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Field observation of wind fields has been carried out by using a doppler lidar and meteorological radars. Characteristics of fluctuational wind under cumulus convection and the growth of boundary layer including not only the effect of ground friction caused by surface roughness but also the effect of gust caused by up/down draft was examined and clarified. Some observed cases with the down flow under cumulus during passages of cold front were examined. The wind fields were simulated by large eddy simulation with canopy model, cloud physics model and boundary condition from simulated wind field by meteorological model WRF. The simulated wind fields consist with the observation. The wind speed near the ground increases with the down flow under the cumulus convection.

Falling properties of cinder models, non-simple shaped objects, were measured and three-dimensional falling trajectories were obtained by using video movies. Aerodynamic characteristics of cinder models were examined by the trajectory. The falling models imitated the configuration of cinders collected at the site of the experiment, Sakurajima volcano. Two types, one with sharp edges and one without sharp edges, were selected as representatives and a sphere was selected as reference model. The results showed that the drag coefficient varied with the falling velocity becoming smaller as the velocity increased. When the models fell with terminal velocity, the drag coefficients of the cinder models without and with sharp edges were about 0.5 and 0.6, respectively. The drag coefficient of the sphere model was about 0.3.

Typhoon Jebi made landfall over Kinki region on September 4, 2018 bringing with it strong winds and storm surge in along Osaka Bay. This is a comprehensive study carried out on the disaster caused by the typhoon. The study examined and surveyed the characteristics of strong winds, spatial distribution of gusts, lightning strikes, rainfall and damages to various structures. It also reports the outline of the meteorological features of the typhoon.

In this paper, damage to buildings in Uki City, Kumamoto was investigated using information of building and damage included in the "Victims Master Database System", which was installed because of 2018 Kumamoto Earthquake. As a result, disaster resistant indexes of buildings like structural material and building year were extracted from a house tax roll included in the system. And outline of damage in large area was understood using information of victim's certificate and tax reduction in the system. However, it was a little difficult to combine the information of victim's certificate and house tax roll because their formats are different. The information which governments have is really helpful to investigate damage and expect risk due to disaster.

Damage to buildings or houses in strong wind like typhoon or tornado are caused by flying debris such as roof tile in most cases. Measuring aerodynamic characteristics of flying debris is required to predict the motion of flying debris and to evaluate the impact for the wind resistant design of claddings and the reduction of damage to houses. This study aims to measure the aerodynamic characteristics of flying debris. Stand-alone measuring device assembled with microcomputer, three-axes accelerometer, gyro sensor, pressure sensors, SD card and small battery was built in three types of models of flying debris. These models were dropped from the stage located at 50m in the dome with no wind, and pressures, acceleration and angular velocity were measured, while capturing the motion of models by taking movies with video cameras and conducting image analysis. Based on the result of the measuring, the motion and wind force acting on each model was calculated.

Damages to houses in strong wind, e.g. typhoon or tornado, are caused by flying debrisin most cases. The configuration of flying debris such as branches of tree, pebbles, piecesof broken structures and so on is categorized as a "bluff body". Therefore, prediction offlying motion of bluff body is important to evaluate the impact of flying debris for thewind resistant design of claddings and the reduction of damage to houses.This study aims to develop a system to measure the motion of bluff body and to clarifyaerodynamic characteristics of flying debris. Some units of micro-computer, three axisaccelerometer, pressure sensors, A/D converter, Wi-Fi adaptor and small battery wereassembled as a stand-alone probe to measure the motions and wind forces on a flyingbody. The measuring probe was built in a rectangular shaped test body. The test body wasdropped in a test region with no wind. The pressure and the acceleration on the test bodywere measured, while capturing the motion of the body by taking movies with videocameras and conducting image analysis.

Our research group is developing a platform to evaluate the strong wind risk of buildings. A data-base of configuration of building was made by field survey at some real cities. Residential or no-residential house, number of stories, configuration of roof, material of claddings and material of roof were chosen as elements of wind resistant characteristics. The method to extract the elements from the database constructed by the field survey was examined by relating to the numerical database of building configuration on GIS system. The procedure of extraction was proposed for some elements of wind resistant characteristics, i.e. residential house, number of stories, configuration of roof, material of claddings and material of roof.

Damage indicators for the estimation of gust wind speed were examined in order to evaluate the intensity of tornado or downburst and so on. This aims to contribute the establishment of Japanese Enhanced Fujita Scale for the good estimation of the strong wind damage by tornado or downburst. Degrees of damage were proposed for some construction's elements and an example for a damage indicator, "standard Japanese roof with ceramic tiles", was presented.

