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Onodera, Naoyuki; Idomura, Yasuhiro; Hasegawa, Yuta; Nakayama, Hiromasa
Dai-36-Kai Suchi Ryutai Rikigaku Shimpojiumu Koen Rombunshu (Internet), 3 Pages, 2022/12
We have developed a wind simulation code named CityLBM to realize wind digital twins. Mesoscale wind conditions are given as boundary conditions in CityLBM by using a nudging data assimilation method. It is found that conventional approaches with constant nudging coefficients fail to reproduce turbulent intensity in long time simulations, where atmospheric stability conditions change significantly. We propose a dynamic parameter optimization method for the nudging coefficient based on an ensemble Kalman filter. CityLBM was validated against plume dispersion experiments in the complex urban environment of Oklahoma City. The nudging coefficient was updated to reduce the error of the turbulent intensity between the simulation and the observation. The mean error of velocity variance is reduced by 
10% compared to the conventional nudging method with a constant nudging coefficient.
Onodera, Naoyuki; Idomura, Yasuhiro; Hasegawa, Yuta; Nakayama, Hiromasa
Dai-35-Kai Suchi Ryutai Rikigaku Shimpojiumu Koen Rombunshu (Internet), 3 Pages, 2021/12
A detailed wind simulation is very important for designing smart cities. Since a lot of tall buildings and complex structures make the air flow turbulent in urban cities, large-scale CFD simulations are needed. We develop a GPU-based CFD code based on a Lattice Boltzmann Method (LBM) with a block-based Adaptive Mesh Refinement (AMR) method. In order to reproduce real wind conditions, the wind condition and ground temperature of the mesoscale weather forecasting model are given as boundary conditions. In this research, a surface heat flux model based on the Monin-Obukhov similarity theory was introduced to improve the calculation accuracy. We conducted a detailed wind simulation in Oklahoma City. By executing this computation, wind conditions in the urban area were reproduced with good accuracy.
Saito, Kimiaki
Tokyo Denryoku Fukushima Daiichi Genshiryoku Hatsudensho Jiko Ni Yoru Kankyo Osen No Kenkyu Chosa No Shinten To Kadai (Internet), p.8 - 10, 2020/07
no abstracts in English
Komatsu, Teruhisa; Adachi, Takeo
Journal of Applied Meteorology, 42(9), p.1330 - 1334, 2003/09
no abstracts in English
Amano, Hikaru
Fusion Science and Technology, 41(3), p.488 - 492, 2002/05
no abstracts in English
Koarashi, Jun; Amano, Hikaru; Atarashi-Andoh, Mariko; Iida, Takao*; Koma, T.*
Radiation Protection Dosimetry, 93(3), p.237 - 243, 2001/00
Times Cited Count：8 Percentile：52.36(Environmental Sciences)no abstracts in English
*
JNC TJ7420 2000-007, 28 Pages, 2000/03
JNC-TJ7420-2000-007.pdf:11.92MB
no abstracts in English
Rn flux from ground surface based on the variation analysis of Rn concentration in a closed chamberKoarashi, Jun*; Amano, Hikaru; Atarashi-Andoh, Mariko; Iida, Takao*
Radiation Protection Dosimetry, 87(2), p.121 - 131, 2000/01
Times Cited Count：24 Percentile：80.82(Environmental Sciences)no abstracts in English
Yamazawa, Hiromi; Nagai, Haruyasu
JAERI-Conf 99-001, p.151 - 160, 1999/03
no abstracts in English
Yamazawa, Hiromi; Nagai, Haruyasu
JAERI-Data/Code 97-041, 56 Pages, 1997/10
JAERI-Data-Code-97-041.pdf:1.32MB
no abstracts in English
Amano, Hikaru; Matsunaga, Takeshi; Ueno, Takashi; Onuma, Yoshikazu*; Watanabe, Miki*; Yanase, Nobuyuki; Nagao, Seiya; Sukhoruchkin, A. K.*
Proceedings of 5th International Scientific and Technical Conference on the Problems of Liquidation of Chernobyl Accident Consequences, P. 74, 1996/00
no abstracts in English
; Yamazawa, Hiromi
JAERI-Research 95-016, 22 Pages, 1995/03
JAERI-Research-95-016.pdf:0.88MB
no abstracts in English
Yamazawa, Hiromi
Hoken Butsuri, 29(4), p.437 - 440, 1994/12
no abstracts in English
Mukai, Masayuki; Takebe, Shinichi; Komiya, Tomokazu
JAERI-Research 94-014, 25 Pages, 1994/09
JAERI-Research-94-014.pdf:1.23MB
no abstracts in English
