Journal of Environmental Engineering (Transactions of AIJ)
Online ISSN : 1881-817X
Print ISSN : 1348-0685
ISSN-L : 1348-0685
Volume 79, Issue 705
Displaying 1-7 of 7 articles from this issue
  • Predictability of major combustibility indices from material properties
    Osamu ITOGE, Koji KOURA, Toshihiko NAGAI, Yuji HASEMI, Osamu KATSURA, ...
    2014Volume 79Issue 705 Pages 909-918
    Published: November 30, 2014
    Released on J-STAGE: November 30, 2014
    JOURNAL FREE ACCESS
    In this study, for the purpose of understanding combustibility of cellular plastic insulation to estimate fire protective performance, three kinds of combustion tests are conducted, cone calorimeter method, oxygen index and TG-DTA analysis. Standing on the results of their combustion tests, the combustion property of each types of cellular plastic insulation is described with focusing on three aspects, ignitability, primary peak heat release rate and total heat release per unit mass. Then, about each types of cellular plastic insulation, it is clarified material property which has high correlation with each aspects, ignitability, primary peak heat release rate and total heat release per unit mass.
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  • Masatoshi NAKAMURA, Shintaro MICHIKOSHI, Daisuke KAMIKAWA, Yuji HASEMI
    2014Volume 79Issue 705 Pages 919-925
    Published: November 30, 2014
    Released on J-STAGE: November 30, 2014
    JOURNAL FREE ACCESS
    The objective of this study is to discuss whether the flame buoyancy increases vent flows in fully-developed compartment fires. Vent flows of small-scale compartments with narrow frontages were measured. Different ceiling heights of the compartments were set to vary the work of flame buoyancy. Greater vent flows were observed under the conditions with high ceiling. Calculated vent flows were more consistent with experimental data when the effect of flame buoyancy was taken account in, compared with when it was not considered. It was concluded that the flame buoyancy had the effect on vent flows of these compartments.
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  • Ryuta TOMITA, Katsuo INOUE
    2014Volume 79Issue 705 Pages 927-935
    Published: November 30, 2014
    Released on J-STAGE: November 30, 2014
    JOURNAL FREE ACCESS
    In this research, we examined effect of vibration sense by frequency characteristics of impact vibration for residential floor. As the result, we got the followings: (1) We showed that the frequency of 30Hz or more also affect the vibration sense of human, (2) We showed that the broadband waveform, as compared to the narrow band waveform, the influence of the vibration sense of human is large, (3) We showed that when it comes to broadband, as compared to the narrow band, to perceive even a small vibration of about 4-5dB.
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  • Goro YOSHIDA, Yoshiaki UETANI
    2014Volume 79Issue 705 Pages 937-945
    Published: November 30, 2014
    Released on J-STAGE: November 30, 2014
    JOURNAL FREE ACCESS
    Venetian blinds are usual devices for controlling daylight admittance. The spectral transmittance of venetian blinds is affected by shapes, reflective properties of the slats, and the direction of incident light. We incorporate these factors into a method for calculating the spectral transmittance directivity of the blind. The slats are assumed to be arcs on a two-dimensional cross section, which constitutes a Lambertian surface of negligible thickness. The spectral irradiance distributions on the slats and virtual elements in optical directions are calculated by two-dimensional spectral interreflection. The spectral irradiance distributions are then transformed into a three-dimensional spectral BTDFλ. The BTDFλ and transmittance are determined from the incident direction of the direct radiation and the blind geometry. Using the proposed method, we can calculate the spectral irradiance distributions of rooms shaded by venetian blinds. The result shows quantitatively that the spectral reflective properties and angles of the slats affect the spectral transmittance directivity of the blinds and spectral irradiance distributions of the room.
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  • Hiroki KAWASHIMA, Makoto SATOH, Kozo TAKASE, Aya NAKAGAWA, Maya ISHIWA ...
    2014Volume 79Issue 705 Pages 947-956
    Published: November 30, 2014
    Released on J-STAGE: November 30, 2014
    JOURNAL FREE ACCESS
    On the Pacific side of Japan, we can take advantage of rich solar energy in winter times to design the low cost passive solar heating system by the direct solar gain through glazing. To keep the room air temperature warm and comfortable only by the passive way, it is important to design the balance among heat gain, heat loss, thermal mass, and thermal mass area. First, we focused on PCM (Phase Change Material), light enough for Japanese wood structure houses to have greater heat capacity, and proved its performance by the actual space experiment. Based on this result, we made the numerical model to simulate the room air temperature with PCM. Finally, we proposed an easy evaluation method to find the better combination of the four, using Southern window area to Q-value charts with adaptable time rate estimation.
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  • Shintaro IKEDA, Ryozo OOKA
    2014Volume 79Issue 705 Pages 957-966
    Published: November 30, 2014
    Released on J-STAGE: November 30, 2014
    JOURNAL FREE ACCESS
    Recently, a residual battery and a thermal storage tank (TST) have become increasingly important for controlling a power system frequency because they enhance the amount of energy generated from renewable resources. Although there are many studies about system optimization without storage systems, they are included in few optimization studies. Some mathematical programming methods have been used to optimize an operation schedule for these systems. Although they can theoretically derive results, their execution time is overly long. Therefore, the authors have used metaheuristics to develop an optimization method for operating a residual battery, a TST, and output of heat sources. This method is faster than mathematical programming methods for deriving a semi-optimal solution for an energy system including a residual battery and a TST.
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  • Study on evaluation of inhomogeneous outdoor thermal environment using CFD analysis method coupled with a multi-node human thermoregulation model (Part 1)
    Shinji YOSHIDA, Taiki SATO, Masayuki OGURO
    2014Volume 79Issue 705 Pages 967-977
    Published: November 30, 2014
    Released on J-STAGE: November 30, 2014
    JOURNAL FREE ACCESS
    In this paper, we propose a new calculation method for evaluating the inhomogeneous outdoor thermal environment by incorporating a multi-node human thermoregulation model into the simulation method based on CFD analysis of the outdoor thermal environment. We also investigated the effects of weather conditions on the inhomogeneity of the radiant environment for pedestrians using the proposed calculation method. Two different weather condition cases are investigated in this study: (1) a scorching hot day and (2) a cloudy day. The analysis confirmed the effectiveness of the proposed method in the evaluation of the inhomogeneity of the radiant environment in outdoor space.
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