In order to evaluate the impact of missiles caused by tornado, a study on the velocity prediction of flying debris in a tornado-like vortex was carried out by numerical simulation. A series of unsteady flow fields of a tornado-like vortex was generated by Large Eddy Simulation. The aerodynamics of debris was examined and the range of aerodynamic parameters of debris resulting building damage was investigated. The trajectories of flying debris and the statistical distributions of the maximum speed of debris were obtained in various conditions i.e. the release height and the aerodynamic parameter of debris, the maximum tangential wind speed, the radius of maximum tangential wind speed and the traveling speed of tornado. Relation between the maximum ground speed of debris and the maximum wind and traveling speed of tornado was obtained as a function of aerodynamic parameter of debris.

The characteristics of flying debris in the tornado occurred in Tsukuba-city on May 6, 2012 was numerically investigated. The trajectories of flying debris were calculated using numerically generated unsteady turbulent wind fields of tornado-like vortex. The ground speeds of flying debris were obtained with the variety of the strength, the scale and the moving speed of tornado measured from the visual records such as videos or photos. The calculated maximum ground speeds of debris show good accordance with the measured values.

Outline of the damage due to tornados occurred in North Kanto Area, Japan on May 2012 was reported. The meteorological environment of the supercell thunderstorms from which the tornadoes developed and the wind characteristics of the vortices in the tornados are presented. The disaster was mainly reported from the view point of damage to residential buildings. A survey of the human casualty and behavior of victims was also described briefly.

本研究では，強風による飛散物に対する外装材の耐衝撃性能の試験・評価方法を策定する資料とするため，日本における代表的な飛散物である和瓦を加撃体として用いた試験を行い，ISO 16932に規定された評価方法に準じて合わせガラスの耐衝撃破壊特性を明らかにした。さらに，瓦の衝撃力を不貫通速度の大きさとして評価するとともに，ISO 16932に規定された加撃体に対して瓦の衝撃力と等価な衝突速度を求め，瓦の衝撃力を評価できるようにISO規格と整合性のとれた標準加撃体を提案した。, Impact resistant test of glazing was carried out by using a newly developed air-cannon, that is a missile-propulsion device. Resistant and failure characteristics of laminated glass were investigated by roof tile missile. A series of tests was carried out by varying the impact speed, the kind of roof tile, the impact location of roof tile and the location of the glass where impacted. The results were compared with the specification of ISO16932 and the reference missile for the standard impact test in Japan was proposed.

本研究では, ISO規格(ISO 16932)に規定された建物開口部におけるガラスの耐衝撃破壊性能評価方法に従って衝撃試験を行うことのできる試験装置を作成し, 種々の板ガラスを試験体として用いた衝撃試験を行い, 耐衝撃破壊性能を明らかにした。得られた結果をまとめると, 今回試験体として用いた普通フロートガラス(厚さ5, 6, 8, 10, 12mm), 強化ガラス(厚さ5, 6, 8, 10mm), 網入りガラス(厚さ6.8, 10mm)は, ISO規格に従う判定に不合格であった。合わせガラス(中間膜の厚さ30, 60, 90milの３種類とガラス厚さ3, 5mmの２種類の組み合わせ)ではISO規格に従う加撃体Ａ, Ｂ, Ｃによる, フィルム貼りガラス(フィルム厚さ50, 100, 350, 450μmの４種類とガラス厚さ5, 6mmの2種類の組み合わせ)では加撃体Ａ, Ｂによる衝撃試験に合格した。, Impact resistant test of glazing was carried out based on ISO 16932. An air-cannon, that is a missile-propulsion device, for the impact resistant test of cladding against windborne debris was manufactured. A series of tests of various kinds of glasses was carried out to investigate the performance of impact resistant and the characteristics of failure. The performance of sheet glasses, such as float, tempered, wired, laminated and filmed glasses was evaluated by the specification of ISO16932.

竜巻の渦内の気流性状や渦と物体との相互作用を明らかにすることを目的に，数値計算手法を用いて竜巻状の渦の作りだす数値シミュレーターを作成し，計算条件を変化させて，種々の形態をもった竜巻状の渦を作り出した。本報では，作り出された渦の生成条件や渦内の気流性状について報告する。, A numerical tornado simulator was developed and a tornado-like vortex was generated numerically by Large Eddy Simulation. The tornado simulator consists of a convection region and a convergence region. A series of unsteady flow fields of vortex were generated and examined the flow characteristics with varying the inflow conditions, the boundary conditions, and the configuration of calculating domain. Some of the typical vortices ; single core type without mean down flow region in the core, single core type with mean down flow region in the core, multiple core type and swirling core type were presented. The flow characteristics of the single core type with mean down flow region in the core were examined. The common future of these vortices was summarized as, 1. The differential pressure ? P from the surrounding mean pressure decreases to the value of 2?P/ρV2tmax=-1.5 at the position where the maximum tangential wind speed occurs, where is ρ the air density, Vtmax the maximum tangential wind speed. 2. The tangential wind speed decreases to the half of Vtmax at three times of the maximum tangential wind speed radius.

