水的粘度计算表水的动力粘度计算公式ea

温度T ℃ K 粘度μ Pa·s或N·s·m-2 ×10-3 ×10-3 ×10-3 ×10-3 ×10-3 ×10-3 ×10-3 ×10-3 ×10-3 ×10-3 ×10-3 ×10-3 ×10-3 温度 T ℃ K 粘度μ Pa·s或 N·s·m-2 ×10-3 ×10-3 ×10-3 ×10-3 ×10-3 ×10-3 ×10-3 ×10-3 ×10-3 ×10-3 ×10-3 ×10-3 ×10-3 0 1 2 3 4 5 6 7 8 9 10 11 12 21 22 23 24 25 26 27 28 29 30 31 32 13 14 15 16 17 18 19 20

×10-3 ×10-3 ×10-3 ×10-3 ×10-3 ×10-3 ×10-3 ×10-3 33 34 35 36 37 38 39 40 ×10-3 ×10-3 ×10-3 ×10-3 ×10-3 ×10-3 ×10-3 ×10-3 水的物理性质

温度t/℃ 饱和蒸气压 p/kPa 密度ρ/kg·m-3 焓 比定压热容导热系数λ/10-2W·m-1·K-1 粘度μ/10-5Pa·s 体积膨胀系数α/10-4K-1 外表张力σ/10-3N·m-1 普兰德数Pr H/kJ·kg-1 cp/kJ·kg-1·K-1 0 10 20 0 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 250 260 270 280 290 300 310 320 330 340 350 360 109 370 264 F3 Viscosity decreases with pressure

(at temperatures below 33°C)

Viscous flow occurs by molecules moving through the voids that exist between them. As the pressure increases, the volume decreases and the volume of these voids reduces, so normally increasing pressure increases the viscosity.

Water's pressure-viscosity behavior [534] can be explained by the increased pressure (up to about 150 MPa) causing deformation, so reducing the strength of the hydrogen-bonded network, which is also partially responsible for the viscosity. This reduction in cohesivity more than compensates for the reduced void volume. It is thus a direct consequence of the balance between hydrogen bonding effects and the van der Waals dispersion forces [558] in water; hydrogen bonding prevailing at lower temperatures and pressures. At higher pressures (and densities), the balance

between hydrogen bonding effects and the van der Waals dispersion forces is tipped in favor of the dispersion forces and the remaining hydrogen bonds are stronger due to the closer proximity of the contributing oxygen atoms [655]. Viscosity, then, increases with pressure. The dashed line (opposite) indicates the viscosity minima.

The variation of viscosity with pressure and temperature has been used as evidence that the viscosity is determined more by the extent of hydrogen bonding rather than hydrogen bonding strength.

Self-diffusion is also affected by pressure where (at low temperatures) both the translational and rotational motion of water anomalously increase as the pressure increases.