Define Objects Panel for USS

Define Objects

USS_U²NCLE allows the definition of boundary conditions, volume definitions, and an object-oriented hierarchy of components within the domain in the Define Objects panel. Initially, a surface grid is displayed in the drawing area; this provides an intuitive means by which to map boundary condition definitions to distinct surfaces in the mesh.

Several types of objects can be defined using the Define Objects Panel. They are:

Boundary Conditions (Surface Definitions)
Volume Definitions
Component Definitions
Body Definitions
User Forces

For convenience, the Define Objects panel is organized into tabs. The tabs allow for grouping of related objects into one sub-panel.

BC/Vols Tab

Purpose: Edit surface & volume boundary conditions and toggle visibility of surfaces
Edit Level: Mandatory

Surfaces and volumes can be selected by clicking on the appropriate entry in the list of available objects. As a visual cue, the selected surface is displayed in red in the drawing area. Alternately, a surface can be picked directly in the drawing area by clicking on it with the middle mouse button.

Visibility of a surface can be toggled by right clicking on the entries in the list of available objects and deselecting the Visible tag.

Double clicking on an entry in the list of available objects brings up an interactive panel that allows the user to specify names and appropriate conditions. The same effect may be achieved by right clicking on the entry in the list of available objects and selecting the Edit BCs or the Edit Volume tag as the case may be.

Bodies/Comps Tab

Purpose: Create an object-oriented hierarchy of components and bodies using the surfaces and volumes that have been previously defined
Edit Level: Optional

Components are logical groupings of surfaces and volumes, while bodies are groupings of components. This tab provides a mechanism for creating this hierarchy interactively. Choosing this tab disables picking in the drawing area.

Components can be added or deleted using the Add and Delete buttons. Once a component is created, surfaces and volumes may be added by using a drag-n-drop approach. A surface or volume that has been added in error to a particular component can be removed by right clicking on the offending party and choosing Remove.

If no components exist when this tab is selected, a default component containing all viscous and transparent sliding surfaces will be created.

Bodies are the top level objects in the present hierarchy. Bodies are exclusively made up of components. Once a body has been created, components may be added by using a drag-n-drop approach. When a component is added to a body, it is removed from the list of components (components cannot be shared between bodies). Errors in the addition process can be corrected by right clicking the offending component and selecting Remove. If a body is deleted, all of its components reappear in the list of components.

Object Definition File

Object definitions defined via the graphical interface are written to an object definition file (CaseName.bc) readable by the flow solver. Since this file maybe hand edited if desired (advanced users only), some words are appropriate concerning the format of the file. Comments may be placed freely throughout the file; any text following the '#' character will be ignored. Each object definition has the same form:

objecttype n [<name=>myname]: object_specification ;

where objecttype is the type of object being defined (such as a surface, volume, component, body, etc.), n is the ID number for that object, and object_specification describes that object. The optional "name=" field names the object with a user-selected name (the name must be alphanumeric with no embedded spaces). Note that each statement is terminated by a semicolon, and can be split across multiple lines. Whitespace is ignored appropriately. If an object is not named explicitly, it receives the objecttype and object ID as the default name. For example, the default name for surface 1 is "Surface_1".

For further information related to the materials in this web site, USS_U²NCLE, U²NCLE, SolidMesh, DIVA or information related to their use, please contact:

David L. Marcum
marcum@erc.msstate.edu

Phone: (662) 325-3193, FAX: (662) 325-7692

Computational Simulation and Design Center
Engineering Research Center for Computational Field Simulation
Mississippi State University
Box 9627, Mississippi State, MS 39762

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