Clarification of Generation Mechanism for Transient Fluid-induced Forces on Bluff Body due to Gusty Wind

• Project/Area Number: 21360213
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Structural engineering/Earthquake engineering/Maintenance management engineering
• Research Institution: Kyoto University
• Principal Investigator: SHIRATO Hiromichi 京都大学, 大学院・工学研究科, 教授 (70150323)
• Co-Investigator(Kenkyū-buntansha): YAGI Tomomi 京都大学, 大学院・工学研究科, 准教授 (30293905)
• Project Period (FY): 2009 – 2011
• Project Status: Completed (Fiscal Year 2011)
• Budget Amount: ¥18,070,000 (Direct Cost: ¥13,900,000、Indirect Cost: ¥4,170,000); Fiscal Year 2011: ¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000); Fiscal Year 2010: ¥4,160,000 (Direct Cost: ¥3,200,000、Indirect Cost: ¥960,000); Fiscal Year 2009: ¥9,490,000 (Direct Cost: ¥7,300,000、Indirect Cost: ¥2,190,000)
• Keywords: 風工学 / 過渡流体力 / 非定常空気力 / 瞬発気流 / 突風 / 竜巻 / 矩形断面 / 5本円柱

Research Abstract

An experimental setup which can reproduce lateral wind was newly manufactured and was used for the measurement of transient lift force on a square prism running along a guide rail. Some relationship to Karman vortex shedding was implied. The difficulty to identify each force component was also pointed out.
Transient aerodynamic forces on a square prism and a group of 5 circular cylinders were measured by use of another existing wind tunnel which can also generate sudden increase of longitudinal wind velocity. It was found that the asymmetric generation of separation bubbles on both side surfaces was important for the mechanism of transient lift on a square prism. And the complex flow pattern around the 5 circular cylinders was found to determine the transient forces. The transient forces were well reproduced by CFD simulation which showed an evidence of relationship with Karman vortex. A simulation of time history of gusty wind due to an ideal tornado was conducted to discuss safety evaluation of a train wagon during tornado passage nearby.

