Products Abaqus/Standard Typical ApplicationsSlurry fluid pipe connector and thermal-slurry fluid pipe connector elements are typically used to simulate the junction between two or more slurry fluid pipe and thermal-slurry fluid pipe elements (see Slurry Fluid Pipe Elements) such as a valve, a T-connector, or a diffuser. Choosing an Appropriate ElementSeveral connector elements with only slurry concentration and pore pressure or with slurry concentration, pore pressure, and thermal degrees of freedom are available. They can be broadly classified as follows:
The geometric layout of the regular and annular thermal-slurry fluid pipe connector elements and the corresponding element connectivities are similar to that shown for regular and annular thermal fluid pipe connector elements in Thermal Fluid Pipe Connector Elements. Assigning a Material Definition to a Set of Thermal Fluid Pipe Connector ElementsYou must associate a material definition with each connector element section property. The material that is defined for the slurry fluid pipe connector section refers to the fluid that is flowing through the connector. You must define the fluid density and the viscosity of the slurry to describe its flow behavior. The density of the slurry can be specified to be a function of the slurry concentration. In this case, the density is computed using the density of the fluid and the solid proppant particles, as well as the slurry concentration, using a rule of mixtures. The viscosity of the slurry can be specified as a function of the slurry concentration directly in tabular form. For the viscosity definition, slurry fluid pipe elements support both Newtonian and non-Newtonian fluids. The following non-Newtonian fluid models are supported: power law, Bingham Plastic, and Herschel-Bulkley models (see Viscosity). For the thermal slurry fluid pipe connector elements, you must also specify the following thermal properties:
Input File Usage Use the following options to specify the flow and thermal properties of the fluid: FLUID PIPE CONNECTOR SECTION, MATERIAL=material name MATERIAL, NAME=material name VISCOSITY, DEFINITION=NEWTONIAN or POWER LAW or HERSCHEL-BULKLEY or BINGHAM PLASTIC, SLURRY DENSITY, PORE FLUID, SLURRY CONDUCTIVITY, PORE FLUID, SLURRY SPECIFIC HEAT, PORE FLUID, SLURRY In addition, use the following options to specify the thermal properties for the pipe wall connector: DENSITY CONDUCTIVITY SPECIFIC HEAT Multiple Fluid FlowAbaqus allows the use of multiple fluids in an analysis, up to a maximum of four fluid types. This capability is useful in situations where the spatial distribution of the different fluid types is known (precomputed) at all times during the analysis. In other words, the type of fluid at each node in the domain is known at all times during the analysis. The definition of multiple fluids in an analysis involves assigning a unique integer value that acts as an identifier for each fluid type, and associating each fluid identifier with a specific predefined field variable used to specify the spatial distribution of the fluid as function of time. You can utilize the fluid identifier to specify the properties (for example, viscosity) of each fluid. The field variable associated with a fluid type allows you to predefine the fluid type at a node as a function of time using amplitude definitions or as functions of both time and space utilizing user subroutine UFIELD or USDFLD. You specify a value for each field variable, associated with a fluid identifier, at each node. It is recommended that you specify a value for the field variable ( ) such that . Abaqus assigns the fluid type at an integration point to be the one for which the field variable has the maximum value at that point. If all field variables have the same numerical value at an integration point, the first fluid (fluid identifier equal to 1) is assumed to be active. Input File Usage VISCOSITY, FLUID ID=Fluid Id number, DEFINITION=NEWTONIAN or POWER LAW or HERSCHEL-BULKLEY or BINGHAM PLASTIC, SLURRY FLUID ID FIELD Fluid Id number, field_id Slurry Fluid Pipe Connector EquationsThe main governing equations for the fluid flow and pressure loss are described in Fluid Pipe Connector Equations. For information about the different options for defining discrete pressure loss, see Specifying the Fluid Pipe Connector Geometry and Connector Loss. You can also define control valve behavior in slurry fluid pipe connector elements as described in Specifying the Control Valve Behavior. The main governing equations for the thermal behavior are described in Thermal Fluid Pipe Connector Equations. For the thermal-slurry fluid pipe connector elements, the thermal loss and connector wall diameters can be specified as shown in Specifying the Thermal Loss in the Fluid and Specifying the Wall Diameters for Thermal Fluid Pipe Connector Elements. When you specify the connector loss terms for the fluid pressure loss as described in Specifying the Fluid Pipe Connector Geometry and Connector Loss, you must ensure that these terms account for the flow of slurry (in other words, they should not define only the carrier fluid). The density that is used for computing the pressure loss is the mixture density (computed using the density of the fluid and the solid proppant particles) and the slurry concentration, using a rule of mixtures. The slurry concentration stays constant through the slurry fluid pipe connector element and thermal-slurry fluid pipe connector element. Specifying Initial and Prescribed ConditionsYou can define an initial slurry concentration, an initial temperature, and a field distribution over the nodes of the slurry fluid pipe connector element and thermal-slurry fluid pipe connector element. Input File Usage Use one or both of the following options: INITIAL CONDITIONS, TYPE=TEMPERATURE INITIAL CONDITIONS, TYPE=FIELD INITIAL CONDITIONS, TYPE=SLURRYVF Specifying Loads and Boundary ConditionsSlurry fluid pipe connector elements and thermal slurry fluid pipe connector elements allow for the specification of pressure boundary conditions and volumetric flow rates at the nodes. The flow rate must be a nonzero value. At a particular node, you can specify either a pressure or flow rate but not both. Because the slurry fluid pipe connector elements do not use the geometric length in the fluid equilibrium equations, gravity loads are not supported for these elements. You can also specify boundary conditions on the slurry concentration and temperature degree of freedom. Input File Usage Use the following option to specify the pressure at the inlet or outlet: BOUNDARY node or node set, 8, 8, magnitude Use the following option to specify the flow rate at the inlet or outlet: CFLOW node or node set, , magnitude Use the following option to specify the temperature at the inlet or outlet: BOUNDARY node or node set, 11, 11, magnitude Use the following option to specify the slurry volume fraction at the inlet or outlet: BOUNDARY node or node set, 31, 31, magnitude | |||||||||||||||