Journal of Environmental Engineering (Transactions of AIJ)
Online ISSN : 1881-817X
Print ISSN : 1348-0685
ISSN-L : 1348-0685
Volume 81, Issue 721
Displaying 1-8 of 8 articles from this issue
  • Yoshifumi OHMIYA, Takayuki HIRAYAMA, Jun-ichi YAMAGUCHI, YI-Chul SHIN
    2016Volume 81Issue 721 Pages 263-271
    Published: 2016
    Released on J-STAGE: March 30, 2016
    JOURNAL FREE ACCESS
     When a fire occurs, the opening jet plumes ejected from an opening cause fire damage to adjacent space in a building. Especially it is considerable to be vital to control smoke from fire room facing vertical space such as atrium to prevent from damaging upper spaces. Then the purpose of this study is grasping the influence of horizontal soffit against opening jet plumes. In this study, a series of experiments were carried out by changing the opening shape, the depth of horizontal soffit, the length of smoke curtain, the diameter of source of fire etc. As the results, the knowledge about opening jet plumes in adjacent space with presence of a horizontal soffit could be obtained. It is possible to model the flow rate of the opening jet plumes by coefficient of involved air as parameter of opening shape and the depth of a horizontal soffit etc.
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  • Proposal of measurement method for vapor and liquid phase of water capture efficiency and difference of measuring results between this method and tracer gas method
    Kazuya ITO, Hiromi KOMINE
    2016Volume 81Issue 721 Pages 273-281
    Published: 2016
    Released on J-STAGE: March 30, 2016
    JOURNAL FREE ACCESS
     One of the performance measures of kitchen ventilation food in electrical commercial kitchens is the cooking products exhaust efficiency. The testing method for vapor and liquid phase of water exhaust efficiency is proposed for the performance test and evaluation method of electrical commercial kitchen ventilation hood because these substances are typical cooking products.
     This proposed testing method for vapor and liquid phase of water exhaust efficiency is most suitable for the performance test and evaluation method of electrical commercial kitchen ventilation hood. This method will be adopted for the cooking products exhaust efficiency of a rice cooker or a steam heated oven which emit steam intermittently because the steam in itself is the cooking products and this method identifies the exhaust efficiency of vapor and liquid phase of water. On the other hand, the tracer gas exhaust efficiency is equivalent to the cooking products exhaust efficiency beyond 90% of exhaust efficiency.
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  • Mapping the sea breeze effects for mitigating urban warming
    Kaoru MATSUO, Takahiro TANAKA
    2016Volume 81Issue 721 Pages 283-293
    Published: 2016
    Released on J-STAGE: March 30, 2016
    JOURNAL FREE ACCESS
     In coastal city, it is thought that the sea breeze has great influence on summer diurnal temperature distribution patterns. Understanding the spatial distribution of sea breeze effects will be helpful for making Urban Environment Climate Maps. Consequently, this study aims at making the maps of sea breeze effect distribution using the observed data and the numerical simulation results in Hiroshima plain. The results are revealed as follows: 1) The effect of sea breeze for mitigating urban warming is relatively larger in coastal area and the effect is smaller in the inland area. 2) The spatial distribution patterns of sea breeze effect for mitigating urban warming being made from the numerical calculation is similar to the one which is made from the observed temperature. 3) The temperatures in the area which are affected by sea breeze are also influenced by surrounding ventilation condition (SVC). On the other, the temperatures in the area which is not affected by sea breeze are not influenced by SVC.
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  • A case study on Shimokawa town, Hokkaido
    Keita YAMAZAKI, Masaya SAITO, Masanori SHUKUYA
    2016Volume 81Issue 721 Pages 295-305
    Published: 2016
    Released on J-STAGE: March 30, 2016
    JOURNAL FREE ACCESS
     This paper describes a method for analyzing the whole of community heating system from regional forest to nearby buildings, where heating demand emerges, with the concept of exergy. Firstly, we confirmed the validity of total heat loss calculated for the residential buildings by comparing it with the measured volume of biomass consumed. Secondly, based on the above mentioned “exergy” budget data, we calculated the annual exergy consumption pattern, from the forest, via to boiler, pipeline, room-space heater and to the final exergy demand. Thirdly, we also made of comparison of the annual exergy consumption pattern of the whole community heating system with well insulated buildings, to that with poorly insulated buildings which is assumed to use petrol for space with individual heating equipments. Lastly, the potential of decreasing exergy supply was discussed by comparing the difference in exergy consumption patterns due to a change in supply temperature
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  • Study about utilizing reverse simulation for CFD using the adjoint variable method
    Akane MASHIMO, Ryohei KONO, Jun NAKAGAWA, Kazunari MOMOSE, Kaoru IKEJI ...
