川嶋 大介

© Institution of Mechanical Engineers 2015. This paper presents experimental results on the friction factor of gaseous flow in a PEEK micro-tube with arithmetic mean roughness of 0.2 μm (relative surface roughness of 0.04%). The experiments were performed for nitrogen gas flow through the micro-tube with 514.4 μm in diameter and 50 mm in length. Three pressure tap holes were drilled on the PEEK micro-tube wall at intervals of 5 mm and the local pressures were measured. The quasi-local friction factor is obtained from the measured pressure differences. The experiments were conducted in the turbulent flow region. The quasi-local friction factor obtained from the present study is compared with those in the available literature and also numerical results. The quasi-local friction factor obtained is 12-20% higher than the value predicted from the Blasius formula.

<p>本論文では，マイクロ流路チップ内において酸・アルカリ水溶液の中和反応より生成する塩濃度を可視化するため，近赤外域の単一波長を利用した新しいイメージング技術を提案する．本イメージング法は，水のν₁+ν₃吸収バンド内にある波長1520 nmの吸収特性を利用する．波長1520 nmは，酸やアルカリ水溶液特有の等吸収点であり，これらの溶質濃度の増減によって吸光度が変化しない．一方，塩濃度に関しては吸収感度があるため，この波長の吸光度測定により塩濃度を見積もることができる．単一波長を利用した本手法を評価するため，T字型マイクロ流路を用いて，(i)水とNaClの混合および(ii) 塩酸と水酸化ナトリウム水溶液の反応拡散の2条件についてNaCl濃度の可視化実験を行った．測定したNaCl濃度は数値解析結果と比較してよく一致しており，提案手法の有効性を示した．</p>

This paper focuses on data reduction of friction factor of compressible fluid flowing through micro-channels. The both pressure and temperature are required to calculate the friction factor of compressible flow. Therefore, in the past data reduction of many experiments, the friction factors have been obtained under the assumption of isothermal flow since temperature measurement of compressible flow in micro-channels is quite difficult due to the experimental technique limitation. The authors find that the temperature of the fluid can be obtained from the pressure under the assumption of one dimensional flow in an adiabatic channel (Fanno flow). In this paper, the temperatures obtained by our proposed equation are compared with results of numerical simulations and friction factors are also compared. © 2014 Elsevier Ltd. All rights reserved.

This paper focuses on temperature rise due to the viscous dissipation in liquids flowing through micro-channels. In the past, equations for the prediction of the temperature rise have been obtained as a function of the friction factor, Reynolds number and Eckert number or a similar form, starting from Navier-Stokes equation and energy equation under the assumption of fully developed laminar flow by researchers. The temperature rises calculated from the equations have been compared with experimental data and the equations have been validated. However, in this paper, a new equation for the prediction of the temperature rise is simply obtained from the first law of thermodynamics without restriction of fully developed laminar flow. © 2012 Elsevier Ltd. All rights reserved.