New wind tunnel experimental method and numerical simulation method of airborne salt to support rational corrosion protection of steel bridges

• Project/Area Number: 23360198
• 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: Nihon University
• Principal Investigator: NOMURA Takashi 日本大学, 理工学部, 教授 (50126281)
• Co-Investigator(Renkei-kenkyūsha): HASEBE Hiroshi 日本大学, 理工学部, 専任講師 (60366565)
• Project Period (FY): 2011-04-01 – 2015-03-31
• Project Status: Completed (Fiscal Year 2014)
• Budget Amount: ¥18,720,000 (Direct Cost: ¥14,400,000、Indirect Cost: ¥4,320,000); Fiscal Year 2014: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000); Fiscal Year 2013: ¥3,120,000 (Direct Cost: ¥2,400,000、Indirect Cost: ¥720,000); Fiscal Year 2012: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000); Fiscal Year 2011: ¥12,740,000 (Direct Cost: ¥9,800,000、Indirect Cost: ¥2,940,000)
• Keywords: 飛来塩分 / 鋼橋 / 防錆 / 風洞実験 / 可視化画像 / 粒子発生器 / 塩分ミスト / 移流拡散解析 / 付着濃度 / 有限要素法流れ解析 / VMS 法 / 可視化実験 / 3次元流れ解析 / 重力効果 / 鋼橋の腐食 / 画像処理 / 濃度分布 / 乱流拡散

Outline of Final Research Achievements

A wind tunnel experimental method has been developed in order to evaluate the advection diffusion behavior of airborne salt and their adhesion to bridge girders. Its three features are: (1) An aerosol generator is place at the inlet of the wind tunnel to obtain uniform concentration distribution in the air streams; (2) The brightness of each pixel of the digital video is transformed to concentration; (3) Several pieces of filter paper are stuck on the experimental model surface, from which the amount of chloride ion is measured. A numerical method is also developed in which the unsteady advection diffusion equation is solved by means of the finite element method. The comparison of the numerical solution with the experimental data shows importance of the turbulent diffusivity and the three dimensional flow simulation for the advection velocity. These experimental method and the numerical simulation method can provide useful information for the corrosion rate of the bridge surface.

