure an instantaneous ultrasonic echo that changes by the quantity of the water to detect existing water in GDL. And we focused on the phase delay and the amplitude change of the ultrasonic echo and analyzed the waveform.

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Ultrasonic Velocity Profile (UVP) method is a measuring method with the velocity component along the ultrasonic beam. It is useful method as velocity profile measurement of an opaque fluid like a magnetic fluid. When we apply the ultrasonic method to some fluids, we have to obtain the ultrasonic propagation velocity in those fluids. However, ultrasonic propagation velocity in magnetic fluid has not been investigated in detail. In this present paper, we measured the ultrasonic propagation velocity in a magnetic fluid precisely and analyzed the influence of the chain like cluster under magnetic field on the ultrasonic propagation velocity. On the basis of these results, oscillating pipe flow of a magnetic fluid was investigated experimentally by the UVP method.

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The ice nucleation of water atomized by supersonic air streams was investigated through the experiment with a phase Doppler particle analyzer and the unsteady thermal conductive analysis. The experimental results show that the average diameter and velocity of the water droplets are 8μm and 484m/s respectively at the nozzle exit. The thermal conductive analyses indicate that the water droplet which diameter is smaller than 5μm freezes inside the nozzle regardless the relative velocity for the air streams.

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Solidification of liquid-fine particle suspension in an ultrasonic standing wave has been studied. In this paper, we propose a new manufacture method of composite materials by the following process: first, an array of solid particles in the melt is produced by radiation force of ultrasound, and next the matrix is fixed by the solidification. By freezing experiments using water-alumina/silica particle suspensions, it was found that the liquid region consists of a region, in which particles suspended in water were trapped and agglomerated at every half wavelength in the standing-wave field, and a transitional layer. In the transitional layer, some of particles were swept from freezing front and accumulated with air bubbles. The micro-behavior in this place controls the appearance of lamellar structure.

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This study deals with thermal hydraulic characteristics of a paraffin emulsion, in which a paraffin wax with a melting point of 72℃ and latent heat of 222kJ/kg was used as phase change material. Pressure loss and heat transfer coefficient in a cooling process were measured for a horizontal copper tube with inner diameter of 4mm. As a result, it was shown that heat transfer performance of paraffin emulsion was lower than that of water, because of its high viscosity and a delay in phase change of paraffin wax. Paraffin emulsion at the exit of heating section was in a thermal non-equilibrium condition, and recovery of temperature after mixing was observed.

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This paper describes the effect of shape parameters on the flow resistance of perforated plates used in electronic equipment. In order to demonstrate the influence of hole shape on the flow resistance of perforated plates, measurement of 16 perforated plates and analysis of the results were conducted using the Design of Experiments (DoE) method. In the range of levels of DoE analysis assumed for electronic equipment, it was found that hole shape has little effect on flow resistance.

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The results of electro-thermal analysis is strongly depended on the mesh size. However the appropriate mesh size or mesh zoning method were not reported. In the present work, we propose the mesh zoning method for electro-thermal analysis of Si MOSFET, which is derived from the theory of semiconductor physics. The calculation results show the results with zoned mesh have a good agreement with that with fine mesh. Mesh number can be reduced by using zoning method. As a result, our mesh zoning method can reduce the calculation time by at least 30 times.

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Performance of semiconductor devices has strong temperature dependence. The cooling technology is a key technology for semiconductor devices. In this study, we have developed water cooled heat sinks for a laser diode bar. Experimental study was conducted to investigate the effect of shape of a cooling channel. Cooling channel has contracting part and bending part into upward diode and expanding part into downward diode. Water flow was impinging to a wall under the diode bar. Thermal resistance of heat sink is 0.35℃/W without increasing pressure drop.

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The thermal resistance of cooling device using forced oscillatory flow was examined experimentally. In addition, a numerical simulation using the thermal network method was carried out to investigate the influence of the frequency and the tidal displacement of the oscillatory flow and the channel pattern on the thermal resistance. The heat spreader is a thin copper plate with the thickness of 1.2mm that contains a 0.8mm square channel. The experimental results indicated that the surface temperature of the heat spreader is decreased by the forced oscillatory flow in the heat spreader.

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Heat transport characteristics of pulsating heat pipe were investigated by using 12 turn copper tubes with water as the working fluid. Wall temperature fluctuations were measured at 15 points on adjacent 3 tubes. It was found that the oscillating behavior differs depending on the inclination angle in the case of relatively small heat loads (less than 500W), in which the oscillation occurs intermittently. In the case of large heat loads (500W-1000W) the oscillation characteristics were almost independent of inclination angle, and the frequency increases with the heat load. Other detailed features of temperature fluctuations, such as auto-correlation functions and relationships between adjacent tubes, were examined.

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It is vital to calculate the flow rate when a cooling fan is applied to a cooling design of an electronic equipment. Usually, the flow rate is calculated by comparing a P-Q curve with a static pressure difference between front and back side of the fan. However, it is difficult to determine which location should be selected as the pressure evaluation point in a densely packed condition since the pressure field is not uniform. Thus, the accurate flow rate can not be determined through the conventional method. The objective of this study is to develop a cooling fan model that can be effectively employed for cooling design of electronic equipment.

