pure viscous flow

例句：

1. 1. The pure viscous flow of the liquid is essential for the operation of the pump.
   液体的纯粘性流动对于泵的操作至关重要。
2. 2. In the pure viscous flow, the particles are moving in a straight line without any resistance.
   在纯粘性流动中，粒子以直线运动，没有任何阻力。
3. 3. The pure viscous flow of the oil was responsible for the smooth operation of the machine.
   油的纯粘性流动是机器顺畅运行的原因。