Research Products

• [Journal Article] Flow Around a 2-D Bluff Body with Increasing Wind Velocity in Short Time Duration (2011)
  • Author(s): Hiromichi Shirato, Osamu Sasaki, Kenji Inage
  • Journal Title: Proceedings of the 11th Asian Symposium on Flow Visualization Volume: ASV11-99-10
  • Peer Reviewed
• [Journal Article] 突風作用下の柱状構造物の非定常空気力 (2011)
  • Author(s): 白土博通, 佐々木治, 稲毛健至
  • Journal Title: 第60回理論応用力学講演会講演論文集 Volume: OS16-07
  • NAID: 130004604736
  • Peer Reviewed
• [Journal Article] 風速急変時における近接5本円柱の空力特性に関する研究 (2011)
  • Author(s): 稲毛健至, 白土博通, 八木知己, 佐々木治
  • Journal Title: 日本風工学会誌 Volume: vol.36, No.2 Pages: 173-174
  • NAID: 10028288428
• [Journal Article] 非定常空気力特性の実験的解明-その2 2次元角柱に作用する非定常空気力特性- (2010)
  • Author(s): 白土博通, 前田耕治, 加藤嘉昭, 高杉祐仁, 佐々木治
  • Journal Title: 日本風工学会誌 Volume: 第35巻第2号 Pages: 130-138
  • NAID: 10026446755
• [Journal Article] Study on Aerodynamic Forces of Basic Structural Sections by Gusty Wind (2010)
  • Author(s): Hiromichi Shirato, Yuichi Sato, Osamu Sasaki, Do Van Bao
  • Journal Title: Proceedings of the 23rd KKCNN Symposium on Civil Engieering Pages: 229-232
• [Journal Article] 突風発生時における構造基本断面作用する空気力に関する実験的研究 (2010)
  • Author(s): 佐々木治, 白土博通, 加藤嘉昭
  • Journal Title: 第21回風工学シンポジウム論文集 Pages: 191-196
  • Peer Reviewed
• [Journal Article] 非定常空気力特性の実験的解明 -その2 2次元角柱に作用する非定常空気力特性- (2010)
  • Author(s): 白土博通, 前田耕治, 加藤嘉昭, 高杉祐仁, 佐々木治
  • Journal Title: 日本風工学会誌 Volume: 第35巻第2号 Pages: 130-138
  • NAID: 10026446755
• [Journal Article] Coherent structure of surface pressures on 2-D rectangular cylinders (2010)
  • Author(s): Hiromichi Shirato, Yuichi Sato, Osamu Sasaki, Do Van Bao
  • Journal Title: Proceedings of the 5^<th> International Conference on Computational Wind Engineering
  • Peer Reviewed
• [Journal Article] Study on Aerodynamic Forces of Basic Structural Sections by Gusty Wind (2010)
  • Author(s): Hiromichi Shirato, Yuichi Sato, Osamu Sasaki, Do Van Bao
  • Journal Title: Proceedings of the 23^<rd> KKCNN Symposium on Civil Engineering Pages: 229-232
• [Journal Article] Transient Drag Force on 2-D Bluff Bodies under Gusty Wind Condition (2009)
  • Author(s): Hiromichi Shirato, Kohji Maeta, Yoshiaki Kato and Yuji Takasugi
  • Journal Title: Proceedings of the 7th Asia-Pacific Conference on Wind Engineering Pages: 258-264
  • Peer Reviewed
• [Journal Article] Transient Drag Force on 2-D Bluff Bodies under Gusty Wind Condition (2009)
  • Author(s): H.Shirato, K.Maeta, Y.Kato, Y.Takasugi
  • Journal Title: Proceedings of the 7^<th> Asia-Pacific Conference on Wind Engineering Pages: 258-264
  • Peer Reviewed
• [Presentation] Aerodynamic characteristics of live cylinders in proximity under wind velocity increase in short time duration (2011)
  • Author(s): Hiromichi Shirato, Osamu Sasaki, Kenji Inage
  • Organizer: the Twenty-Fourth KKCNN Symposium on Civil Engineering
  • Place of Presentation: 淡路夢舞台国際会議場
  • Year and Date: 2011-12-14
• [Presentation] Transient aerodynamic forces on structural members due to sudden increase of wind velocity (2011)
  • Author(s): Hiromichi Shirato, Osamu Sasaki, Kenji Inage
  • Organizer: Research Seminar on Full-Scale Monitoring for Wind Disaster Mitigation
  • Place of Presentation: Kyoto University
  • Year and Date: 2011-11-03
• [Presentation] 近接5本円柱の風速急変時における空力特性に関する研究 (2011)
  • Author(s): 稲毛健至, 白土博通, 八木知己, 佐々木治
  • Organizer: 土木学会第66回年次学術講演会
  • Place of Presentation: 愛媛大学
  • Year and Date: 2011-09-07
• [Presentation] 風速急変時における排気筒断面の空力特性に関する基礎的研究 (2011)
  • Author(s): 稲毛健至, 白土博通, 八木知己, 佐々木治
  • Organizer: 平成23年度土木学会関西支部年次学術講演会
  • Place of Presentation: 関西大学
  • Year and Date: 2011-06-12
• [Presentation] Transient aerodynamic forces on 2-D five circular cylinders in a group due to short-rise-time gust (2011)
  • Author(s): Hiromichi Shirato, Osamu Sasaki, Kenji Inage
  • Organizer: 5th International Symposium on Wind Effects on Buildings and Urban Environment Wind Hazard Resilient Cities : New Challenges
  • Place of Presentation: Tokyo
  • Year and Date: 2011-03-08
• [Presentation] Transient aerodynamic forces on 2-D five circular cylinders in a group due to short-rise-time gust (2011)
  • Author(s): Hiromichi Shirato, Osamu Sasaki, Kenji Inage
  • Organizer: 5th International Symposium on Wind Effects on Buildings and Urban Environment Wind Hazard Resilient Cities : New Challenge
  • Place of Presentation: Tokyo
  • Year and Date: 2011-03-08
• [Presentation] 風速急変時における構造断面に作用する過渡空気力に関する基礎的研究 (2010)
  • Author(s): 佐々木治, 白土博通, 八木知己, 加藤嘉昭
  • Organizer: 土木学会第65回年次学術講演会
  • Place of Presentation: 北海道大学
  • Year and Date: 2010-09-01
• [Presentation] Transient Aerodynamic Forces due to Gusty Wind (2010)
  • Author(s): Hiromichi Shirato, Koji Maeta, Yoshiaki Kato, Yuji Takasugi, Osamu Sasaki
  • Organizer: The 3rd Asia Bridge Summit
  • Place of Presentation: Shanghai, China
  • Year and Date: 2010-08-07
• [Presentation] Transient Aerodynamic Forces due to Gusty Wind (2010)
  • Author(s): Hiromichi Shirato, Koji Maeta, Yoshiaki Kato, Yuji Takasugi, Osamu Sasaki
  • Organizer: The 3^<rd> Asia Bridge Summit
  • Place of Presentation: Shanghai, China(招待講演)
  • Year and Date: 2010-08-07
• [Presentation] Growth Mechanism of Drag Force due to Gusty Wind in Tornadoes (2009)
  • Author(s): H.Shirato, Y.Kato, K.Maeta, Y.Takasugi
  • Organizer: 第22回土木工学に関するKKCNNシンポジクム
  • Place of Presentation: タイ・チェンマイ
  • Year and Date: 2009-10-31
• [Presentation] 構造基本断面の overshoot 現象に関する研究 (2009)
  • Author(s): 加藤嘉昭, 白土博通, 前田耕冶, 高杉祐仁
  • Organizer: 第64回土木学会年次学術講演会
  • Place of Presentation: 福岡大学七隈キャンパス
  • Year and Date: 2009-09-02
• [Presentation] 突風発生時における構造基本断面のovershoot現象に関する研究 (2009)
  • Author(s): 加藤嘉昭, 白土博通, 前田耕冶, 高杉祐仁
  • Organizer: 平成21年度日本風工学会年次研究発表会
  • Place of Presentation: 日本大学理工学部
  • Year and Date: 2009-05-27
• [Presentation] 突風発生時における構造基本断面の overshoot 現象に関する研究 (2009)
  • Author(s): 加藤嘉昭, 白土博通, 前田耕冶, 高杉祐仁
  • Organizer: 平成21年度日本風工学会寝年次研究発表会
  • Place of Presentation: 日本大学理工学部
  • Year and Date: 2009-05-27
• [Presentation] 風速急変時における構造基本断面の overshoot 現象に関する基礎的研究 (2009)
  • Author(s): 加藤嘉昭, 白土博通, 前田耕冶, 高杉祐仁
  • Organizer: 平成21年度土木学会関西支部年次学術講演会
  • Place of Presentation: 神戸市立高等専門学校
  • Year and Date: 2009-05-23