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SF
MP ME ST PR PRN <> <> FL
EM EH <> PP <> EME MFS
Nlist
Nodes defining the surface upon
which the load is to be applied. Use the label ALL or P, or a component name.
If ALL, all selected nodes [NSEL] are used (default).
If P, graphical picking is enabled and all remaining command fields are ignored
(valid only in the GUI).
Lab
Valid surface load label. Load
labels are listed under "Surface Loads" in the input table for each
element type in the Element Reference.
Discipline
|
Surface Load Label
|
Label Description
|
Structural
|
PRES
|
pressure
|
FREQ
|
frequency (harmonic analyses only)
|
|
Thermal
|
CONV[1]
|
convection
|
HFLUX[1]
|
heat flux
|
|
RAD
|
radiation
|
|
RDSF
|
surface-to-surface radiation
|
|
Acoustic fluid
|
FSI[2]
|
fluid-structure interaction flag
|
IMPD
|
impedance or admittance
coefficient
|
|
SHLD
|
surface normal velocity
|
|
MXWF
|
Maxwell surface flag or equivalent
source surface
|
|
FREE
|
free surface flag
|
|
INF
|
exterior Robin radiation boundary
flag
|
|
Magnetic
|
MXWF
|
Maxwell force flag
|
MCI
|
magnetic circuit interface
|
|
Electric
|
CHRGS
|
surface charge density
|
MXWF
|
Maxwell force flag
|
|
Infinite element
|
INF
|
|
High-frequency electromagnetic
|
PORT
|
number 1-50 for a waveguide
exterior port
|
SHLD
|
surface shielding properties
|
|
MXWF
|
Maxwell surface flag of equivalent
source surface
|
|
IMPD
|
surface impedance
|
|
Field-surface interface
|
FSIN[3]
|
field-surface interface number
|
Poromechanics
|
FFLX
|
Fluid flow flux
|
2.
For an acoustic analysis, apply the
fluid-structure interaction flag (Label = FSI) to only the FLUID29, FLUID30, FLUID220, and FLUID221 elements.
3.
For a fluid-solid interaction
analysis, apply the field-surface interface flag (Label = FSIN) twice: once for
the fluid side (FLUID141 or FLUID142 elements) and once for the solid side.
VALUE
Surface load value or table name
reference for specifying tabular boundary conditions.
If Lab = PRES, VALUE is the real component of the pressure.
If Lab = CONV, VALUE is typically the film coefficient and VALUE2 (below) is typically the bulk temperature. If VALUE = -N, the film coefficient may be a function of temperature and
is determined from the HF property table for material N [MP]. The temperature used
to evaluate the film coefficient is usually the average between the bulk and
wall temperatures, but may be user-defined for some elements.
If Lab = MCI, VALUE indicates current direction (-1; current flow into the
element face (IN), +1; current flow out of the element face (OUT). If Lab = RAD, VALUE is surface emissivity.
If Lab = PORT, VALUE is a port number representing a waveguide exterior port.
The port number must be an integer between 1 and 50.
If Lab = SHLD, VALUE is surface conductivity for high-frequency electromagnetics
and is surface normal velocity for acoustics.
If Lab = IMPD, VALUE is resistance in ohms/square for high-frequency
electromagnetics. For acoustics, VALUE is resistance in (N)(s)/m3 if VALUE > 0 and is conductance in mho if VALUE < 0.
If Lab = RDSF, VALUE is the emissivity value; the following conditions apply: If
VALUE is
between 0 and 1, apply a single value to the surface. If VALUE= -N,
the emissivity may be a function of the temperature, and is determined from the
EMISS property table for material N (MP). The material N does not need to correlate with the underlying solid
thermal elements.
If Lab = FSIN in a Multi-field solver (single or multiple code
coupling) analysis, VALUE is the surface interface number. If Lab = FSIN in a unidirectional ANSYS to CFX analysis, VALUE is not used unless the ANSYS analysis is performed using
the Multi-field solver.