本研究では，日本における建築物外装材の耐衝撃性能の標準仕様や試験方法の策定に資するため，高速で飛来する飛散物を模擬する加撃体を射出し，外装材の耐衝撃試験を行うためのエアーキャノンを作製した．エアーキャノンの設計にあたっては，アメリカ合衆国やISO基準に準ずる耐衝撃性能試験を行えるようにした．本報告では，外装材の耐衝撃性能を評価する既存の試験・評価方法を概説するとともに，作製した装置の性能試験結果について述べる, We manufactured an air-cannon, that is a missile-propulsion device, for the impact resistant test of cladding against windborne debris. The air-cannon consists of a compressed-air supply, pressure control and release valves, a barrel, a support frame and a speed-measuring system. Sets of photoelectric sensors mounted on the barrel are used for measuring the speed of the missile. The cannon is capable of propelling a missile at a specified speed and orientation towards a specified impact location. We calibrated the speed measuring system by a high-speed video camera. The fastest speed was 75m/s for a 3kg lumber. Tolerances for the measured impact speed were satisfied the specification of ISO16932.

2008年7月27日12時50分頃，福井県敦賀市敦賀湾に面した浜辺で突風が発生し，イベント用大型テントが吹き飛ばされ，死者1名，負傷者9名の被害が発生した。この突風は日本海で発達した低気圧の通過に伴うガストフロントが原因であると推測された。吹き飛ばされたテントは幅40m×奥行き10m×軒高さ約3mで，海に面した壁面以外の3面がテント生地で塞がれていた。テントには約4, 800kgの重石が繋がれていたが，海から吹いてきた風がテントの中に入ると，テントが重石とともに約10m吹き飛ばされた。風洞実験を行ってテントの風力係数を求め，その結果を用いてテントの飛散風速を推測した。重石が繋がれたテントは，壁を塞がない場合には瞬間風速約22m/sまで転倒しないが，3壁面を塞ぐと瞬間風速約10m/sで転倒することがわかった。, A sudden severe storm destroyed a large tent structure connected to some concrete weight cubes, at near coast in Tsuruga City, Fukui Prefecture. High wind accompanied with the gust-front in the storm killed a man and injured nine persons. While the tent structure had an opening faced to sea, it was covered on remained walls with canvas. In this situation, when wind attacked from the open face, the tent would be easily lifted up, even though some weights might fairly resist to the lift caused by wind. This study describes the observation of damage to the tent structure and wind tunnel test results, which was carried out to quantify the wind load when the tent will be blown off in various situations of wall coverings.

上部に吸い出し口をもつ円筒形の対流域と，下部に正方形水平断面の直方体収束域をもつ竜巻発生装置を模擬した解析領域を設定し，ラージ・エディ・シミュレーション(ＬＥＳ)を用いた数値計算によって竜巻状の渦を生成した。流入気流条件，解析領域の大きさや形状等が渦の発生条件や渦内の気流性状に及ぼす影響を明らかにした。さらに，渦内の低圧部の分裂も見られるなど，種々の竜巻状の渦を再現し，今回用いた計算手法が，実際の竜巻内の気流性状を検討するツールとしての可能性を示した。, A tornado-like vortex was generated numerically by Large Eddy Simulation. The calculation region was designed to reproduce the wind flow in a tornado simulator. The tornado simulator consists of a convection region and a convergence region. An unsteady flow field of vortex was generated and examined the flow characteristics with varying the inflow conditions and the configuration of calculating region.

第21回大気圏シンポジウム（2007年2月27日-28日. 宇宙航空研究開発機構宇宙科学研究本部（JAXA)(ISAS)）, 相模原市, 神奈川県, 21st Atmospheric Science Symposium (February 27-28, 2007. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)), Sagamihara, Kanagawa Japan, 資料番号: SA6000129032

