Shinkansen railwaystations in a snowy district usually have adopted a structure (we call it "a whole covering shed") enclosing the entire track floor with a roof and side walls to keep a good environment of the station. The shed is about 400m in length, and therefore for a train passing through the station this shed is regarded as a short tunnel with large cross section. Openings are provided on the periphery of the shed to decrease the pressure variation generated by the train. The relation between the pressure inside the shed and the velocity of a flow dishcarged from an opening becomes important in the investigation of the problems concerning this pressure variation. The flow velocity is usually calculated from Bernoulli's equation for steady flow, however, the validity of the quasi-steady assumption has not been discussed in detail. In this paper, (1) the relation between the pressure variation in a station shed and the flow velocity discharged from an opening of the shed wall is formulated by using Bernoulli's equation for unsteady flow, and the validity of this formulation is examined by comparing theoretical results with experimental ones; (2) the condition under which Bernoulli's equation for steady flow can be applied in the case of the pressure variation in the station shed is examined.

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LES (large eddy simulation) of flows around a forced-oscillating circular cylinder is conducted using an ALE (arbitrary Lagrangian-Eulerian) method. For stable calculations without numerical viscosity, a discretization method which improves the conservation properties of the mass, momentum and kinetic energy in ALE coordinates, is employed. The Reynolds number based on the cylinder diameter is set to 8000. The cylinder is oscillated sinusoidally in the transverse direction with non-dimensional amplitude of 0.2 and frequencies ranging from 0 to 0.27. The results are compared with the measurements that are also carried out by authors, in terms of lock-in phenomenon. It is shown that the numerically predicted time-averaged pressure distributions and phase-averaged velocity distributions are in good agreement with the experimental data, both in the lower and the upper lock-in region. In addition, the phase difference between the cylinder displacement and the vortex shedding is consistent with previous findings. It is also clarified that the frequency range of the lock-in in LES with the present discretization method is almost the same as that of the experiment in width, while it becomes wider in the comparative calculation, where the QUICK scheme is employed for the convection terms. Such discrepancies between two calculations are prominent, especially in the stationary state and the lower frequency region.

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An air jet, which remains laminar and axisymmetric in the single-phase flow condition, is simulated numerically in the particle-laden condition. The vortex method for particle-laden gas jet proposed by the authors is employed for the simulation. An air issues with velocity U_o from a round nozzle into the air co-flowing with velocity U_a. The Reynolds number based on U_o and the nozzle diameter is 1333, the velocity ratio U_a/U_o is 0.4. Spherical glass particles with diameter 65μm are loaded at the mass loading ratio 0.025. The particle velocity at the nozzle exit is 0.68U_o. The particles impose disturbances on the air and induce the three-dimensional flow, resulting in the transition from the axisymmetric flow to the non-axisymmetric one. As the particles make the air velocity fluctuation increase, the air momentum diffuses more in the radial direction, and accordingly the spread of the jet becomes larger. The abovementioned results agree well with the trend of the existing experiments. The proposed vortex method can successfully capture the flow transition caused by the particles laden on an axisymmetric air jet.

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Some arterial diseases, such as a peripheral arterial disease can be detected by blood pressures and pulse waves using non-invasive blood pressure monitoring devices. On the other hand, some diseases, like an abdominal aortic aneurysm, are hard to find in the same way though they also make influence to pulse waves. The aim of our research is to propose new method to detect such diseases. This paper shows two identification methods of pulse wave propagation characteristics in arteries under the assumption that arteries are viscoelastic tube. One method identifies material parameters, stiffness and density of a viscoelastic tube by measuring pressures at three points and flow volume at one point. The other method identifies them by measuring pressures at four points. Two proposed methods were verified by experiment using a silicon tube.

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It is very important to remove contaminant fully from waste PET bottles for bottle-to-bottle recycling. We succeeded in solving the first step of mechanism to remove contaminant from waste PET bottles as has been mentioned in the former paper. In this paper the final step of mechanism is proposed. It is made up of the aggregation of contaminant based on the Brownian coagulation. We solved the kinetic equation of coagulation in the contaminant concentration less than 0.4% on a beaker scale. Then we confirmed the same equation on a industrial scale. We conclude that the contaminant on waste PET bottles is fully separated from PET bottles under the proper separating condition, such as the quantity of extract, separating temperature and time, not depending on the quantitative scale of separation, such as beaker scale or industrial scale.