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For a practical thermal design of the electronic equipment, an efficient thermal design technique is needed. There is a Build-Up Approach concept in one of the convincing technique. In this study, a CFD and a thermal network method have been combined toward the BUA. Heat and fluid flow in a card-type device were simulated with the CFD at first. The thermal network method is applied to the parametric survey with the aim of obtaining design guides. This approach makes design time shorter. The results of experiments, the CFD, and the thermal network method were compared and the application possibility of this approach was examined.

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To attain high cooling performance in the electronic equipment like personal computers with high heat fluxes, an interstitial material (generally, some kind of grease) is often introduced between a heat sink and a heat source. Concerning this problem, the authors have been conducting basic experiments. However, in those experiments, there have been observed fairly large differences between the measured thermal resistances and those estimated by using the grease thickness and the thermal conductivity put on a catalogue. Then, in the present study, a simple method for thermal conductivity measurement of a grease has been tried, where the thickness of the grease layer has been changed from about 0.75, 1.75 and to 2.70mm.

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In recent years, the recording speed of optical disc drives is increasing. Along with this, the power consumption of laser diodes in optical pickups is increasing. Although, reliability of laser diodes depends on temperature, we need to design the laser diode to operate at appropriate temperature. Therefore, precise prediction of laser diode temperature by thermal analysis has become important. We measured the distribution of the heat transfer coefficient around an optical pickup for various rotating speeds of an optical disc, and applied this to thermal analysis. We confirmed that the temperature of a laser diode can be predicted with high accuracy using this method.

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Recently, data transfer rates of optical disc drives have been dramatically increasing. To obtain the high data transfer rates, disc rotation speed and laser power also need to be increased. Therefore, to develop the next generation optical disc drives effectively, enhanced cooling system of the optical pick-up unit which includes the laser diode is indispensable. The cooling performance of the pick-up unit is directly influenced by the inside air-flow induced by the disc rotation. To maximize the effect of the air-flow around the pick-up unit, we applied the combination of PIV (Particle Image Velocimetry) and CFD (Computational Fluid Dynamics) simulation. It was made clear that making the opening near the pick-up unit could increase the cooling performance of the optical disc drive very effectively.

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This paper describes cooling performance for panels in liquid crystal projector. We divide a light from the lamp into three parts. Those are R (red), G (green) and B (blue). We have three optical components in R, G and B, severally. We consider the three optical components as the parallel plates. Both the pressure drops between the inlet and the exit in the parallel plates, and the mean heat transfer coefficients between the parallel plates are calculated. The gap between the parallel plates is optimized once we use a fan in the liquid crystal projector. In this paper, the optimum gap is 1.1-1.2mm. The temperatures in the three optical components for R, G and B are predicted.

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Feasibility study of liquid cooling systems for controllers of disk array systems, which generates high-density heat in the chassis, is conducted. Low-height prototype radiator suitable for narrow channels is developed, and its thermal performance is evaluated. The prototype radiator is possible to dissipate about 180W at water flow rate of 300mL/min, frontal air velocity of 2m/s and temperature difference of 35 degree. Then the cooling performance of prototype liquid cooling system using the radiator is evaluated. Prototype liquid cooling system using brain frozen at -20 degree Celsius as a working liquid is able to cool controllers of about 150W heat generation, at frontal air velocity of 2.5m/s and ambient temperature of 35 degree Celsius. It is almost double the cooling performance that obtained by conventional forced air-cooling.

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Steam heating is a highly effective system for which need no power and which use the latent heat. In this paper, the performance of steam heating was studied when the heat pump was used as a heat source. It was confirmed that the combination of the heat pump and steam heating was working effectively, and COP could be 1.79 for heat source temperature of 16℃ and 2.73 for 24℃.

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A numerical simulation of an air-conditioning system using R134a instead of R22 was carried out. The numerical model of air-conditioning system consists of constant rotational speed compressor, condenser, evaporator, and capillary tube. The model geometry was determined from actual air-conditioner designed for R22. With this model, operating cycle with R22 and R134a were calculated and the performances were compared. When operating with R134a, calculation result indicates approximately 84 percent heat exchange and even higher COP in comparison with the case of R22. Performance prediction of refrigerant substitution for various designs of air-conditioning systems will be possible with this model.

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From the view points of energy saving and environmental impact, we have been studying Chemical heat pumps (CHP) especially focusing on using calcium systems. The CaO/H_2O/Ca(OH)_2 gas-solid reversible hydration/dehydration reaction is used to store and release hot/cold heat. In this study, we propose novel Cold Storage Vehicles using waste heat such as exhaust heat from the engine for energy source of the chemical heat storage/pump. It is shown that the chemical heat pump can be used for high-density heat storage of the waste heat and used for cooling and heating the vehicle space.

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