2006年には台風や竜巻，突風による建物強風被害が多発した。とくに，9月の台風13号では八重山諸島や九州において多くの建物が強風被害を受けた。また，同台風は多くの竜巻や突風を伴い，延岡市の竜巻では3名の死者を出し，ＪＲ日豊本線の特急"にちりん"が脱線した。本報では，これら台風0613号による建物の強風被害を中心に，その特徴を検証し，防災・減災の観点から建物の耐風性能を高めることが必要であることを明らかにした。具体的な対策としては，1：屋根葺き材，屋上の設置物等の飛散を防ぐこと。2：雨戸や格子，耐風性能の高いガラスを用いるなど，飛散物に対する防備を高めること。また，3：軽量建物用の耐風設計を整備することが至急の課題であること。等である。, We had many strong wind disasters caused by typhoon, tornados and down bursts in 2006. Typhoon 0613 in September struck Yaeyama Islands, Japan, and significant damage to buildings and houses occurred. In Kyusyu, there was many damage to houses and buildings especially in Nagasaki, Saga and Hukuoka prefectures. This typhoon also brought a number of strong winds and a tornado that struck Nobeoka city in Myazaki prefectures. Three persons were dead and a train was derailed. This paper focuses on the characteristics of the damage to buildings and houses caused by strong wind of Typhoon 0613 and examined effective measures from the viewpoint of preventing and mitigating these disasters. To prevent the claddings and openings from the flying missiles is important to reduce the strong wind damage. The shutters and the wind resistant glasses are effective. To decrease the number of missile is also essential. The damage caused by lightweight houses is notable in urban area.

組合せ最適化問題を効率良く解く進化的計算手法の1つに,確率的スキーマ貪欲法(Stochastic Schemata Exploiter: SSE)がある.SSEは,母集団に多様性を持たせることで,優れた収束特性を維持したまま大域的探索能力が向上する可能性がある.そこで,本論文ではSSEの世代交代モデルを改良したCross generational elitist selection SSE(cSSE)を提案する.さらに,0/1組合せ最適化問題において,SSE,cSSEをMinimal Generation Gap(MGG)に基づくGA,Bayesian Optimization Algorithm(BOA)と性能比較を行い,それらの探索性能を検討する.その結果,cSSEは優れた収束特性と大域的探索能力を有していることが分かった., The Stochastic Schemata Exploiter (SSE) is one of the evolutionary optimization algorithms for solving the combinatorial optimization problems. The SSE can improve the global search ability by maintaining the diversity of the population. In this paper, we present the Cross generational elitist selection SSE (cSSE) algorithms which improves the generation alternation model of the SSE. The SSE and the cSSE are compared with the GA with the Minimal Generation Gap (MGG) and the Bayesian Optimization Algorithm (BOA) in 0/1 combinatorial optimization problem in order to discuss their convergence property. As a result, we indicate that cSSE has an excellent convergence property and the global search ability.

組合せ最適化問題に対する進化的計算手法の1つに確率的スキーマ貪欲法(Stochastic Schemata Exploiter: SSE)がある.本論文では,スキーマの関係に着目してSSEを改良した拡張型確率的スキーマ貪欲法(Extended Stochastic Schemata Exploiter: ESSE)を提案する.また,0/1組合せ最適化問題において,SSEとESSEをMinimal Generation Gap (MGG)やBayesian Optimization Algorithm (BOA)と性能比較を行い,それらの探索性能を検討する., Stochastic Schemata Exploiter (SSE) is one of the evolutionary optimization algorithms for solving the combinatorial optimization problems. Next, we present the Extended SSE (ESSE) algorithms which are composed of the original SSE and new ESSE operations. The SSE and the ESSE are compared with the Minimal Generation Gap (MGG) and the Bayesian Optimization Algorithm (BOA) in 0/1 combinatorial optimization problem in order to discuss their convergence property.

第20回大気圏シンポジウム（2006年2月23日-24日. 宇宙航空研究開発機構宇宙科学研究本部（JAXA)(ISAS)）, 相模原市, 神奈川県, 20th Atmospheric Science Symposium (February 23-24, 2006. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)), Sagamihara, Kanagawa Japan, 資料番号: SA6000130050

台風0418号が通過した際に，厳島神社周辺では地形性の強風が発生し各種被害が起きた。また，過去にも同じようなコースを台風が進むときに，同様な被害を受けたことが報告されている。本報では，このような地形性の強風の実態を解明するために，数値シミュレーションにより台風通過時の厳島神社周辺における強風場を再現した。その際，メソスケールの気象場を解析できるPSU/NCAR MM5，および，LESを用いた狭域スケールの非定常・非線形風況シミュレータRIAM-COMPACTを用いた。計算結果は実測値や被害の調査結果と比較し，精度や境界条件の与え方等，計算を行う際の問題点について検討を行った。また，計算結果から求めた最大風速分布は，建物や人的被害の分布と良く対応しており，強風被害予測の可能性を示した。, The strong wind fields around Miyajima in Hiroshima Bay were simulated numerically during Typhoon Songda in 2004. The PSU/MM5 model was used for the calculation of meso-scale regions. The strong wind that passed over the sea and blew into the Hiroshima Bay was simulated. The predicted wind fields were examined comparing with the observed records and the field investigation of damage to the human and buildings. The calculated maximum wind speed map was well correlated to the distribution of damage rate by strong wind in Hiroshima Prefecture. Unsteady wind fields were also computed by Large Eddy Simulation in the fine region around Miyajima. The local wind characteristics caused by the topography around Itsukushima Shrine were investigated. The down flow along the valley to the south of the shrine was simulated in the neutral atmospheric condition. The local wind flows around the shrine were discussed.