VALUE2
Second surface load value (if any).
If Lab = PRES, VALUE2 is the imaginary component of the pressure. Imaginary
pressures can only be used by SURF153, SURF154 and SURF159, and can only be used for a full harmonic
analysis (HROPT,FULL), or by a
mode superposition harmonic analysis (HROPT,MSUP) if the mode
extraction method is Block Lanczos (MODOPT,LANB), PCG
Lanczos (MODOPT,LANPCG), or
Supernode (MODOPT,SNODE).
If Lab = CONV, VALUE2 is typically the bulk temperature.
If Lab = RAD, VALUE2 is the ambient temperature.
If Lab = SHLD, VALUE2 is relative permeability (defaults to 1.0) for
high-frequency electromagnetics and is the phase angle of the normal surface
velocity (defaults to zero) for acoustics.
If Lab = IMPD, VALUE2 is reactance in ohms/square for high-frequency
electromagnetics. For acoustics, VALUE2 is reactance in (N)(s)/m3 if VALUE > 0 and is the product of susceptance and angular
frequency if VALUE < 0.
If Lab = RDSF, VALUE2 is the enclosure number. Radiation will occur between
surfaces flagged with the same enclosure numbers. If the enclosure is open,
radiation will also occur to ambient. If VALUE2 is negative radiation direction is reversed and will occur
inside the element for the flagged radiation surfaces. Negative value of
enclosure number is applicable for FLUID141 and FLUID142 elements, to model radiation occurring
between surfaces inside the fluid domain.
If Lab = FSIN in a unidirectional ANSYS to CFX analysis, VALUE2 is the surface interface number (not available from within
the GUI).
If Lab = PORT, VALUE2 is not used.
Individual
nodes may not be entered for this command. The node list is to identify a
surface and the Nlist field must
contain a sufficient number of nodes to define an element surface. The loads
are internally stored on element faces defined by the specified nodes. All
nodes on an element face (including midside nodes, if any) must be specified
for the face to be used, and the element must be selected.
If all nodes
defining a face are shared by an adjacent face of another selected element, the
face is not free and will not have a load applied. If more than one element can
share the same nodes (for example, a surface element attached to a solid
element), select the desired element type before issuing the SF command.
The SF command applies only to area and volume elements.
For shell
elements, if the specified nodes include face one (which is usually the bottom
face) along with other faces (such as edges), only face one is used. Where
faces cannot be uniquely determined from the nodes, or where the face does not
fully describe the load application, use the SFE command. A load key of
1 (which is typically the first loading condition on the first face) is used if
the face determination is not unique. A uniform load value is applied over the
element face.
See the SFBEAM command for
applying surface loads to beam elements. See the SFGRAD command for an
alternate tapered load capability. See the SFFUN command for
applying loads from a node vs. value function. Also see the SFE command for applying
tapered loads on individual element faces. Use the SFDELE command to
delete loads applied with this command. Use the SFCUM command to
accumulate (add) surface loads applied with SF.
Tabular
boundary conditions (VALUE = %tabname% and/or VALUE2 = %tabname%) are
available for the following surface load labels (Lab) only: PRES (real and/or imaginary components),
CONV (film coefficient and/or bulk temperature) or HFLUX, and RAD (surface
emissivity and ambient temperature). Use the *DIM command to define a table.
This command is
also valid in PREP7.
