Lesson 6 - Principles of Fluid Mechanics 3
This lesson considers the factors which contribute to pressure loss when fluid follows through a pipe or duct system. It will examine in detail, the factors which contribute to frictional pressure losses and also losses due to the presence of fittings in the pipeline.
Frictional Pressure Losses
Frictional pressure losses in a pipe or duct are modelled using the Darcy-Weisbach equation. Its name may cause some confusion as it is often more simply called Darcy’s equation or law. There is also another equation, also known as Darcy’s law, which deals with pressure drop through porous beds. This is why we will be using the term Darcy-Weisbach throughout this unit. The development of the Darcy-Weisbach equation has a rich and confusing history, which we do not need to consider further.
Parameters which influence pressure drop
There are a number of fluid property, geometry, and fluid flow parameters which influence the pressure loss in a pipe or duct containing a flowing fluid. By now, you are developing a feel for what some of these parameters might be. Let us find out.
Consider this situation: a horizontal pipe of uniform circular cross-section carries wort. Which parameters do you think would directly influence the pressure drop (measured in N/m²) due to pipe wall friction? This task is quite difficult, so do not panic if you find it challenging. Try your best and see what you come up with.
Give yourself 5-10 mins to think about this and then click ‘Next’ to continue with this lesson.