本報告は，異常気象を引き起こす原因の解明と，それによってもたらされる災害の実態について述べたもので3部からなっている。第1部では，気象庁現業の数値天気予報モデルを用いて，熱帯大気中の季節内振動のアンサンブル予報に適した摂動を生成するように，成長モード育成法の改良を行った結果について述べている。得られた初期摂動は，位相速度が約30 m/sで東進する，対流とは結合しない，東西波数1のKelvin 波と良く似た空間構造を持っていることが示された。摂動の成長率は，中高緯度における傾圧不安定にくらべ大変小さいことがわかった。第2部では，強風特性を明らかにし，強風による被害予測の用に供するために，2004年の台風18号を解析対象として，厳島神社周辺の複雑な地形上における台風通過時強風の再現を数値計算により試みた結果について述べている。地形を再現できる程度の詳細な解析領域を使用した．計算にはメソスケールの気象場を解析できるPSU/NCAR MM5，および，ＬＥＳを用いた狭域スケールの非定常・非線形風況シミュレータRIAM-COMPACTを用いた。第3部では，2005年からデータの取得可能となったFY2Cの衛星画像データの精度を，MTSATのデータと比較することによって検証するとともに，FY2Cデータの補正方法を検討した結果について述べた。, This paper describes the analysis of various phenomena related with anomalous weather and its hazards, which consists of three parts. The first part describes a new method for obtaining initial perturbations appropriate to the ensemble forecast of the intraseasonal variability in the tropics, which was developed using the operational numerical weather forecast system of the Japan Meteorological Agency. The obtained initial perturbations have spatial structure similar to eastward propagating dry Kelvin wave with phase speed of 30 m/s. The second part shows a numerical method to simulate strong wind fields over complex topography during typhoon. For investigating the strong wind characteristics and predicting wind hazards. The PSU/MM5 and LES were used for the calculation of meso and micro-scale unsteady wind fields. The last part describes the results of the analyses using FY”C data for the research and prediction of Japanese abnormal weather, especially in Baiu season, which came into official operation in May, 2005 and observes a wide area of Monsoon Asia extending from Saudi Arabia to Japan from 104E, just above Singapore.

2004年9月7日に広島県の厳島神社を襲った台風18号による被害について，現地調査を行い，厳島神社および周辺の被害や強風に関する各種データを集めた．それらの資料をもとに，当時の気象状況および被害の実態について明らかにした．厳島神社では本社拝殿，西回廊，客神社祓殿などの檜皮屋根のめくれ，能舞台の軒瓦の飛散などが強風による被害であった．また，回廊や平舞台，高舞台，火焼前，左楽房などが高潮と波によって被害を受けた．さらに，神社南側に延びる谷筋に沿って吹き降りる強風が被害状況や目撃証言などにより確認された．, Typhoon 0418 struck Miyajima Island, in the prefecture of Hiroshima, Japan, on September 7, 2004. There was a maximum peak gust of 60.2m/s which was the strongest wind ever recorded by theHiroshima Local Meteorological Observatory. Itsukushima Shrine, a designated world heritage site onMiyajima Island, suffered various kinds of damage. We conducted a field investigation immediatelyfollowing the typhoon. The wind environment and the damage to the shrine as well as to the surroundingarea were investigated and will be described in this report.

本報告は，異常気象を引き起こす原因の解明と，それによってもたらされる災害の実態について述べたもので3部からなっている。第1部では， 2001年12月に生じた成層圏突然昇温現象(Stratospheric Sudden Warming; SSW) の予測可能性を調べ，SSW は2週間以前から予測可能であり，SSW発生期には予測の初期値に対する鋭敏性が極めて大きくなることを見出した。第2部では，2004年9月7日から10日にかけて日本列島を縦断し，各地に多大な被害をもたらした台風0418号による強風被害について，世界遺産である宮島の厳島神社における現地被害調査を中心に，気象状況や被害状況等を解析した結果について述べている。, This paper describes the analysis of various phenomena related with anomalous weather and its hazards, which consists of three parts. Predictability and a possible tropospheric precursor of a zonal-wavenumber (WN) 1 stratospheric sudden warming (SSW) event occurring in December 2001 are examined in the first part, using all ensemble members of the 1-month forecasts carried out by the Japan Meteorological Agency (JMA). The second part shows the field investigation on the severe damages of structures including Itsukushima Shrine, a designated world heritage site on Miyajima Island in the prefecture of Hiroshima, Japan, induced by the typhoon 0418 which attacked on September 7, 2004. The last part show the results of several analyses, which were carried out to investigate abnormal typhoons hit Japanese territory in 2004. The seasonal march of the sea surface temperature (SST) were investigate and reproduce the meteorological situation by using a mesoscale numerical model. The Asian monsoon is also investigate to understand the abnormal weather in summer

