(Editor’s Note: This story originally ran in November 2008 and has proved a perennial favorite of Power Engineering readers. With the New Year we thought we’d share it again. Click here to see the ...

The word “thermodynamics” conjures up visions of complex mathematics to many people, even some with technical backgrounds. Yet, relatively simple formulas from thermodynamics can be used explain much ...

When a fluid is in motion, it must move in such a way that mass is conserved. To see how mass conservation places restrictions on the velocity field, consider the steady flow of fluid through a duct ...

A streamline is a line that is tangential to the instantaneous velocity direction (velocity is a vector, and it has a magnitude and a direction). To visualize this in a flow, we could imagine the ...