# Fluids

FluidFlow contains a comprehensive database of over 1,280 fluids enabling you to quickly model fluid transportation systems. You can also add new fluids to the software database and also create fluid mixtures. The section below describes how you can add new fluids and create new fluid mixtures. Fluids Database: The physical properties for water are predefined in the fluids database to IAPWS (International Association for the Properties of Water and Steam) standards. Users can choose from five options when adding a new fluid to the Database: 1) Simple Newtonian, 2) Pure Newtonian, 3) non Newtonian Liquid, 4) Gas (No Phase Change) & 5) Petroleum Fraction or Crude. 1) Simple Newtonian: This option is useful when we have limited fluid physical property data available. When adding a new Simple Newtonian Fluid to the database, we only need to define the physical properties as outlined in Figure 1. When adding a new fluid to the database,we need to ensure the "Light Bulb" icon on the bottom left corner of the Fluid Editor dialog is illuminated (See Figure 1 below). This light bulb will only become illuminated when all the key fluid physical properties have been fully defined. For instance, if we don't have the physical property data for the Liquid Specific Heat or Liquid Thermal Conductivity and we leave these parameters undefined, although the fluid might appear in the database on the left hand side, the "Light Bulb" icon will remain off. This means that the fluid is only partially defined and if you try to select this fluid for a boundary node from the input tab, it will not be available. The Liquid Specific Heat and Liquid Thermal Conductivity are only required if we are performing heat transfer analysis. If you are not completing a heat transfer calculation as part of your model, you can accept the default values (that of water) offered by FluidFlow. When all fluid physical properties are fully defined, the "Light Bulb" icon will illuminate automatically meaning the fluid is now available to model in a system. Note, a Simple Newtonian fluid is only suitable for liquid phase flows with no phase change. As only the liquid physical properties are defined, only the Liquid "Light Bulb" icon appears illuminated. Figure 1: Data Entry for Simple Newtonian Fluid. 2) Pure Newtonian: FluidFlow is provided with an extensive database of Pure Newtonian fluids as standard. Figure 2 provides details of the physical property data required when defining a fluid as Pure Newtonian. If you wish to model a piping system in which the fluid may experience changes in phase state, it is recommended the system is assigned with a Pure Newtonian fluid. FluidFlow will then automatically determine the fluid phase state throughout the system based on the operating pressures, temperatures and engineering conditions which apply. Note, in Figure 2 the "Light Bulb" icon is illuminated for Liquid, Gas & 2 Phase as the physical properties for this sample fluid (diethyl disulfide) are fully defined. This therefore denotes that this particular fluid can be modeled as liquid, gas or two phase. Figure 2: Data Entry for Pure Newtonian Fluid. 3) non Newtonian Liquid: To accurately predict friction loss and system operating conditions for non-Newtonian fluid flow in pipelines, good laboratory data is required. The fluid data-entry requirements are shown in Figure 3. Figure 3: Data Entry for non-Newtonian Fluid. Thermodynamic Properties: In designing slurry pipelines, it is more often the case that a heat transfer calculation is not required, and hence thermodynamic properties are rarely available. However, FluidFlow will only allow access to a fluid in the database when it is fully defined – i.e., these physical property fields cannot be left undefined even though the values are not used for calculation purposes. If the heat transfer calculation is not required, then it is recommended that the default values are accepted. If the intention is to perform heat transfer calculations then this data must be entered correctly. Vapor Pressure: Again it's unlikely that specific data will be available and so, FluidFlow Slurry provides the option of simply selecting the pre-set values for water. Remember, vapor pressure does not contribute to friction loss and is only important where system pressure falls below vapor pressure. Liquid Viscosity Definition: The FluidFlow Slurry Module allows you to enter the relationship of a fluid's shear-dependent viscosity according to four rheology (curve-fit) models. These include: Power Law, Hershel Bulkley, Casson & Bingham Plastic. Engineering judgment must be applied to select the appropriate rheology curve-fit model based on the available data. Once you have defined the shear stress-shear strain curve coordinates, you can click-through each of the four curve fit options, taking care to select the most suitable relationship. 4) Gas (No Phase Change): Users can also add new fluids to the database where the phase state is fixed to gas. An example of such a fluid from the database is Steam (Figure 4). Figure 4: Data Entry for Gas (No Phase Change). 