    2016Volume 81Issue 721 Pages 307-317
    Published: 2016
    Released on J-STAGE: March 30, 2016
    JOURNAL FREE ACCESS
     The adjoint variable method (AVM) is a method for solving inverse problems, and is used for sensitivity analysis. In this study, the effective usage of inverse analysis based on AVM is considered for the purpose of its use as an approach to design.
     This paper proposes a method of inverse analysis to determine the optimal arrangement of partition walls in a station building to prevent inflow of wind in winter and to promote heat removal in summer. The analysis was applied to the design of Nobeoka station building, part of a redevelopment project being handled by Office of Kumiko Inui.
     Usage of inverse analysis based on AVM is proposed as a design approach for determining the optimal placement of partition walls in a semi-outdoor space. In the analysis, surface panels with an aperture ratio property are installed at candidate positions for the partition walls. Forward analysis (CFD) and inverse analysis (AVM) are alternated to compute the optimal aperture ratio. From the resulting aperture ratio, it was determined whether a partition walls was necessary at the candidate position.
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  • Asako HASEGAWA, U YANAGI, Naoki KAGI, Ken-ichi HASEGAWA, Naohide SHINO ...
    2016Volume 81Issue 721 Pages 319-326
    Published: 2016
    Released on J-STAGE: March 30, 2016
    JOURNAL FREE ACCESS
     Indoor air quality and climate of three temporary emergency housing units in Aso City, Kumamoto Prefecture, have been measured from August 2013 to April 2014 continuously and those results are reported in this paper comparing with those factors in Tohoku region. Outdoor air was introduced during the daytime through the year and carbon dioxide (CO2) concentrations in the three units were lower than 1000 ppm. However, CO2 concentrations were very high during the evening especially with heating and cooling equipments. A mechanical ventilation system for 24-hour ventilation was installed in the toilet and was typically run, however, the air volume can be insufficient or the route of ventilation can be inappropriate. Concentrations of chemical substances in the three units were significantly lower than guideline values and those in Tohoku area. On the other hand, fungal contamination was detected in a number of rooms that had less airflow. Good indoor air quality by the sufficient ventilation and frequent cleaning are required to support victims'health.
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  • Influence of buildings around a site on direct solar gain
    Hisato OSAWA, Taro MORI, Hiroaki HAMADA, Kosuke OGATA, Hirofumi HAYAMA ...
    2016Volume 81Issue 721 Pages 327-336
    Published: 2016
    Released on J-STAGE: March 30, 2016
    JOURNAL FREE ACCESS
     Direct solar heat gain (hereafter DSHG) is expected to decrease heating energy consumption of housings with airtightness and thick insulation in northern region. It is important to calculate precise solar heat gain through window, since the values influence on the strategy whether we should use DSHG or not. In this report, we suggest the method to calculate solar radiation in a site where build a building. Then the relationship between thermal environment and heating energy is analyzed by using the climate data combined with GIS data. The results identify that southern sky factor is able to explain an effect of DSHG.
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  • A case study of Chosegun Ichinomiyamachi, Chiba
    Sachio TOGAWA, Morikazu YAMAMOTO
    2016Volume 81Issue 721 Pages 337-344
    Published: 2016
    Released on J-STAGE: March 30, 2016
    JOURNAL FREE ACCESS
     Central Disaster Prevention Council mentions that the car evacuation is prohibited. However, as a result of the survey of the Great East Japan Earthquake Disaster, the car evacuation at the time of the disaster was accepted. Therefore, it is important that how the evacuation method at occurrence of disaster can be made to improve through the evacuation simulation is discussed.
     In this paper, we analyze evacuation distance to Tsunami Refuge Center and evacuation time using the car. First of all, the shortest evacuation route is calculated using Dijkstra's algorithm. And, in order to measure the impact of the number of vehicle car, we execute car evacuation simulation system.
     According to the results of the analysis above, it is critical that evacuation routes and evacuation time consider road width, road conditions effects such as.
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