Does Pipe Flow Expert allow different fluids within a single pipe network?
Yes. The Pipe Flow Expert software will allow you to create systems with up to 20 different fluid zones, where each zone has a fluid with a different fluid density and fluid viscosity.
Use of fluid zones allows the user to model different parts of the piping system using fluid characteristics that match the conditions within each section. This allows the user to model systems that contain more than one fluid, perhaps where two different fluids flow through a mixer and emerge as a third fluid with different density and viscosity properties.
Fluid zones also allow the user to take account of any major changes in fluid density and viscosity due to temperature changes, perhaps as a fluid passes through a boiler or pass through some other component that changes its temperature.
Note: The software does not calculate thermal properties and the effect of temperature change is not automatically modeled, therefore any significant changes to the fluid properties due to temperature change should be accounted for by defining a new fluid zone at the appropriate point within the system.
Compressible Flow (Gas Flow)
For gas systems that are solved using the Compressible Gas Flow Calculation Engine, the software automatically takes account of changes in fluid density due to compression or expansion of the fluid that occurs as pressure changes within the network.
For systems where temperature changes affect the fluid properties, it is up to the user to define fluid zones that reflect any changes in fluid density and viscosity within the model.
While the software allows for up to 20 different fluid zones within a single model, the model must be an either an all liquid or an all gas system. The software does not currently calculate for two phase flow where a system essentially has a fluid that is changing state between liquid and gas phases.