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A self-vibration heat pipe having a meandering capillary tube can operate on top and horizontal heat mode without gravity effects. However, the behaviors of the working fluid in the pipe have not been well studied. In this study, the working fluid in the self-vibration heat pipe was visualized by neutron radiography system in Japan Atomic Energy Agency. The liquid columns formed in the cooling area were visualized at 200 frames/s in the meandering channel. Image processing methods to show the vibration of the liquid column were developed. It was shown that the liquid columns were vibrated around the cooling area and supplied to the heating area. The heat was transported from the heating area to the cooling area. The maximum effective thermal conductivity of the plates were about 20 times of aluminum. The flow pattern was evaluated at the volumetric ratio of liquid phase in the heat pipe. The periods of the vibration were predicted fairly well by a mass-spring model.

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A fuel cell system which uses hydrogen from fuel reforming, needs combustion heat of the residual gas from the fuel cell to support the endothermic reforming reaction and the evaporation of fuel. In the case of methanol reforming fuel cell, the residual gas contains hydrogen together with large concentration of carbon dioxide, which is more than 60 vol.%. New type combustor is needed for the combustion of the residual gas in wide mixture range, under low CO emission and low temperature for low damage of reforming catalysts. Thin plate type catalytic combustor using millimeter-scale protuberances is proposed and the combustion characteristics are examined comparing with conventional combustor. Proposed plate type catalytic combustor provided wide combustible range with residual gas of the reforming fuel cell, low CO emission lower than 50ppm low temperature combustion and low-pressure loss with combustor thickness smaller than 5.5mm The combustible range and combustion efficiency is effectively controlled by the height of protuberances and layout of fuel injection holes.

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In this study, Fatty acid methyl ester (FAME) becomes light quality by mixed with light cycle oil (LCO). This method has the effect that physical characteristic of FAME is improved. This paper describes the ignition, combustion and soot formation characteristics in the mixed fuel of FAME and LCO. The soot formation characteristics of the mixing fuels is investigated by Laser Induced Incandescence (LII) in the constant volume combustion vessel. The result of this experiment shows the ignition characteristics of the fuel and amount of soot formation is controlled by changing the mixed ratio of FAME and LCO. In other word, the ignition delay is shortened and the soot formation characteristic decreases as mixing ration of FAME increase.

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In order to use palm oil methyl ester (PME) as a base fuel of the biodiesel, PME with 1-butanol (BPME) is tested using a DI diesel engine. The 1-butanol content in BPME is 10 to 30mass%. There is no problem in the startability and stability of the engine operation with BPME. Thermal efficiency of BPME is almost the same as that of PME and JIS no.2 gas oil. Although BPME has longer ignition delay compared with PME due to the low cetane number of 1-butanol, the combustion end timing of BPME is same. The smoke emissions of BPME decrease with increasing 1-butanol content although the HC and CO emissions increase due to the longer ignition delay. When the 1-butanol content in BPME is 15mass%, BPME has almost the same ignition delay and HC and CO emissions compared with the gas oil. From the experimental results, it is concluded that PME is better than RME as a base fuel of the biodiesel with 1-butanol due to the better ignitability and lower exhaust emissions of BPME.

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The unburned hydrocarbon (UHC) and carbon monoxide (CO) emissions from ultra-high EGR low temperature diesel combustion can be attributed to lowered combustion temperature due to EGR and existence of under-mixed fuel-rich mixture around spray tip, over-mixed fuel-lean mixture near injector, and fuel missing the piston bowl. Two-stage injections have the potentials to reduce UHC and CO emissions with decreasing these mixtures. In this study, the effects of two-stage fuel injection including the dwell between the two injections and fuel quantity in each injection on the UHC and CO emissions were investigated. With optimized dwell and injection ratio, the two-stage injection can reduce UHC and CO emissions but these emissions are still at high levels in the regime of low-oxygen low-temperature combustion.

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