5) Petroleum Fraction or Crude: Users can add pseudo-component fluids to the database and model in piping systems. When adding a new pseudo-component fluid, simply define the True Boiling Point (TBP) or ASTM curve along with the fluid density and FluidFlow will automatically determine all fluid physical properties (refer to the fluid physical properties contained within the red box in Figure 5). Note, when entering the fluid data, the density of the fluid should be entered at a temperature of 288.65 K. Figure 5: Data Entry for Petroleum Fraction or Crude. Note, if you have the fluid True Boiling Point curve data, this can be entered into the database in which case, FluidFlow will automatically generate the ASTM D86 curve plot. If you define the ASTM D86 curve in the database, the software will automatically generate the True Boiling Point curve. The correlation used in FluidFlow for interconversion between ASTM D86 and True Boiling Point is: TBP = a(ASTM D86)b where a and b are constants varying with the percent of liquid distilled. Figure 6 provides an illustration of the two curves (ASTM D86 & TBP) as developed by FluidFlow. Figure 6: ASTM D86 & True Boiling Point Curve for Gas Oil (Heavy Distillate). In determining the fluid physical properties, FluidFlow also determines the Volume Average Boiling Point (VABP), Watson K factor and MeABP. The correlations used to estimate these properties are as follows: VABP = T10 + T30 + T50 + T70 + T90 / 5. where all temperatures are in oF. Watson K factor = (MeABP)1/3 / SG. where MeABP = VABP - Δ. where Δ is determined from the equation: ln Δ = -0.94402 - 0.00865(VABP - 32)0.6667 + 2.99791 SL0.333. where SL = T90 - T10 / 90 - 10. Using the above correlations, FluidFlow automatically determines all fluid physical properties required in order to successfully model the feedstock in the network. The production copy of the fluids database includes a number of pseudo-component fluids such as: gasoline, gas oil, kerosene, diesel oil, etc. Fluid Mixtures. Fluid mixtures may also be created in FluidFlow by choosing from two methods: 1) Database Mixtures and 2) Flowsheet Mixtures. Database Mixtures New fluid mixtures can be created using fluids already defined in the software database. Gas Mixtures can be defined by weight % or by mole % (volume %). To create a new mixture select: Database | Fluids | New Mix and then choose from the fluids available in the Fluid Editor dialog. Note, care should be taken to ensure the Percent Sum of the mixture is exactly 100 % otherwise you will not be able to model the fluid in a system. Flowsheet Mixtures Fluid mixtures can also be created dynamically on the flowsheet by adding new fluids to a network using either a Known Flow or Known Pressure node. Figure 7 shows how methanol, ethanol, butanol and nonanol are mixed dynamically on the flowsheet and the software automatically calculates the composition mass % for each component in the system. Figure 7: Creating fluid mixtures dynamically on the flowsheet. The section below describes the options available on the "Fluid Editor" form as shown in Figure 1. View: Users can customize the display of the fluid list. There are two options to choose from: 1) Show Chemical Names and 2) Show Alternative Names. When we select "Show Chemical Names", the fluids are displayed based on the data stored in the "Formula" field (Figure 1). When we select "Show Alternative Names", the fluids are displayed based on the data stored in the "Alternative Names" field. Filter: Users can filter the fluid types displayed in the Fluid Editor by choosing any of the five available options: 1) Pure Newtonian, 2) Simple Newtonian, 3) Non Newtonian, 4) Gas (No Phase Change) or 5) Petroleum Fraction or Crude. Setting the filter to "Pure Newtonian" means only Pure Newtonian fluid types will be shown. Setting the filter to "Simple Newtonian" means only Simple Newtonian fluid types will be shown. This approach can be applied to any of the five fluid types. Search: This allows you to search the fluid list for a particular fluid name. New Mix: This button allows you to create a new fluid mixture using the fluids which already exist in the database. Note, if you are creating a new mixture and one of the component fluids doesn't already exist in the fluids database, you can add this new component fluid to the database and then assign to your new mixture. The approach required to add a new fluid mixture to the database is described in further detail above. Add: This button allows you to add a new fluid to the database. The approach required to add a new fluid to the database is described in further detail above. Delete: This button allows you to delete a fluid record from the database. Load: You can load a ".fluid" file to the "DATA" Folder stored on your local PC or network if another user has saved (see step described below) and shared their fluid data with you. Save: This option allows you to save a fluid ("clone") as a ".fluid" file type. This means if you have created a new fluid in your local database (stored on your "DATA" Folder), you can save the fluid file and share with another user. The user can then save the .fluid file to their local PC, select the "Load" button which will load-in the new fluid file data to their local database.