The methods to obtain the extinction coefficient and the scattering phase function are studied to solve radiative transmission through packed spheres by a continuous model. The validity of the methods is shown by comparing the results with the ones of direct Monte Carlo simulation. To obtain an effective extinction coefficient, a cell model which represents the extinction in a cell composed of a real-sized sphere and its surrounding volume should be used. To obtain an effective scattering phase function, non uniform radiation incidence to the surface of each sphere should be considered instead of using uniform incidence, and the non-uniform incidence onto each sphere surface can be obtained by considering that a real-sized sphere is set in a radiation field whose intensity from the entrance to the exit of the bed of the packed spheres.

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The temperature measurement accuracy of N₂ Q-branch CARS thermometry below 1000K has been improved by improving the spectral resolution of the detection system. The total spectral resolution was improved from 1.3cm^-1 to 0.6cm^-1 by the dispersion magnification (X3.6), which was done by adding a magnifier between a monochromator and an optical multichannel detector. An accuracy of temperature measurement in the temperature range of 300-800 K for pressures of 0.1-3.0MPa has been greatly improved from ±100K, in the case without the magnifier, to ±40K. The method reported in this paper has a potential advantage for practical use because of its convenience.

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This paper deals with an estimation method for the radiative properties of a fibrous medium taking account of the fiber orientation. In a case when the complex refractive index of the fiber material is known, a formulation for deriving the radiative properties, such as the extinction and scattering coefficients and scattering phase function, of the medium is described. In the other case, when the complex refractive index is unknown, an estimation method for the scattering phase function of the medium is described. In the method for the phase function, the radiation scattered by a single fiber which is taken out of the fibrous medium is measured and the phase function is derived from the measurement results by using the above formulation. The phase function for a slab with fiberglass randomly oriented in a plane was estimated by the present method. The radiation transfer in the slab, calculated using the phase function of the slab, is in good agreement with the transfer measured by an experiment.

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This paper deals with an estimation method of complex refractive index (CRI) of a fiber material. The intensity distribution of scattered light from a single fiiber has been measured for a perpendicular incident beam of light. Comparison of the experimental data with the computed ones based on the model of an infinitely long circular cylinder yields the CRI of the fiber material. Two kinds of fibers such as fused silica and tungsten were studied in this paper. The CRIs estimated in this study are 1.46-0.00·i for fused silica and 0.85-1.05·i for tungsten at the wavelength of 632.8nm. The estimated value of CRI for the fused silica is good agreement with the earlier one.

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For the purpose of obtaining the essential information of scaling in heat exchangers, microscopic observations were made for CaCO₃ deposition from a flowing solution onto initially clean heat-transfer surfaces. The growing rates of CaCO₃ crystals were measured by changing Reynolds number and supersaturation degree of the bulk solution, material and temperature of the heat-transfer surface. The growing rate was found to be relatively well correlated with the supersaturation degrees of the solution adjacent to the surface, deduced from the equilibrium relationship between the species in the carbonic solution. The nucleation rate was also estimated by measuring the change of the cumulative number density of deposited crystals against time. The crystals were formed on the surface with a constant nucleation rate over time, but the factors which dominate the nucleation rate could not be determined.

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Electric load levelling is one of the urgent requirements for the utility power industries in Japan. As a solution to this requirement, the intensive heat storage system utilizing surplus power during off-peak hours at nighttime was chosen for heating rooms and water supply in buildings, such as hotels and hospitals. This paper describes the conceptual study of a sensible heat storage system with solid storage material and its thermal characteristics. The system was assumed to be composed of a storage core of refractory bricks, an electric heater, a steam generator, and a fan for the recirculation of air to transport heat among these components. It was found through analysis that the lower air velocity, the narrower air passage in the core, and the thinner brick resulted in the increase of the amount of heat storage for a given volume of the core.

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Electric load levelling is one of the urgent requirements for the utility power industries in Japan. As a solution to this requirement, the intensive heat storage system utilizing surplus power during off-peak hours at nighttime was chosen for heating rooms and water supply in buildings, such as hotels and hospitals. This paper describes the system construction and the comparison of the analysis with the experiment on the 2300MJ solid material sensible heat storage system. The analysis considering heat loss predicted the variations of the air and brick temperatures in good accuracy in both charge and discharge processes. The effectiveness of the storage material is also discussed.

