Offset Node ID’s by. By choosing this option, the nodes representing the insulation will
have ID numbers offset from the underlying surface node ID by the specified amount. For example, if a surface with node MAIN.1 has insulation with Number of Nodes set to 3 and Offset Node ID’s by equal to 1000, the insulation will be represented by nodes MAIN.1001, MAIN.2001, and MAIN.3001, from the surface, outward.
Important: If the Number of Nodes on top and bottom of a surface are both greater than one, the user should choose the Node ID Offset carefully to prevent duplication of IDs.
Use new submodel. By choosing this option, the nodes representing the insulation will use
the same ID number as the underlying surface, but will be placed in the specified submodel. This option limits the Number of Nodes to one. This option cannot be used with Recession (Section 3.2.7).
Figure 4-14 Insulation Nodalization Insulation Node
Not in graphics, but created for SINDA SINDA.ID
from Node Numbering Page
Submodel.ID from Insulation Page
Conductor across the two is determined by the material defined on the insulation page. This can be a radiation conductor for MLI, a linear conductor, or both.
Calc Type. The Calc Type drop-down gives the options: Based on material property and Arithmetic. By choosing arithmetic, the insulation nodes will be assumed massless (this option is not recommended for Recession, Section 3.2.7). By choosing Based on material property, the insulation nodes will be generated as diffusion nodes, if possible.
Init temp. This field allows specifying the initial temperature of the insulation nodes for
transient solutions.
Overrides. The override button at the bottom of each insulation set allows the user to specify
which nodes have insulation. If no overrides are input, then the insulation is placed on the entire surface. The override list consists of a single column of node numbers in submodel.ID format.
Note: If overriding surface insulation, be sure to include overrides on the Radiation tab, also, if the surface optical properties will be different.
4.3.1.7 Surface Tab
If a custom conic surface is being edited, surface parameters may be edited directly using the Thin Shell Data dialog box Surface tab (Figure 4-15). Labels for the input fields are adjusted according to the type of surface being edited and checking for validity of the parameters will be done when OK is selected or a different tab selected. Surface parameters may also be modified using interactive grips.
The Comment field is a multi-line field that is extremely useful for model documenta- tion. See "Comment Field" on page 2-41 for more information. The first line of the comment field provides object identification in three locations: the Model Browser (see "Model Browser" on page 2-8), the tool tip that appears when the cursor is positioned over the object, and as a comment line in the SINDA/FLUINT conductance/capacitance file.
4.3.1.8 Trans/Rot Tab
The user may specify additional translations and rotations for the surface using the TRANS/ROT tab. The tab is shown in Figure 4-16. These rotations and translations are
relative to the initial origin and local coordinate system of the surface. The user has the option to specify the order of the rotations by using the drop-down menus for each axis.
4.3.2 Box
A box is a group of five or six surfaces created together using the Thermal > Surfaces/ Solids > Box menu choice. Initially, the Create Box form (Figure 4-17) opens and the user selects the nodalization and the number of sides for the box (Note that a 5-sided box will not have a ZMIN face). The actual object(s) created will depend on the nodalization selected. 2x2 Edge Nodes will generate five or six individual rectangles with Subdivisions set to two, edge nodes selected and the nodes merged. Either 1 Node per Face or 1 Node for the box will generate a single mesh: the subdivisions cannot be changed and the sides cannot be individually edited. Selecting the mesh will provide grip points at each vertex that can be individually moved. The 1 Node per Face option will generate conductors between faces
when a SINDA/FLUINT file is created; the 1 Node for the box option only has one node and therefore has only one temperature and no conductors; the 2x2 Edge Nodes option has merged nodes at the vertices so no conductors are necessary.
After selecting the nodalization, the user is queried for the origin, the point for the +X axis and the X-size, the point to set the XY plane and the Y-size, and the point to set the Z- size or a length for the Z-size.
When the dimensions have been specified, the edit form appropriate for the nodalization will be opened.
