• Search Research Projects
  • Search Researchers
  • How to Use
  1. Back to previous page

Gas Exchange Mechanism in Conducting Airways of Human Lung

Research Project

Project/Area Number 13450080
Research Category

Grant-in-Aid for Scientific Research (B)

Allocation TypeSingle-year Grants
Section一般
Research Field Thermal engineering
Research InstitutionTokyo University of Agriculture and Technology

Principal Investigator

MOCHIZUKI Sadanari  Tokyo Univ. of Agriculture and Technology, Faculty of Engineering. Professor, 工学部, 教授 (10013715)

Co-Investigator(Kenkyū-buntansha) MURATA Akira  Tokyo Univ. of Agriculture and Technology, Faculty of Engineering, Associate Professor, 工学部, 助教授 (60239522)
Project Period (FY) 2001 – 2002
Project Status Completed (Fiscal Year 2002)
Budget Amount *help
¥13,600,000 (Direct Cost: ¥13,600,000)
Fiscal Year 2002: ¥3,900,000 (Direct Cost: ¥3,900,000)
Fiscal Year 2001: ¥9,700,000 (Direct Cost: ¥9,700,000)
KeywordsReciprocating Flow / Branching Tube / Flow Separation / Mass Transport / Flow Visualization / Finite volume Method
Research Abstract

The airway of the human lung consists of a very complicated branching tube network. At each bronchus, the airways repeat branching with their average diameter and the length decreasing. At the end of airways, numerous alveoli that exchange carbon dioxide for oxygen exist. As for the gas transport in the conducting airways, a lot of researches have been done. However, the mechanism how the fresh air, which was inhaled in the inspiration process, reaches alveoli is not known well yet. Recently, the authors revealed that bi-directional axial gas-exchange phenomenon occurring in the conducting airways of human lung system was governed by "trap-and-release" mechanism caused by "generation-and-extinction" of flow-separation regions.
In order to further examine the phenomena occurring in the real human lung, three-dimensional test sections were newly constructed in addition to the two-dimensional one. Flow visualization experiments and numerical analysis in reciprocating flow inside a multi-ge … More neration branching-tube network were performed. In the experiments, the followings were revealed : (1) Even in the 3-D test section, "trap-and-release" mechanism played an important role. (2) In the 3-D test section, asymmetric flow in the ancestor tube results in the different axial mass transport speed depending on the path. (3) The fastest path concerning the axial mass transport changed depending on the geometric configuration decided by the rotation angle between the successive branches.
In the numerical analysis, the finite volume method was used, and a two-dimensional branching case was computed with three different branching angles. In the numerical results, the relation between the size of the flow-separation bubble and axial mass transport was observed. The relation was not monotonic, and therefore there must be an optimal branching angle. By examining the flow field in detail, it was observed that the flow-separation bubble had two effects on the mass transport enhancement : the "trap-and-release" effect and the acceleration of the fluid bv reducing the cross-sectional area of the flow passaee. Less

Report

(3 results)
  • 2002 Annual Research Report   Final Research Report Summary
  • 2001 Annual Research Report
  • Research Products

    (7 results)

All Other

All Publications (7 results)

  • [Publications] 望月貞成, 村田章, 冨樫有紀: "分岐管ネットワークにおける往復流による管軸方向物質輸送(ヒトの肺の誘導気道におけるガス交換機構)"日本機械学会論文集B編. 68・667. 831-838 (2002)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] Mochizuki, S., Jelinkova, O., Murata, A.: "Visualization of Oscillatory Flow in a 3-D Branched-Tube System"CDROM Proc.of the 10th Int.Symp.on Flow Visualization, ISFV10, Kyoto, Aug.26-29. F0173 (2002)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] Mochizuki, S., Jelinkova, O., and Murata, A.: "Visualization of Oscillatory Flow in a 3-D Branched-Tube System"CDROM Proc. of the 10th Int. Symp. on Flow Visualization, ISFV10, Kyoto. F0173. 26-29 (2002)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] Mochizuki, S., Murata, A., and Togashi, Y.: "Axial Mass Transport by Reciprocating Flow in Branching Tube Network (Gas Exchange Mechanism in Conducting Airways of Human Lung)"Trans. of JSME. 68B-667. 831-838 (2002)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] 望月貞成, 村田章, 冨樫有紀: "分岐管ネットワークにおける往復流による管軸方向物質輸送(ヒトの肺の誘導気道におけるガス交換機構)"日本機械学会論文集B編. 68・667. 831-838 (2002)

    • Related Report
      2002 Annual Research Report
  • [Publications] Mochizuki, S., Jelinkova, O., Murata, A.: "Visualization of Oscillatory Flow in a 3-D Branched-Tube System"CDROM Proc. of the 10th Int.Symp.on Flow Visualization, ISFV10, Kyoto, Aug.26-29. F0173 (2002)

    • Related Report
      2002 Annual Research Report
  • [Publications] 望月 貞成, 村田 章, 冨樫 有紀: "分岐管ネットワークにおける往復流による管軸方向物質輸送(ヒトの肺の誘導気道におけるガス交換機構)"日本機械学会論文集B編. (掲載予定). (2002)

    • Related Report
      2001 Annual Research Report

URL: 

Published: 2001-04-01   Modified: 2016-04-21  

Information User Guide FAQ News Terms of Use Attribution of KAKENHI

Powered by NII kakenhi