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The metalized slurry fuels are expected to enhance the combustion efficiency and the specific thrust of ramjet and scramjet engines. On the other hand, the disintegration mechanism of slurry fuel seems to differ from that of single-phase liquid such as water. It is expected that slurry fuel breaks up less readily than does single-phase liquid due to its high viscosity. This study aims to clarify the disintegration mechanism and spray characteristics of slurry fuels in high-speed air flow. In this report, the empirical equations of penetration and jet width were deduced. According to the empirical equations, the penetration and jet width of the aluminum-water slurry are larger than those of water under the same conditions. Furthermore, break-up locations of the aluminum-water slurry jet and water jet were measured. Consequently, by the above results, it was clarified the difficulty of disintegration for slurry jet attributes to the stability of the slurry jet due to its high viscosity.

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This report proposes the use of an optical probe to observe the particle behavior related to the rate of heat transfer in the freeboard region, and discusses the relationship between the heat transfer rate and the particle behavior in the expanded bed. This probe has two rods; one is a light-emitting diode (LED) used as a light source, and the other is a photocell. Measurements were carried out for a variety of optical probe locations and superficial gas velocities. The optical method for observing the particle behavior seems remarkably useful. It seems that the particle activity is dependent not only on the superficial gas velocity but also on the tube arrangement.

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The air blast atomizer has been widely used in combustors, for instance, spark ignition engines, gas turbines, rocket engines and industrial furnaces, because of its high performance and simple structure. The spray characteristics, such as drop size, drop velocity, number density and mass flux, are becoming increasingly important in testifying the numerical simulation of spray flow and combustor design. In spite of their importance, it has been difficult to measure these characteristics locally and simultaneously by the conventional method. On the other hand, recently, laser diagnostic techniques have developed rapidly. In particular, the PDA (Phase Doppler particle analyzer) system has been popular, and the results are discussed by some researchers who compare it to the conventional method. This study aims to clarify the spray characteristics of an air blast atomizer by PDA, and offers data for combustor design and numerical simulation of spray flow. In this report, the spray characteristics of the plain-jet atomizer were measured by PDA and discussed qualitatively.

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Mie scattering technique with silicon oil droplets (MSOD) has been applied in a laminar premixed flame in a stagnation point flow. A 1.2W laser beam of 514.5nm wavelength has been used as a light source, and fine silicon oil droplets (diameter<2μm, boiling point≒300°C) are added in the combustible mixture of propane with air. High-intensity Mie scattering from silicon oil droplets is observed in the upstream region of the flame zone. In the downstream region of the flame zone, very low-intensity Mie scattering is observed, though droplets are vaporized at the flame zone. It is confirmed that the low-intensity Mie scattering comes from solid particles (silicon dioxide, …) made from vapor of the silicon oil droplets at the flame zone. The results also show that no difference of the flame location and the extinction has been observed in cases with and without silicon oil droplets.

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Based on the existentialistic concept for the existence of a human being, the relationship between the freedom inherent in a human being and engineering is studied in this paper, taking into account two representative examples of engineering subjects; i.e., design and environmental systems. As a result, the ability to create originality avoiding conventionality, the essential motive of leading us to new ideas, and the inevitable limit of the engineering analysis of human activity have been clarified as to how and where they are brought about or exist in connection with the existence of a human being.

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Experimental basic research is performed for the indentification of cavitation bubbles or other bodies in liquid flow through ducts, valves, or impellers by using a pressure wave as a detector. In rectangular closed tanks of 200×337×250mm (made of acrylic resin) and 300×450×400mm (made of brass) filled with water, a pulse-shaped pressure wave is generated by an instantaneous small spark discharge. The pressure fluctuation due to the pressure wave is measured at a point on the wall by a high-frequency pressure transducer, and the data are recorded by A/D converter. The measured wave fluctuations differ from one another, depending on wall condition and the existence of and size of bodies in water. When we use acrylic resin and brass as wall material, both the phase and amplitude of the reflecting wave are changed due to the wall condition. When stainless steel spheres with diameters of 50.8, 30.2, and 19.1mm are set within the tank, the pressure wave passes through the sphere and diffracts around it. By interpreting the precisely measured output pressure wave signals, we can identify bodies of simple shape.

