Question

I am doing an experiment on fluidization. The fluid used for the experiment is gas (air). I need to know the viscosity to do some calculations. However, when I search the internet, it seems that I have found different values. May I know what is the common value use for the air at room temperature viscosity?

Answer 1

When we talk about room temperature, It leads to two possibilities: climate control for human comfort and science & industries.

For human comfort, it varies from 15⁰C to 25^oC. In science calculations and industries, it does not have a definite value for room temperature actually. Consequently, Room temperature varies from 20^oC to 25^oC. But 20^oC or 300 K is used widely for mathematical convenience. Sometimes, 25^oC is also used in many engineering books.

Now, the values of dynamic viscosity of air at 20^oC and 25^oC are $18.25 \mu Pa.s$ and $18.5 \mu Pa.s$ respectively.