Title page for etd-0803112-062732


[Back to Results | New Search]

URN etd-0803112-062732
Author Jia-han Wu
Author's Email Address No Public.
Statistics This thesis had been viewed 5355 times. Download 119 times.
Department Mechanical and Electro-Mechanical Engineering
Year 2011
Semester 2
Degree Master
Type of Document
Language zh-TW.Big5 Chinese
Title Pore Formation in High Intensity Beam Drilling
Date of Defense 2012-07-20
Page Count 55
Keyword
  • Supersonic
  • two-phase flow
  • High intensity beam
  • Pore formation
  • Keyhole welding
  • Drilling
  • Abstract This text pursues the causes and phenomena in the course of the collapse of the molten metal layer surrounding a keyhole which is full of vapor and liquid particles during the high energy laser or electron beam drilling process. And the formation mechanism of the pores for the drilling process, to study the collapse phenomenon of the liquid layer is essential.
    In the research the collapse of the keyhole is taken as approximated to a transition between the slug and annular two-phase flows in a vertical pipe of varying cross-section. We develop and solve a quasi-steady, one-dimensional model for two phase flow with the assumption that the mixture in the core homogenous, ignoring the friction of the liquid layer, regarding the flow in the keyhole as supersonic, considering the mass transfer of the liquid layer to the keyhole. Two-phase flow can be liquid particle entrainment characteristics, infiltration precipitation, divided into two regions. The collapse of keyhole resulted from the infiltration of the liquid particles is chained to the pore formation. Based on the realization of annular two phase flow, In this text, that the liquid into the holes in the physical properties and caused pores formation.
    Advisory Committee
  • Han-Taw Chen - chair
  • Jeng-Rong Ho - co-chair
  • Jiin-Yuh Jang - co-chair
  • Fei-Bin Hsiao - co-chair
  • Peng-Sheng Wei - advisor
  • Files
  • etd-0803112-062732.pdf
  • Indicate in-campus at 5 year and off-campus access at 5 year.
    Date of Submission 2012-08-03

    [Back to Results | New Search]


    Browse | Search All Available ETDs

    If you have more questions or technical problems, please contact eThesys