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Building Simulation 2023年第3期16卷 427-441页

作者： Cong Li Sung-Jun Yoo kazuhide ito College of Ocean and Civil Engineering Dalian Ocean UniversityDalian 116023China Faculty of Engineering Sciences Kyushu UniversityFukuoka816-8580Japan

A significant feature of the indoor environment is the heterogeneity of airflow and pollutant distributions,which are primarily dependent on ventilation *** the case of short-and high-concentration exposures to hazardous chemical pollutants,it may be necessary to precisely determine the concentration in the breathing zone or,more directly,the inhalation exposure concentration in the respiratory tract,rather than the representative room average concentration in an indoor environment,because of the non-uniformity of pollutant concentration *** this study,we developed a computer-simulated person with a detailed respiratory system to predict inhalation exposure concentration and inhalation dose via transient breathing and reported a demonstrative numerical simulation for analyzing acetone concentration distributions in a simplified model *** numerical analysis revealed that the ventilation efficiency distribution in a room could change significantly by changing the design of the ventilation system,and that the inhalation exposure concentration estimated by a computer-simulated person could differ from the representative concentration,such as perfect-mixing or volume-averaged acetone concentration,by a factor of two or more.

关键词： computational fluid dynamics computer simulated person inhalation exposure numerical respiratory tract physiologically based pharmacokinetics tissue dose

Investigation of transient and heterogeneous micro-climate around a human body in an enclosed personalized work environment

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Energy and Built Environment 2020年第4期1卷 423-431页

作者： Chong Wang Sung-Jun Yoo Shin-ichi Tanabe kazuhide ito Interdisciplinary Graduate School of Engineering Sciences Kyushu UniversityJapan Faculty of Engineering Sciences Kyushu UniversityJapan Faculty of Science and Engineering Waseda UniversityJapan

Heterogeneous distribution of indoor environmental quality is known to have a great impact on human health,comfort,and productivity.A personalized work environment,that creates a localized and independent environ-ment with capsules or partitions,is being developed worldwide to provide workers with a space that enables undisturbed concentration on studying and ***,the minimized interior space of a personalized work environment can immediately cause adverse health impacts for occupant if the air quality and thermal en-vironment in the personalized work environment is not controlled ***,constant breathing can sharply increase the CO 2 concentrations in an interior space with an insufficient ventilation *** order to design a healthy and comfortable indoor environment,especially in a personalized work environment,it is important to predict precisely and comprehensively the transient and heterogeneous structure of the indoor envi-ronment formed around a human *** this background,we have developed an in silico human model that integrates a computational human model(virtual manikin combined with thermoregulation models)and respi-ratory model(virtual airway)for estimating indoor environmental quality,targeting the microclimate around a human body and breathing zone with high *** this study,we report the applicability of a comprehensive in silico human model to estimate the environ-mental quality in a personalized work environment.A coupled analysis of heat and contaminant transfer with computational fluid dynamics was conducted targeting the space around the in silico human model installed in a virtual personalized work *** informative data including human thermal comfort and breathing air quality were obtained,potentially forming the basis for the development of a digital twin of the personalized work environment and contributing to the design of a healthy,comfortable,and productive personalized work environme

关键词： Microclimate Indoor environment Digital twin Personalized work environment Computational fluid dynamics in silico human model

Experimental study of oil mist characteristics generated from minimum quantity lubrication and flood cooling

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Energy and Built Environment 2021年第1期2卷 45-55页

作者： Yiwen Wang Alicia Murga Zhengwei Long Sung-Jun Yoo kazuhide ito Tianjin Key Lab.of Indoor Air Environmental Quality Control School of Environmental Science and EngineeringTianjin UniversityTianjin 300072China Faculty of Engineering Sciences Kyushu UniversityJapan

The use of metalworking fluids during machining can generate oil mist and endanger the health of *** order to study the characteristics and emission laws of oil mist generated by machining,this study constructed a test bench to simulate the turning *** affecting the oil mist generated in the minimum quantity lubrication(MQL)mode and flood cooling mode were studied by means of single-factor experiments,and the formation mechanisms of oil mist were *** results show that the oil mist generated by the MQL system has two main sources,the initial escape of oil mist into the air and the evaporation/condensation of oil *** centrifugation has almost no effect on oil mist formation in the MQL *** mass concentration of oil mist generated by the MQL system is proportional to the cutting oil flow *** the work-piece is at room temperature,increasing the air supply pressure and nozzle distance,increases the oil mist mass *** the flood cooling mode,the concentration of centrifugal aerosol is linearly and positively correlated with the relative centrifugal force generated by the work-piece,and the coefficient of determination(R 2)is above *** oil mist mass concentrations in MQL mode is 8.33 mg/m^(3)~305.88 mg/m^(3).The MMD and SMD are 0.74μm to 4.42μm and 0.31μm to 2.14μm,*** oil mist mass concentrations in flood cooling mode is 0.2 mg/m^(3)~22.42 mg/m^(3).The MMD and SMD are 1.81μm to 6.58μm and 0.45μm to 5.13μm,respectively.