The demand of numerical prediction of wind flow over rough surfaces such as urban areas is increasing. Reproduction of the roughness configuration in the mesh discretization is a direct way for numerical calculations. However, the roughnesses near the ground such as buildings or houses are complicated. Therefore the reproduction increases the computational load and can cost a lot of time and money. In order to reduce this, we applied a filtering operation, that is an averaging in a space containing solid obstacles, to the Navier-Stokes equations and derived filtered equations with a subgrid scale turbulent modeling for the Large Eddy Simulation. Consequently, we can take the obstacles to be porous media distributed uniformly in the mesh. The configuration of the obstacles does not need to be reproduced any further. We can calculate the space-averaged property of flows with coarse meshes and a reduced computational load. We present some calculations of turbulent boundary layer over a rough surface. The performance and effectiveness of the calculation method are examined by comparing with the measured data by wind tunnel experiments.

2003年9月10日から11日にかけて宮古島を襲った台風14号は，その進路が宮古島を通過後，北上して韓国に向かったこともあり，日本における被害は宮古島に集中した。中心が宮古島の近くを通過した際には，宮古島地方気象台で最大瞬間風速74.1m/sが記録され，強風による災害を中心に多くの被害が発生した。台風の気象学的な性質は(その1)に示したとおりで，ここではその被害の特性および復旧状況等について現地調査をもとにまとめる。調査結果からは，飛散物の低減，飛来物からの防備，ガラス片による怪我の防止が強風被害の低減に効果があること，電柱の折損防止，風力発電用の風車および塔の耐風設計基準の見直しが必要であること等を明らかにした。, Typhoon 0314 struck Miyako Island, Japan, during September 10 and 11, 2004. The maximumpeak gust of 74.1m/s has been recorded, which is the 7th strong wind ever recorded at weather stations inJapan. Significant damage occurred throughout the island. We had field investigations just after theattack of typhoon and about two months later. Various kind of damage, such as buildings, infrastructuresand agricultural products were studied and some lessons were summarized.

資料番号: AA0046920024

建築構造物に加わる風圧特性を調べるために，接地境界層内に設置された立方体模型まわりの風速・風圧の多点同時計測を行った。得られた観測データをもとに接近流の気流性状および立方体模型に加わる風圧性状を明らかにした。接近流の気流性状に関しては，平均，分散，スペクトル，相関等，各種統計量を求め，乱流特性を明らかにした。さらに，接近流の風速変動と立方体模型に加わる風圧変動の相関を調べ，接近流が風圧変動に及ぼす影響について明らかにした。, This study presents the results of an experiment where a field measurement was arranged using a 2.4m cubelocated on the ground and a number of anemometers arrayed around it. The characteristics of approaching flowsare described and the velocity-pressure correlations are discussed .

1999年9月24日に九州地方を縦断した台風9918号は, 熊本県鹿島村で最大瞬間風速83m/sを記録するなど, 各地で記録を更新する強風が吹き, 八代海沿岸地域で高潮による死者12人を含む甚大な人的・建物・鉄塔・農林被害をもたらした, 本報では現地調査および航空機による空からの被害調査を行い, 建物の被害状況や航空機からの映像によるシート率の分布を求め, 建物被害率との関係を検討した, また, 建物被害率と気圧場から推定した風速との関係も求めた., The damage of buildings and houses by Typhoon 9918 along Yatsusiro Sea was studied. The damage rate of buildings and houses was obtained.The sheet rate was also calculated by the aerial photos. The relation of these values was examined.The relation between the damage rate and the maximum gust wind speed was also evaluated.