4.3.3 Cone
A cone is created using the Thermal > Surfaces/Solids > Cone menu choice. The following prompts will appear at the command line:
>: Pick or enter point for base of cone <0,0,0>: Click a point on the screen for the base of cone
This point defines the base and partially defines the centerline.
>: Pick or enter point for top of cone <@0,0,1>: Click a point on the screen for the top of cone
The vector from the base point to the top of the cone defines the centerline and the +Z axis. The local +X axis is computed so as to lie in the current User Coordinate System (UCS) XY plane, and the +Y axis follows from the right-hand rule. The UCS is repositioned at the base point with the axes aligned with surface’s local coordinate system for the remainder of the inputs. Points entered at the command line prompt may be proceeded with an asterisk (*) to use the World Coordinate System, rather than the local coordinate system. The UCS is reset to the previous UCS after the surface has been created.
>: Enter base radius or pick/enter point <0.0>: Enter a value or point, or pick a point on the screen
The base radius may be entered directly or computed from a point entry. A return without entering a value creates a cone with a base radius of zero. The base radius may be less than, equal to, or greater than the top radius.
>: Enter top radius or pick/enter point <1.0>: Enter a value or point, or pick a point on the screen
The top radius may be entered directly or computed from a point entry. A return without entering a value creates a cone with a top radius of one. The top radius may be less than, equal to, or greater than the base radius (only one of the radii may be zero, however).
>: Enter start angle or pick/enter point <0.0>: Enter a value or point, or pick a point on the screen
The starting angle for the cone is referenced counterclockwise from the local +X axis. A return without entering a value starts the cone at the local +X axis.
If a point is input, the line connecting the origin to the point is projected into the local XY plane to determine the angle from the local X axis.
>: Enter end angle or pick/enter point <360.0>: Enter a value or point, or pick a point on the screen
The end angle for the cone is referenced counterclockwise from the local +X axis. A return without entering a value ends the cone at the local +X axis.
If a point is input, the line connecting the origin to the point is projected into the local XY plane to determine the angle from the local X axis. The Thin Shell Data dialog box (Figure 4-7) will appear after this prompt to allow specification of thin shell data.
The grip points for the cone are shown in Figure 4-18. The move origin grip point moves the origin of the cone to the newly selected point. The cone is translated with the origin.
The stretch top grip point stretches the cone along its centerline. The new height of the cone is set by projecting the line from the grip point to the picked (or entered) point along the centerline of the cone.
The grip point three quarters of the way from the base to the top of the cone is the aim
Z axis grip point. Selecting this grip and then entering or picking a point will orient the cone
so that the +Z axis is aimed at the point by rotating about the base point in the plane formed by the current +Z axis and the vector from the base point to the pick point. The height is left unchanged.
The set start angle and set end angle grip points are located at one quarter and three quarters of the height at the start and end edges of the cone. An angle is set by projecting the line from the origin to the picked point onto the local XY plane.
The set base radius grip is located on the base of the cone, half way between the start and end angles. Selecting the base radius grip and picking a point will modify the cone’s base radius by projecting the line from the base point to the picked point onto the local XY plane. The distance of the projected line is used for the radius.
The set top radius grip is located on the top of the cone, half way between the start and end angles. Selecting the top radius grip and picking a point will modify the cone’s top radius by projecting the line from the base point to the picked point onto the local XY plane. The distance of the projected line is used for the radius.
The top radius may be less than, equal to, or greater than the base radius, except that both cannot be zero. The orientation of the nodal breakdown is always counterclockwise from the start edge, then proceeding from the base to the top.
If the top or base radius is zero, the radius grip and the stretch grips will coincide. In this case, the grip will always modify the radius. To modify the height of a cone that has a zero radius top or base, drag the grip slightly to set a non-zero radius, modify the height, and then set the radius back to zero. The cursor will automatically snap to displayed grips, making the input operation easy.
4.3.4 Cylinder
A cylinder is created using the Thermal > Surfaces/Solids > Cylinder menu choice. The following prompts will appear at the command line:
>: Pick or enter point for base of cylinder <0,0,0>: Enter or pick a point on the screen
This point defines the base and partially defines the centerline.
