Fluid Library

AFT Fathom provides an AFT Standard fluid library for numerous common fluids. If the working fluid you wish to model is not in this library, you may elect to enter the fluid properties in a custom library for later reuse using the Edit Fluids panel in the Library Manager.

You can open the Edit Fluids panel from the Library menu or from the Edit Fluid list button in the Fluid panel in Analysis Setup. The Edit Fluids panel allows you to review currently defined AFT Standard and custom fluids, to change the data for custom fluids, and to enter new fluids. All AFT Standard fluid properties are assumed to be a function of temperature. Custom fluids can be a function of temperature or solids concentration.

Once you have entered a custom fluid, it will appear in the Fluids Available in Library list of the Fluid panel when User Library Fluid is selected.

Adding a Custom Fluid

You can add new fluids by clicking the Add New Fluid button on the Edit Fluids panel of the Library Manager. Raw data can be provided for the variation of density, dynamic viscosity, specific heat, thermal conductivity, and vapor pressure as they depend on temperature or solids concentration. This window provides the tools to perform polynomial curve fits of fluid data, or the raw data can be interpolated.

Required Data:

• Density

• Dynamic Viscosity

Optional Data:

• Specific Heat (required for heat transfer capabilities)

• Thermal Conductivity (required for heat transfer capabilities)

• Reference Temperature/Enthalpy point (required for heat transfer capabilities) - Note that the reference temperature/enthalpy do not need to be exact values since only changes in the parameters are used

• Vapor Pressure (required if checks and warnings for cavitation are desired)

The Fluid Library window also allows you to open the Change Fluid Data window which is essentially the same window as the Add New Fluid window. For easy editing, data for the fluid you wish to change is entered for you in the appropriate areas. The original curve fit data you entered is also displayed.

The Add New Fluid/Change Fluid Data windows offer cross-plotting of your custom curves against the curve fit data points. You can also import data from text files into these windows.