17.6.2.23. Mass Flow Rate

Mass Flow Rate is available for 3D simulations and 2D simulations for Plane Stress and Axisymmetric behaviors only. For the required geometry settings for Plane Stress and Axisymmetric behaviors, see the 2D Analyses section of the Help.

You apply the Mass Flow Rate boundary condition on the edges of Line Bodies whose Model Type property is specified as Thermal Fluid. This loading is needed to account for heat distribution which occurred due to the mass transportation of the fluid (mass/time).

This page includes the following sections:

Analysis Types

Mass Flow Rate is available for the following analysis types:

Dimensional Types

The supported dimensional types for the Mass Flow Rate boundary condition include:

  • 3D Simulation

  • 2D Simulation

Geometry Types

The supported geometry types for the Mass Flow Rate boundary condition include:

  • Wire Body/Line Body/Beam

Topology Selection Options

The supported topology selection options for Mass Flow Rate include:

  • Edge

Magnitude Options

The supported Magnitude options for Mass Flow Rate include the following:

  • Constant

  • Tabular (Time Varying)

  • Function (Time Varying)

Applying a Mass Flow Rate Boundary Condition

To apply Mass Flow Rate:

  1. On the Environment Context tab, click Mass Flow Rate. Alternatively, right-click the Environment tree object or in the Geometry window and select Insert>Mass Flow Rate.

  2. Define the Scoping Method as either Geometry Selection or Named Selection and then specify the geometry.

  3. Enter a Magnitude value.

Note:  The positive direction for Mass Flow Rate corresponds to the direction of the scoped edge. If you are scoping multiple edges, turn on the Direction option via the Edge group to display the fluid flow direction of the edges in the Geometry window.

Details Pane Properties

The selections available in the Details pane are described below.

CategoryProperty/Options/Description
Scope

Scoping Method: Options include:

  • Geometry Selection: Default setting, indicating that the boundary condition is applied to a geometry or geometries, which are chosen using a graphical selection tool.

    • Geometry: Visible when the Scoping Method property is set to Geometry Selection. Displays the type of geometry (Edge) and the number of geometric entities (for example: 1 Edge, 2 Edges) to which the boundary has been applied using the selection tools.

  • Named Selection: Indicates that the geometry selection is defined by a Named Selection.

    • Named Selection: Visible when the Scoping Method property is set to Named Selection. This field provides a drop-down list of edge-based Named Selections that are based on the target line body or line bodies.

Definition

Type: Read-only field that displays boundary condition type - Mass Flow Rate.

Magnitude: speed of the flow.

Suppressed: Include (No - default) or exclude (Yes) the boundary condition.

Mechanical APDL References and Notes

The following Mechanical APDL commands, element types, and considerations are applicable for this boundary condition.

  • Mass Flow Rate is applied using the SFE command directly on FLUID116 elements representing Thermal Fluid line bodies.

  • Mass Flow Rate (constant, tabular, and function) is always represented as a table in the input file.