著者

Atsushi Inagaki Yovita Wangsaputra Manabu Kanda Meral Yücel Naoyuki Onodera Takayuki Aoki

出版者

Meteorological Society of Japan

雑誌

SOLA (ISSN:13496476)

巻号頁・発行日

vol.16, pp.120-124, 2020 (Released:2020-07-23)

参考文献数

18

被引用文献数

2

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The similarity of the turbulence intensity profile with the inner-layer (i.e. from the ground to the top of the logarithmic layer) and the outer-layer (i.e. from the top of the inner layer to top of the boundary layer) scalings were examined for an urban boundary layer using numerical simulations. The simulations consider a developing neutral boundary layer over realistic building geometry with and without a slightly upsloping terrain. The computational domain covers an 19.2 km by 4.8 km and extends up to a height of 1 km, and is resolved by 2-m grids. Several turbulence intensity profiles are defined locally in the computational domain. The inner- and outer-layer scalings work well reducing the scatter of the turbulence intensity within the inner- and outer-layers, respectively, regardless of the surface geometry. Although the main scatters among the scaled profiles are attributed to the mismatch of the parts of the layer (i.e. inner or outer) and the scaling parameters, their behaviours can also be explained by introducing a non-dimensional parameter which consists of the ratio of the inner- and outer-layer parameters for length (the boundary-layer height over the roughness length), or velocity (the external free stream velocity over the friction velocity).

著者

Kyosuke Kawano Ryoko Oda Atsushi Inagaki Makoto Nakayoshi

出版者

Meteorological Society of Japan

雑誌

SOLA (ISSN:13496476)

巻号頁・発行日

vol.16, pp.192-197, 2020 (Released:2020-10-29)

参考文献数

23

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The thermal stress along a marathon course in Tokyo is evaluated using a radiation balance model. The wet-bulb globe temperatures (WBGTs) for runners and spectators are calculated based on the surrounding building and tree geometries using the Solar LongWave Environmental Irradiance Geometry model. Analysis is conducted in terms of summer days in August 2018, which was during the hottest summer in the past 5 years. The WBGT classification for runners along the outward leg (until around 14 km) reaches the “Warning” level (WBGT = 26.5°C) despite of the many shadows on the street in the early morning (until 0645 JST). The WBGT increases around the Imperial Palace because the road has a sky view factor of over 95%, and no obstacles to make shadows on the street at around 0750 JST. The WBGT classification for runners reaches the level of “Severe warning”. For spectators, the difference of average WBGT from the runners are about 0.1°C although the difference could be significant locally due to partial shading on a road side.

著者

Kyosuke Kawano Ryoko Oda Atsushi Inagaki Makoto Nakayoshi

出版者

Meteorological Society of Japan

雑誌

SOLA (ISSN:13496476)

巻号頁・発行日

pp.2020-033, (Released:2020-09-10)

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The thermal stress along a marathon course in Tokyo is evaluated using a radiation balance model. The wet-bulb globe temperatures (WBGTs) for runners and spectators are calculated based on the surrounding building and tree geometries using the Solar LongWave Environmental Irradiance Geometry model. Analysis is conducted in terms of summer days in August 2018, which was during the hottest summer in the past 5 years. The WBGT classification for runners along the outward leg (until around 14 km) reaches the “Warning” level (WBGT = 26.5°C) despite of the many shadows on the street in the early morning (until 0645 JST). The WBGT increases around the Imperial Palace because the road has a sky view factor of over 95%, and no obstacles to make shadows on the street at around 0750 JST. The WBGT classification for runners reaches the level of “Severe warning.” For spectators, the difference of average WBGT from the runners are about 0.1°C although the difference could be significant locally due to partial shading on a road side.

著者

Atsushi Inagaki Yovita Wangsaputra Manabu Kanda Meral Yücel Naoyuki Onodera Takayuki Aoki

出版者

Meteorological Society of Japan

雑誌

SOLA (ISSN:13496476)

巻号頁・発行日

pp.2020-021, (Released:2020-06-08)

被引用文献数

2

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The similarity of the turbulence intensity profile with the inner-layer (i.e. from the ground to the top of the logarithmic layer) and the outer-layer (i.e. from the top of the inner layer to top of the boundary layer) scalings were examined for an urban boundary layer using numerical simulations. The simulations consider a developing neutral boundary layer over realistic building geometry with and without a slightly upsloping terrain. The computational domain covers an 19.2 km by 4.8 km and extends up to a height of 1 km, and is resolved by 2-m grids. Several turbulence intensity profiles are defined locally in the computational domain. The inner- and outer-layer scalings work well reducing the scatter of the turbulence intensity within the inner- and outer-layers, respectively, regardless of the surface geometry. Although the main scatters among the scaled profiles are attributed to the mismatch of the parts of the layer (i.e. inner or outer) and the scaling parameters, their behaviours can also be explained by introducing a non-dimensional parameter which consists of the ratio of the inner- and outer-layer parameters for length (the boundary-layer height over the roughness length), or velocity (the external free stream velocity over the friction velocity).