近畿地方と中部地方にある消防本部の気象観測網を中心して台墨9807号の気象状況を調べた。近畿地方で瞬間風速が50m/secを超える強風域が4ヶ所あり, その発生時刻は最低気圧とほぼ同時の場合と約1時間後の場合に分かれた。合成レーダ図との比較により, 後者の強風は台風の背後にできる降雨帯の周辺で発生し, その風向は台風の回転方向と台風の中心に向かう法線方向に分かれた。その他, 気温, 湿度, 降雨量, 気圧についてこの台風の地上での詳細な気象状況が明らかになった。このように, 台風の地上での気象情報の収集には消防署の細かい気象観測網は大変有用であることが分かった。, Meteorological elements on the Typhoon 9807(Vicki) were investigated using the weather observation network at fire stations in the Kinki and Chubu districts. There were 4 areas in Wakayama, Nara and Mie, where the max instantaneous wind velocities exceeded 50m/sec. In Tanabe City in Wakayama the max instantaneous wind velocity was measured almost simultaneously with the min atmospheric pressure. In the other areas the max instantaneous wind velocity was measured almost one-hour after the min atmospheric pressure occurred. The latter strong winds were expected to be related with a rain band behind the Typhoon 9807.

台風9807号による建物の強風被害調査を行い, 建物の被害分布, 近畿圏の主な歴史的建造物の被害の概要を明らかにした。とくに, 建物の被害が多かった奈良盆地における市町村別の建物強風被害について, 被害把握に対する航空写真の有効性と問題点について検討を行った。その結果, 世帯ごとに求めた建物被害率と航空写真から求めた建物の被害率との間には市街地において良い相関があり, 建物強風災害の把握に有効であることがわかった。, Strong wind damages to buildings and houses by Typhoon 9807 were investigated. The damage rate was obtained from public reports and field investigation. The rate of buildings and houses covered with the sheet shielding from the rain, here we call "sheet rate", was counted by the aerial photos. These two damage rates have a good correlation in the urban area in Nara Basin.

A turbulent flow over a real city：Hiratsuka, was calculated by a refined k-εturbulence model which incorporates the effect of surface roughness using configuration of roughness elements, i.e.buildings and houses. The calculated results were compared with the observed data and examined. The calculation simulates the deceleration of wind speed and the acceleration of the generation of kinetic energy near the ground where the buildings are densely distributed. The high speed wind flow along the river was also calculated.

Using the numerical simulation of the turbulent boundary layer over rough surfaces with a refined k- e turbulence model presented previous paper, a series of calculations were done on the characterized model cities. The change of the mean wind speed and the turbulence intensity due to the configuration of surface roughness was investigated. The variation of the thickness of the boundary layer, the profile of the mean wind speed and the intensity of turbulence against the density of surface roughness, i.e. buildings and houses, was obtained for the wind resistant design.

ドップラーソーダを用いた観測が行われている平塚市において, 粗度形状の影響を取り込むことのできるk一ε2方程式型の乱流モデルを用いて, 市街地上空の気流性状の数値計算を行った。強風時の観測データをもとに計算で発生させた流入境界条件を用いた計算結果は, 実測結果と良い対応を示し, 建物が密集している地域での風速の減少と乱れの増加, 川筋にそった強風域を再現した。, A turbulent flow over a real city: Hiratsuka, was calculated by refined k-ε turbulence model which incorporates the effect of surface roughness using configuration of roughness elements, I.e. buildings and houses. The calculation simulates the deceleration of wind speed and the acceleration of the generation of kinetic energy near the ground where the buildings are densely distributed. The strong wind flow along the river was also calculated.

現在, 建築物周りの非定常乱流場の解析手法としてはラージエディシミュレーション(LES)が有望視されているが, その実用化に際しては流入境界条件の与え方が大きな障害の一つとなっている。本報では条件付確率場の理論を用いた乱流場の生成手法により, 上流側の乱流場を直接計算することなく希望する統計量をもった乱流場を発生させる方法を示す。発生された乱流場は実験結果と比較され, その有効性が確かめられた。, The interpolating method of the flow fluctuation conditioned by the experimental data was introduced. The flow signals at the inlet boundary in the turbulent boundary layer just behind the roughness elements were generated. The flows were interpolated in Fourier space as stochastic processes in a conditional random fields so as to realize the equivalent statistical quantities of experimental results. The digitally generated signals satisfied the statistics up to the second order moments fairly well.The turbulent field just behind the roughness calculated by LES using these inflow conditions was compared with the experimental data and examined.The calculated result shows rather good agreement in mean wind field but the attenuation of wind fluctuation in high frequency caused by the scale of mesh grids was observed.

第27回大気圏シンポジウム（2013年2月28日-3月1日. 宇宙航空研究開発機構宇宙科学研究所（JAXA)(ISAS)）, 相模原市, 神奈川県, 27th Atmospheric Science Symposium (February 28- March 1, 2013. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)), Sagamihara, Kanagawa Japan, 資料番号: SA6000070016, レポート番号: Ⅱ-12

Numerical simulations of the turbulent boundary layer over rough surfaces in the wind tunnel was performed using a refined k-ε turbulence model which can introduce the effect of roughness configuration and volume change of the roughness element. A series of calculations were done on the city models using the optimized drag coefficient and the length scale (termed roughness parameters in this study) for staggered arrayed cubic blocks. Simulated flows showed good agreement with experimental data. Finally, a three-dimensional simulation of wind flow over a real urban city where wind data were observed was carried out. The effectiveness of the simulation method was examined by comparing the calculated result with the field data.

