Hello,

I wondered if anyone could advise me on how to decide when to use the effect of surface tension. If you have a situation where there is an air-water interface, do you use the surface tension effect?

Look foward to hearing from you.

Regards Jennifer

Jennifer,

Assuming you're dealing with free surface flows here....

If you think about the surface tension effects in a test tube where the water wets the walls forming a maniscus, there is a deviation in the surface shape on the order of millimeters. If you are simulating something like bubbles or droplets where the shape of an individual droplet is important to your results, or a channel on the order of a few cm, then the surface tensions effects may be important. If on the other hand you're dealing with say channel flow of water in a 1m wide duct or mixing tank, then the surface tension effects are probably not important.

Jeff