Monday, 12 November 2018

fluid dynamics - What is the microscopic picture for warm air rising?


The usual explanation for warm fluids rising past cooler ones is that the warmer fluid has a lower density. I'm trying to understand what this looks like at a molecular scale. The density seems to be a large-scale phenomenon, and I don't understand how it can affect whether a particular molecule rises or falls.



Consider a cylinder of fluid that is being heated at the bottom. The molecules at the bottom have a higher average energy. How does this result in the tendency of the warmer molecules at the bottom to move upwards past the cooler ones?




No comments:

Post a Comment

Understanding Stagnation point in pitot fluid

What is stagnation point in fluid mechanics. At the open end of the pitot tube the velocity of the fluid becomes zero.But that should result...