Research Products

• [Journal Article] 空気中を落下する球の数値流体解析 (2014)
  • Author(s): 野村卓史，本橋拓磨
  • Journal Title: 第23回風工学シンポジウム論文集 Volume: 23 Pages: 481-486
  • NAID: 130005478182
  • Peer Reviewed / Open Access
• [Journal Article] Image processing technique of smoke flow visualization for the prediction of behavior of airborne sea salt around a bridge girder (2013)
  • Author(s): H. Hasebe, T. Kosugi, S. Hatamoto, T. Kawai, S. Nakayama and T. Nomura
  • Journal Title: Proceedings fo the eighth Asian-Pacific Conference on Wind Engineering Volume: 1 Pages: 1-4
  • Peer Reviewed
• [Journal Article] 有限要素法による正方形角柱周りの煙濃度の移流拡散に関する解析 (2013)
  • Author(s): 長谷部寛，小林丈紘，野村卓史
  • Journal Title: 平成25年度土木学会全国大会第68回年次学術講演会講演概要集 Volume: I
• [Journal Article] 正方形角柱周りの煙濃度の移流拡散に関する有限要素解析 (2013)
  • Author(s): 小林丈紘，長谷部寛，野村卓史
  • Journal Title: 土木学会関東支部第40回技術研究発表会講演概要集 Volume: 40
• [Journal Article] 橋梁まわりの飛来塩分挙動推定のための流れの可視化画像の画像処理法 (2012)
  • Author(s): 長谷部寛，小杉翼，畑元詩音，河合泰斗，中山駿也，野村卓史
  • Journal Title: 第22回風工学シンポジウム論文集 Volume: 22 Pages: 353-358
  • NAID: 130004644508
  • Peer Reviewed
• [Journal Article] 可視化画像の画像処理に基づく橋梁まわりの飛来塩分分布予測法の検討 (2012)
  • Author(s): 小杉翼，畑元詩音，長谷部寛，野村卓史
  • Journal Title: 第67回土木学会年次学術学術講演会講演概要集 Volume: 67
• [Journal Article] 橋梁まわりの飛来塩分付着分布予測のための可視化実験の画像処理法 (2011)
  • Author(s): 長谷部寛, 河合泰斗, 中山駿也, 野村卓史
  • Journal Title: 土木学会年次学術講演会講演概要集 Volume: 66
• [Presentation] Wind tunnel experiment to estimate the amount of airborne sea salt adhered to the surface of a bridge (2015)
  • Author(s): H. Hasebe, Y. Sakakibara, K. Yamaya, R. Sone, Y. Haruki and T. Nomura
  • Organizer: 14th International Conference on Wind Engineering
  • Place of Presentation: Porto Alegre, Brazil
  • Year and Date: 2015-06-21 – 2015-06-26
• [Presentation] Numerical simulation of a falling sphere in air (2015)
  • Author(s): T. Nomura and T. Motohashi
  • Organizer: The 18th International Conference on Finite Element in Flow Problems [FEF2015]
  • Place of Presentation: Taipei, Taiwan
  • Year and Date: 2015-03-18
  • Invited
• [Presentation] Fluid-structure interaction analysis of a falling object in air (2014)
  • Author(s): T. Nomura and T. Motohashi
  • Organizer: The 3rd China-Japan-Korea International Workshop on Wind Engineering [CJK2014]
  • Place of Presentation: Asahikawa, Japan
  • Year and Date: 2014-09-26
• [Presentation] 気流中を落下する物体の解析 (2014)
  • Author(s): 野村卓史，本橋琢磨
  • Organizer: 日本流体力学会年会 2014
  • Place of Presentation: 東北大学
  • Year and Date: 2014-09-16
• [Presentation] 塩分を含むミストを利用した橋梁の飛来塩分付着量予測法の検討 (2014)
  • Author(s): 長谷部寛，榊原佑基，山谷一生，野村卓史
  • Organizer: 土木学会第69回年次学術講演会
  • Place of Presentation: 大阪大学
  • Year and Date: 2014-09-10
• [Presentation] 自由落下する球の構造流体連成解析 (2014)
  • Author(s): 野村卓史，本橋拓磨
  • Organizer: 土木学会第69回年次学術講演会
  • Place of Presentation: 大阪大学
  • Year and Date: 2014-09-10
• [Presentation] An attempt of numerical simulation of flying debris (2014)
  • Author(s): T. Nomura
  • Organizer: Computational Engineering and Science for Safety and Environmental Problems [COMPSAFE2014]
  • Place of Presentation: 仙台
  • Year and Date: 2014-04-14
• [Presentation] The advection diffusion analysis of smoke flows around a body (2014)
  • Author(s): T. Nomura
  • Organizer: Advances in Computational Fluid-Structure Interaction anad Flow Simulation (AFSI 2014)
  • Place of Presentation: Tokyo, Japan
  • Invited
• [Presentation] Image processing technique of smoke flow visualization for the prediction of behavior of airborne sea salt around a bridge girder (2013)
  • Author(s): H. Hasebe
  • Organizer: The eighth Asian-Pacific Conference on Wind Engineering
  • Place of Presentation: Chennai, India
• [Presentation] 有限要素法による正方形角柱周りの煙濃度の移流拡散に関する解析 (2013)
  • Author(s): 長谷部寛
  • Organizer: 平成25年度土木学会全国大会第68回年次学術講演会
  • Place of Presentation: 日本大学生産工学部
• [Presentation] 正方形角柱周りの煙濃度の移流拡散に関する有限要素解析 (2013)
  • Author(s): 小林丈紘，長谷部寛，野村卓史
  • Organizer: 土木学会関東支部第40回技術研究発表会
  • Place of Presentation: 宇都宮大学
• [Presentation] 橋梁まわりの飛来塩分挙動推定のための流れの可視化画像の画像処理法 (2012)
  • Author(s): 長谷部寛，小杉翼，畑元詩音，河合泰斗，中山駿也，野村卓史
  • Organizer: 第22回風工学シンポジウム
  • Place of Presentation: 東京大学山上会館
• [Presentation] 可視化画像の画像処理に基づく橋梁まわりの飛来塩分分布予測法の検討 (2012)
  • Author(s): 小杉翼，畑元詩音，長谷部寛，野村卓史
  • Organizer: 第67回土木学会年次学術学術講演会
  • Place of Presentation: 名古屋大学
• [Presentation] 橋梁まわりの飛来塩分付着分布予測のための可視化実験の画像処理法 (2011)
  • Author(s): 長谷部寛
  • 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: 2011-09-08