Find the dynamic viscosity of H2 at 400 degrees and 20 atm?
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It is known that the dynamic viscosity of H2 at 20 degrees and 1 atm is 0.10969 Pa·s. Can the dynamic viscosity of H2 at 400 degrees and 20 atm be determined? Who would, let’s do the calculation.
0.000015676 Pa.s
This post was last edited by A Chao syc62100 on 2020-4-22 at 11:29. It seems that the data you provided regarding the dynamic viscosity of hydrogen at 20°C and 1 atm is also incorrect
This post was last edited by 2005011lcj on 2020-4-22 at 22:18. At 1 atm and 20 degrees Celsius, the dynamic viscosity is 1.05033 cm2/s; at 20 atm and 400 degrees Celsius, it is 0.216 cm2/s. It’s not possible to calculate the viscosity at 400 degrees Celsius just by knowing the viscosity at 20 degrees Celsius – your thinking is too simplistic. Note that kinematic viscosity and dynamic viscosity are different. Kinematic viscosity is the ratio of dynamic viscosity to the density of the fluid at the same temperature.
Upstairs, right? At 1 atm and 20 degrees Celsius, the dynamic viscosity is 1.05033 cm2/s; at 20 atm and 400 degrees Celsius, the dynamic viscosity is 0.216 cm2/s? Should the kinematic viscosity of a gas increase as both temperature and pressure rise? Why is it smaller at 400 degrees than at 20 degrees?
If you say I’m wrong, please prove first that you’re right.
Their calculations are correct. First, may I ask you: the higher the value of dynamic viscosity, the more difficult it is for the fluid to flow, right?
Yes, but what I know is that \"the higher the temperature of a liquid, the greater the pressure, and consequently the greater its dynamic viscosity as well.\" In other words, \"the higher the temperature and the greater the pressure, the more difficult it is for the liquid to flow, and the greater the resistance becomes.\" ”So, at 20 atm and 400 degrees, shouldn’t the dynamic viscosity of H2 be greater than 1.05033 cm2/s? Do you think I’m right? :handshake
For gases, the higher the temperature, the greater the pressure; the more active the gas molecules are, the easier it is for them to flow, and thus the lower the value of its dynamic viscosity. For liquids, such as oils, the higher the temperature, the more active the molecules are, the easier it is for them to flow, and consequently the lower the value of their dynamic viscosity. Additionally, liquids themselves are incompressible and can only transmit pressure