Today the progress of computational calculation gives us some tools to predict wind characteristics around bodies. These are sometimes available for practical use particularly on the study of steady flow. On the other hand the simulation methods of timedependent flow phenomena such as wind fluctuation, eddy motion, vibration of bodies and so on are still in their early stages, but they are very important to know the unsteady turbulent flow.If we want to simulate the unsteady flow in the test section numerically, we need the time series information of wind velocity at the upwind boundary, because the up-wind boundary condition has some effect on the flow field behind. We present the numerical method to generate the fluctuation of streamwise velocity component at the upwind boundary using the measured data.

It is important to know the configuration of the surface roughness, because the wind characteristics in the atmospheric boundary layer near the ground are mainly affected by the surface roughness. Configurations of houses and buildings in real urban cities were obtained from maps and aerial photographs. The relation of the number, the scale and the volume of houses and buildings against the number of stories were evaluated from these data. Using these results, various parameters of roughness configurations against the roughness volume density are examined for real urban areas.

Configurations of buildings and houses in real urban cities were obtained from maps and aerial photographs.The relation of the number, the scale and the volume of houses and buildings against the number of stories were evaluate from these data.Using these results, three model cities which have different characteristics of roughness configuration in the composition of number of stories were generated virtually.The first model city mainly consists of low rise houses up to 3 storied.The second one consists of low rise houses and middle rise buildings up to S storied.The third consists of middle and high rise buildings up to 10 storied.Numerical simulations of wind flows under nutral, strong wind condition over these model cities were carried out.Variations of wind characteristics of turbulent boundary layer with the building density were estimated.The calculated values showed that the mean wind speed decreases, the intensity of turbulence and the virtical gradient of mean wind speed increase when the building density increaes.The variation of these results becomes the largest in case of the second model city which consists of low rise houses and middle rise buildings.Finally predicted values of power law exponent a of the wind speed profiles for the wind resistent desigu were presented against the variation of the building density of these three model cities.

第24回大気圏シンポジウム（2010年2月18日-19日. 宇宙航空研究開発機構宇宙科学研究本部（JAXA)(ISAS)）, 相模原市, 神奈川県, 24th Atmospheric Science Symposium (February 18-19, 2010. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)), Sagamihara, Kanagawa Japan, 資料番号: SA6000073027, レポート番号: Ⅴ-4

The calculation method of three-dimensional flows over rough surfaces was shown. The simulated results were compared with the experimental data in the wind tunnel and the applicability was examined. The configurations of buildings and houses in a real urban city were obtained from a map and a aerial photograph. Numerical calculations of turbulent boundary layer over this urban area were carried out using the three-dimensional simulation method. The calculated values were compared with the observed data at some points in the city. The applicability and the adaptable range were examined by comparing the calculated values with the observed data at some points in the city. Finally the predicted values of wind speed for the wind resistent design were presented using the simulated results and the observed data.

第23回大気圏シンポジウム（2009年2月26日-27日. 宇宙航空研究開発機構宇宙科学研究本部（JAXA)(ISAS)）, 相模原市, 神奈川県, 23rd Atmospheric Science Symposium (February 26-27, 2009. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)), Sagamihara, Kanagawa Japan, 資料番号: SA6000074041, レポート番号: Ⅵ-9

A series of wind tunnel tests were performed to investigate the variation of the surface drag caused by different array patterns of roughness elements. The drag on the rough surface using cubic blocks was directly measured by a float built in the floor of the wind tunnel. The direct measurement by the float was comparablly reliable when compared with other three different ways of drag measurement. The variation of the surface drag coefficient Cr caused by array patterns has been examined. The relationship between Cr and the 'roughness concentration' ratio λ element frontal area/surface area per element, showed that the randomarrayed distribution was equivalent to the staggered arrayed pattern with the elements facing to the wind at an angle of 45°

Evaluation of roughness parameters was performed in order to simulate the turbulent boundary layers over rough, random surfaces such as urban areas.The variation of roughness parameters for the turbulence model against the roughness volume density was examined for staggered arrayed cubic blocks. A number of calculations were carried out to simulate the turbulent boundary layers over various city models using the values of roughness parameters for the cubic blocks. Farely good agreements between numerical results and experimental data shows the applicability of the roughness parameters for staggered arrayed cubic blocks to the urban areas.