Main Question or Discussion Point
Hello... I can't find the difference between the pressure drop in a pipe due to frictionnal loss and the Pressure difference that cause the flow like in Poiseuille Flow.. Thanks
In polymer processing applications, typically involving high viscosity polymer melts (say 1000 Poise), the Poiseuille pressure drop equation is used extensively. This includes the entire man-made fiber industry, polymer granule production industry, and plastics manufacture industry. In addition, it applies to flow of ordinary fluids through capillaries.If you are asking how this solution to pressure drop is associated with similar ideas such as the Darcy-Weisbach equation, the answer is that the analytical (experimentally derived) Darcy-Weisbach equation is employable under broader circumstances.
In theory this is a nice equation to look at to understand where the mechanical energy is being lost to, but in practical applications of pressure drop analysis it is rarely, if ever, employed.
Basically: Poiseuille equation is theoretical, solutions like Hazen-Williams and Darcy-Weisbach are analytical.