关键词： Oil mist Metalworking fluids Minimum quantity lubrication Flood cooling Turning

Decreasing inhaled contaminant dose of a factory worker through a hybrid Emergency Ventilation System:Performance evaluation in worst-case scenario

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Energy and Built Environment 2020年第3期1卷 319-326页

作者： Alicia Murga Zhengwei Long Sung-Jun Yoo Eisaku Sumiyoshi kazuhide ito Faculty of Engineering Sciences Kyushu UniversityJapan School of Environmental Science and Engineering Tianjin UniversityChina Technical Research Institute Obayashi CorporationJapan

Air pollution is detrimental to human health,causing several human *** industrial microenvironment generates high levels of indoor airborne pollutants,becoming a pervasive issue for *** is essential to im-prove the indoor air quality in this workplace by applying enhanced ventilation systems to minimize inhalation *** ventilation is used in industrial buildings because of its stratified air distribution and low ***,in case of accidental pollutant release,an enhancement is needed to minimize inhalation *** study proposes a hybrid emergency ventilation system using localized push-pull ventilation to improve the installed displacement ventilation system of a representative *** fluid dynamics was ap-plied to calculate steady-state indoor air flow and volume-averaged pollutant *** performance was evaluated in terms of source position;a computer simulated person was integrated to the building to confirm effectiveness against personal *** showed marked improvement in performance when push-pull technique was used:room-averaged concentration diminished up to 91%while ventilation rate only increased 4%.Inhaled pollutant mitigation was achieved but performance dependence against leakage source and personal position was confirmed.

关键词： Computational fluid dynamics Hybrid ventilation Industrial environment Computer simulated person Inhalation exposure

Identification of Model Parameters of Vaporized Hydrogen Peroxide Decomposi-tion Flux on Building Materials for Compu-tational Fluid Dynamics

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Journal of Environmental Protection 2016年第2期7卷 212-229页

作者： kazuhide ito Sung-Jun Yoo Hirofumi Horata Interdisciplinary Graduate School of Engineering Science Kyushu University Fukuoka Japan

To maintain healthy and sanitary indoor air quality, development of effective decontamination measures for the indoor environment is important and hydrogen peroxide is often used as decontamination agent in healthcare environment. In this study, we focused on the decomposition phenomena of vaporized hydrogen peroxide on wall surfaces in indoor environment and discussed a wall surface decomposition model for vaporized hydrogen peroxide using computational fluid dynamics to simulate the concentration distributions of vaporized hydrogen peroxide. A major drawback to using numerical simulations is the lack of sufficient data on boundary conditions for various types of building materials and hence. We also conducted the fundamental chamber experiment to identify the model parameters of wall surface decomposition model for targeting five types of building materials.

关键词： Vaporized Hydrogen Peroxide Computational Fluid Dynamics Wall Surface Decomposition Model Chamber Experiment

Design and Development of Oblique-Incident Interferometer for Form Measurement of Hand-Scraped Surfaces

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Nanomanufacturing and Metrology 2021年第2期4卷 69-76页

作者： So ito Daiki Kameoka Kimihisa Matsumoto kazuhide Kamiya Department of Intelligent Robotics Faculty of EngineeringToyama Prefectural University5180KurokawaImizuToyama939-0398Japan

Precision flat surfaces finished by hand-scraping are extensively used in the sliding parts of precision positioning systems or the surface plates of precision measuring *** hand-scraped surfaces are employed to improve the flatness of the machined surfaces and the motion accuracy of the *** numerous depressions of micrometer-scale depth on a scraped surface are thought to prevent wringing and improve the lubrication properties by forming oil *** measurement of the micrometer-scale features of a hand-scraped surface is one of the reasonable methods for investigating its effect on the motion accuracy of the positioning systems or the lubrication properties of the sliding *** a hand-scraped surface is a rough surface composed of micrometric complex features,it is difficult to conduct precision measurement of the three-dimensional surface form using conventional measurement instruments,such as vertical-incident interferometers or stylus-type *** this study,an oblique-incident interferometer based on Abramson interferometry is introduced to measure the form of a rough surface produced by *** this technique can detect high-intensity reflected light on a rough surface,it allows the measurement of the form of the hand-scraped surface in noncontact *** order to shorten the measurement time,the form calculation based on a five-step phase shifting method was introduced.

关键词： Oblique-incident interferometer Abramson interferometry Hand-scraped surface Rough surface Surface form measurement