Ryoji Tsujino

Numerical Simulation of Gas-Liquid Two-Phase Flow in a Horizontally Placed Hydrophobic Rectangular Channel (Part 2, Influence of Abrupt Contraction)

Abstract This paper computationally visualizes two-phase flow patterns through a horizontally placed hydrophilic or hydrophobic rectangular channel with an abrupt contraction. The rectangular duct used in this study has a thickness narrower than the Laplace constant so that the surface tension governs the fluid system rather than the inertia force. In particular, the computed bubble behavior at the abrupt contraction seemed to be a similar nature against the preliminary experimental result.

Statistical analysis of optimum friction welding conditions for 6061 aluminium alloy friction-welded joints

Abstract Conferring lightweight and good corrosion resistance, aluminium alloy joints are extensively required in the manufacture of various types of electrical and mechanical components. Research data previously obtained by the authors1, 2 show the efficiency of friction-welded joints, regardless of whether produced from similar or dissimilar materials, to be fairly well scattered under identical sets of friction welding conditions and underline the need for statistical analysis of a large number of joints to determine the suitability of any specific set of friction welding conditions. That is to say, joints with a high mean joint efficiency that are friction-welded under optimum friction welding conditions conform to a normal distribution with low scatter during such statistical analysis while simultaneously showing a large Weibull distribution shape parameter and small dispersion. On the other hand, joints with a low mean joint efficiency that are friction-welded under unsuitable friction welding conditions conform to a positively or negatively skewed distribution with heavy scatter while simultaneously having a small Weibull distribution shape parameter and large dispersion.