>: Pick or enter point for top of cylinder <0,0,0>: Enter or pick a point on the screen
Figure 4-18 Thermal Desktop Cone Grip Points
Set Top Radius
Stretch Top
Aim Z Axis Set End Angle
Set Base Radius
Move Origin
Set Start Angle Set Top Radius
Stretch Top
Aim Z Axis Set End Angle
Set Base Radius
Move Origin
The vector from the origin point to the top of the cylinder defines the centerline and the +Z axis. The local +X axis is computed so as to lie in the current UCS XY plane, and the +Y axis follows from the right-hand rule. The local +X axis is com- puted so as to lie in the current User Coordinate System (UCS) XY plane, and the +Y axis follows from the right-hand rule. The UCS is repositioned at the base point with the axes aligned with surface’s local coordinate system for the remain- der of the inputs. Points entered at the command line prompt may be proceeded with an asterisk to use the World Coordinate System, rather than the local coordi- nate system. The UCS is reset to the previous UCS after the surface has been cre- ated.
>: Enter radius or pick/enter point <1.0>: Enter a value or point, or pick a point on the screen
The radius may be entered directly or computed from a point entry. A return with- out entering a value creates a cylinder with a radius of one.
>: Enter start angle or pick/enter point <0.0>: Enter a value or point, or pick a point on the screen
The starting angle for the cylinder is referenced counterclockwise from the local +X axis. A return without entering a value starts the cylinder at the local +X axis. If a point is input, the line connecting the origin to the point is projected into the local XY plane to determine the angle from the local X axis.
>: Enter end angle or pick/enter point <360.0>: Enter a value or point, or pick a point on the screen
The end angle for the cylinder is referenced counterclockwise from the local +X axis. A return without entering a value ends the cylinder at the local +X axis. If a point is input, the line connecting the origin to the point is projected into the local XY plane to determine the angle from the local X axis. The Thin Shell Data dialog box (Figure 4-7) will appear after this prompt.
The grip points for the cylinder are shown in Figure 4-19. The move origin grip point moves the origin of the cylinder to the newly selected point. The cylinder is translated with the origin.
The stretch top grip point stretches the cylinder along its centerline. The new height of the cylinder is set by projecting the line from the grip point to the picked (or entered) point along the centerline of the cylinder.
The grip point three quarters of the way from the origin to the top of the cylinder along the centerline is the aim Z axis grip point. Selecting this grip and then entering or picking a point will orient the cylinder so that the +Z axis is aimed at the point by rotating about the base point in the plane formed by the current +Z axis and the vector from the base point to the pick point. The height is left unchanged.
The start angle grip is located along the starting edge, and up one quarter of the height along the Z axis. The end angle grip is located at the ending edge, up three quarters of the height along the Z axis. An angle is set by projecting the line from the origin to the picked point onto the local XY plane.
The radius grip is located on the base of the cylinder, half way between the start and end angles of the cylinder. Selecting the radius grip and picking a point will modify the cylinder’s radius by projecting the line from the origin to the picked point onto the local XY plane. The distance of the projected line is used for the radius.
Want "Hands-On" Information? Gain experience working with cylin-
ders by completing Section 21.6 "Orbital Maneuvers" on page 21-87.
4.3.5 Disk
A disk is created using the Thermal > Surfaces/Solids > Disk menu choice. The following prompts will appear at the command line:
>: Pick or enter point for center of disk <0,0,0>t: Enter or pick a point on the screen
This point defines the center of the disk.
>: Pick or enter point for +Z axis of disk <@0,0,1>: Enter or pick a point on the screen
The vector from the origin point to this point defines the +Z axis. The local +X axis is computed so as to lie in the current UCS XY plane, and the +Y axis follows
Figure 4-19 Thermal Desktop Cylinder Grip Points
Stretch Top Aim Z Axis Set End Angle
Set Radius
Move Origin