Main
Menu>Preprocessor>Loads>Define
Loads>Apply>Electric>Boundary>AppImped_E>On Nodes
|
Main
Menu>Preprocessor>Loads>Define
Loads>Apply>Electric>Boundary>AppShield>On Nodes
|
Main
Menu>Preprocessor>Loads>Define
Loads>Apply>Electric>Excitation>AppSurfChar>On Nodes
|
Main
Menu>Preprocessor>Loads>Define Loads>Apply>Electric>Excitation>EMPorts>Exterior
Port>On Nodes
|
Main
Menu>Preprocessor>Loads>Define
Loads>Apply>Electric>Flag>AppInfinite>On Nodes
|
Main
Menu>Preprocessor>Loads>Define
Loads>Apply>Electric>Flag>AppMaxwell>On Nodes
|
Main
Menu>Preprocessor>Loads>Define Loads>Apply>Field Surface
Intr>On Nodes
|
Main
Menu>Preprocessor>Loads>Define
Loads>Apply>Fluid/ANSYS>Field Surface>On Nodes
|
Main
Menu>Preprocessor>Loads>Define
Loads>Apply>Fluid/ANSYS>Impedance>On Nodes
|
Main
Menu>Preprocessor>Loads>Define Loads>Apply>Magnetic>Flag>AppInfinite>On
Nodes
|
Main
Menu>Preprocessor>Loads>Define
Loads>Apply>Magnetic>Flag>AppMCI>On Nodes
|
Main
Menu>Preprocessor>Loads>Define
Loads>Apply>Magnetic>Other>AppMaxwell>On Nodes
|
Main
Menu>Preprocessor>Loads>Define Loads>Apply>Structural>Pressure>On
Node Components
|
Main
Menu>Preprocessor>Loads>Define
Loads>Apply>Structural>Pressure>On Nodes
|
Main
Menu>Preprocessor>Loads>Define
Loads>Apply>Thermal>Convection>On Nodes
|
Main
Menu>Preprocessor>Loads>Define Loads>Apply>Thermal>Heat
Flux>On Nodes
|
Main
Menu>Preprocessor>Loads>Define
Loads>Apply>Thermal>Radiation>On Nodes
|
Main
Menu>Preprocessor>Loads>Define Loads>Apply>Thermal>Surface
Rad>On Nodes
|
Main Menu>Solution>Define
Loads>Apply>Electric>Boundary>AppImped_E>On Nodes
|
Main Menu>Solution>Define
Loads>Apply>Electric>Boundary>AppShield>On Nodes
|
Main Menu>Solution>Define
Loads>Apply>Electric>Excitation>AppSurfChar>On Nodes
|
Main Menu>Solution>Define
Loads>Apply>Electric>Excitation>EMPorts>Exterior Port>On
Nodes
|
Main Menu>Solution>Define
Loads>Apply>Electric>Flag>AppInfinite>On Nodes
|
Main Menu>Solution>Define
Loads>Apply>Electric>Flag>AppMaxwell>On Nodes
|
Main Menu>Solution>Define
Loads>Apply>Field Surface Intr>On Nodes
|
Main Menu>Solution>Define
Loads>Apply>Fluid/ANSYS>Field Surface>On Nodes
|
Main Menu>Solution>Define
Loads>Apply>Fluid/ANSYS>Impedance>On Nodes
|
Main Menu>Solution>Define
Loads>Apply>Magnetic>Flag>AppInfinite>On Nodes
|
Main Menu>Solution>Define
Loads>Apply>Magnetic>Flag>AppMCI>On Nodes
|
Main Menu>Solution>Define
Loads>Apply>Magnetic>Other>AppMaxwell>On Nodes
|
Main Menu>Solution>Define
Loads>Apply>Structural>Pressure>On Node Components
|
Main Menu>Solution>Define
Loads>Apply>Structural>Pressure>On Nodes
|
Main Menu>Solution>Define Loads>Apply>Thermal>Convection>On
Nodes
|
Main Menu>Solution>Define
Loads>Apply>Thermal>Heat Flux>On Nodes
|
Main Menu>Solution>Define
Loads>Apply>Thermal>Radiation>On Nodes
|
Main Menu>Solution>Define
Loads>Apply>Thermal>Surface Rad>On Nodes
|
Nguồn :
Release 14.0 - © 2011 SAS IP, Inc. All rights reserved.
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