This paper describes the prediction on attenuation of a silencer tower with many resonators by using FEM. The purpose of this study is to realize the reduction of infra sound which is generated in various plants. The attenuation is firstly predicted by a conventional method and secondarily calculated by FEM. In modeling of FEM, optimal mesh number is determined so that the variation of the natural acoustic frequency becomes within 10% of the detailed model by the calculating with various mesh models, because the fine mesh model consumes much time to calculate. Finally, the experiment is performed and the calculated result is compared with the experimental one. As a result, it was clarified that the attenuation of a complex silencer with many resonators could be predicted by the finite element method. And the attenuation calculated by the conventional method could also be predicted by taking into account of 70% the value of the calculated result.

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Turbulent separated flow structure was studied by the phase averaging analysis to avoid the difficulty in the data acquisition of the phase angle of the time dependent signal with frequency modulation. This study proposed a new method of phase averaging by the wavelet transformation, and compared the results of the phase averaging by the wavelet transformation with those by the traditional phase averaging technique. These two techniques of the phase averaging, using the experimental data of the velocities in a periodically fluctuating separated flow, showed noticeable difference between their results. If the velocity signals include the frequency modulation, many shapes of velocity profiles by the traditional phase averaging technique will be nearly the same, and be similar to those of the time-averaged velocity. The wavelet transformation, however, showed the clear difference in the velocity profiles at each phase angle even for the velocity signals with modulated frequency.

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Heavy automotive tire wastes were pyrolysed in a fixed-bed fire-tube heating reactor system under N₂ atmosphere to determine the role of final temperature, feed size, sweeping gas flow rate and heating rate on the product yields and liquid product compositions. Final temperatures studied were 375, 425, 475, 525 and 575°C and the highest liquid product yield was obtained at 475°C for feed size of 4cm³, sweeping gas flow rate of 8 L/min and heating rate 15°C/min. Liquid products were characterized including fuel properties, elemental analyses, FT-IR, ¹H-NMR, GC-MS. In addition, boiling point distributions of hydrocarbons in pyrolytic liquids were determined by using simulated distillation curves in comparison with commercial diesel fuel. The analytical results of the product liquids showed that the major compounds in the liquid products were: limonene in large quantities, some long-chain hydrocarbons and small amount of single ring alkyl-aromatics. The fuel properties and simulated distillation results represent that the total pyrolytic liquid can be used as liquid fuel.

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The Stirling engine (SEG) that uses waste product and biomass as fuel is a clean energy system with few greenhouse gas discharges. However, improvement of generation efficiency and development of a product are required strongly. In this paper, the energy flow is investigated in experimenting in Test SEG. These results are installed into the energy demand pattern of cold region houses with much heat demand, and the amount of fuel consumption, power generation efficiency, and a greenhouse gas amount of emission are investigated. Operations of the proposed system are SEG base-load operation and SEG power-load-following operation. Moreover, when there is less exhaust heat of the SEG than a heat demand amount, the electric heat pump is operated. From analysis results, the energy cost, the greenhouse gas emission characteristic, the auxiliary heat source, and the operation plan of a heat storage tank due to the conventional method and the proposed system were described. It is thought that greenhouse gas and the energy cost of the SEG cogeneration made to follow power load are advantageous compared with the SEG base load operation. However, it turned out that improvement in the speed of the load response characteristic of the SEG is required as a future subject.

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A unique solar thermal electric system is proposed and tested in the present study. In this system, an organic working fluid, which is suitable for a temperature range appropriate for solar energy, is adopted. We call this system as “solar organic Rankine cycle system” (SORCS). In order to improve the thermal efficiency by using solar energy, a displacement-type scroll expander and compound parabolic concentrator (CPC) solar collector are used. This system consists of very simple components that are similar to the ones used in an air conditioner and is very cost effective. The present paper reports on the experimental results of the scroll expander unit and the practical operation of the proposed SORCS under actual solar radiation input. The total thermal efficiency of the present SORCS attains 7% (42% when cooling water is used for the cogeneration system).

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In vehicle systems or construction machinery occupational drivers might be exposed to vibration for a long time. This may cause ache of the spine such as low back pain. Therefore, it is necessary to evaluate the influence of vibration on the spinal column. For this purpose, the vibration experiment is conducted to measure in detail the response of the spinal column. Modal parameters of upper human bodies are identified by using measured transmissibilities. As the results, three modes are observed within the range 4Hz to 20Hz. The first mode is characterized by the composition in the sagittal plane of the head rotation and the spinal bending. The second mode shows the relative motion of the lower trunk (lumbar vertebrae). The significantly large motion of the sacrum might cause the increase of the spinal load, the lowest intervertebral disc showing the largest deformation. Finally, the main characteristic of the third mode is the neck deformation. In Addition, the human transmissibilities are compared using different averaging methods.

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The flow field characteristics of confined flames have been investigated for propane nonpremixed flames in cylindrical furnaces. The effects of furnace inner diameter D₁, air inlet velocity difference ΔU_a, and global equivalence ratio φ on the flow field are related to NOx emission. The emission index of NOx, EINOx, decreases roughly with the increases of the above parameters. This decrease is observed as a consequence of flame stretch and dilution by the burned gas. The flame stretch is related to the velocity difference introduced by multiple inlets, and the dilution is attributable to the recirculation structure formed at the bottom of the furnace. The present investigation shows the mechanism of burner/chamber configuration inciting the flow field and indirectly controlling NOx emission.

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The overall objectives of this study were to use waste flue gas as the activation gas to produce desulfurizers with industrial-scale size, to find the appropriate activated coke and the optimal preparation method, and to determine the operating conditions for the activated coke preparation. The effects of H₂O, CO₂ and O₂ contents in the flue gas were investigated to determine the optimal operating conditions. The results showed that the higher the content of carbon, volatile and calcium oxide (THC) in a coal was, the better the Brunsuer-Emmett-Teller (BET) surface area and the pore volume are due to the increased activating temperature and decreased particle size. The activated coke, loaded with coal tar and finally activated with the flue gas at 800°C, exhibited the best desulfurizing performance with a sulfur retention of about 101 mg-SO₂/g-activated coke at a reaction temperature of 100°C. The mechanism for SO₂ removal by activated coke shows that the BET surface area, pore volume and THC have a significant influence on SO₂ removal efficiency.

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