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Although it is generally known that the Karman vortex street consists of large-scale vortex structures with three-dimensional characteristics, the causes of three-dimensional instability have not yet been elucidated. In this study, the flow of the separated region over a circular cylinder was observed by using the laser light sheet technique in the Reynolds number range of 230 to 1340 in a towing water tank. As a result, it was determined that the three-dimensional features of laminar boundary layer separation over a circular cylinder were characterized by the recirculating flow in the separated region. The relationship between three-dimensional instability and Reynolds number was investigated.

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A new method is developed using a semiconductor laser and optical fiber to measure the local velocity of magnetic fluid flow. In this method, the local flow velocity is obtained by measuring the time taken for a tracer particle to pass between two sets of optical fiber probes. After this method is adjusted with a rotational flow in a rotating channel, it is applied to magnetic fluid flows in an open channel under the influence of a traveling magnetic field which is produced with a stator of a single-sided linear induction motor. As a result, it is clarified that the flows are mainly induced opposite to the traveling direction of the magnetic field and the magnitude of induced velocity is almost proportional to the frequency of the magnetic field, increasing especially near the free surface. The velocity distributions are quite different from of non magnetic fluid flow in an open channel.

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The transport equation has become an extremely important topic in physics and engineering. In this paper, to describe the motions of polar fluids microscopically, the mixed problems for the transport equations of polar fluids are considered from a mathematical point of view. The transport equations of a polar fluid consisting of two particle components, a solvent and a polar particle, are obtained by the extended Carlemann's method. To consider the infinitesimal particle surface deformation, the component particles are hypothetically divided into the following parts: (i) an open sphere with rigid body, and (ii) a boundary part with elastic body. This modelling is more important from the standpoint of systematizing the statistical theory for cluster phenomena of magnetic fluids and molecular aerothermodynamics.

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An experimental study has been performed to determine melting heat-transfer characteristics along a horizontal heated circular cylinder immersed in a solid-gas-liquid three-phase fluidized bed. A mixture of ice particles and ethylene-glycol aqueous solution was utilized for testing liquid ice. Measurements were carried out under a variety of parameters such as air-flow rate, heated-tube diameter, and initial concentration of aqueous binary solution. It was found that the heat-transfer coefficient for the fluidized liquid-ice bed might be more than twenty times as large as that for a fixed liquid-ice bed.

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Considering the increasing necessity to develop a method of microscale measurement of thermal diffusivity, the laser-beam focusing method was studied. The principle is based on the forced Rayleigh scattering method which is capable of absolute high-speed and remote-sensing measurement of fluids and solids. Local values of 100μm in diameter on polymer samples were successfully measured with an estimated error of ±10%. Local anisotropy of the thermal diffusivity due to molecular orientation of poly-methyl-methacrylate was also studied. This is expected to result in a new means of studying the microstructure of materials and local heat transfer of microscale devices.

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Infrared and far infrared rays which have major effects on radiation heat transfer are electro-magnetic waves generated by thermal motions of molecules. This fact makes it possible to estimate the characteristics of emission and/or absorption of thermal radiation by materials by applying simulations of molecular motions. In this study, pure rotational (far infrared) spectra of systems of diatomic molecules are calculated by means of the molecular dynamics method. Rigid body molecules and periodic boundaries are used. Intermolecular interactions are considered assuming a potential function which involves Lennard-Jones and Coulomb terms. Calculations were performed under several densities which correspond to conditions ranging from gas to liquid phases. A typical peak seen in gas phases disappears in liquid phases. Spectra of some systems under intermediate densities are also calculated.

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A new-type rotary stirling engine which consists of two rotary engines, one which is used for high-temperature processes and another for low-temperature ones, is proposed. The engine mounts tubular heat exchangers, not regenerative ones such as in an ordinary reciprocating stirling engine. This system can realize a simpler heat exchanging process which could not be attained in the ordinary system, and can turn the engine at a higher speed. Cycle calculation shows that this system has a thermal efficiency close to that of a Carnot cycle

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