Physical properties of an edge for problems of heat transfer.
Details
The LabelEdgeHT object represents physical data applicable to the edge label for heat
transfer problems.
When you need to set or modify physical parameters for the block label, you have to get the LabelEdgeHT
object using the Content property of the Label
object, modify the LabelEdgeHT object using its properties, and then put it back in the Label
object assigning your LabelEdgeHT to the Content property of your Label object.
The LabelEdgeHT object inherits methods and properties from its base class LabelEdge.
here the LabelEdge's properties take the following meaning:
If TRUE, defines the constant temperature boundary condition. The surface is assumed
to have a constant but unknown temperature value T=const.
With heat transfer problems, an edge label can be defined as a Dirichlet (first kind) condition,
or a constant temperature boundary condition, or one or more boundary conditions of following
kinds:
flux (second kind) boundary condition;
convective boundary condition;
radiation boundary condition;
In addition to the generic properties of LabelEdge listed
above, the LabelEdgeHT object provides methods for setting and reading those special
kinds of boundary condition:
Returns TRUE if the convection boundary condition is set, otherwise returns FALSE.
In the method returning TRUE, the optional parameters Alpha and T as double
take the value of film coefficient and the temperature of contacting fluid
medium respectively.
Sets or removes the convection boundary condition.
The first parameter bSet as BOOL sets the boundary condition if it is TRUE
and removes otherwise. The Alpha parameter contains the value of film
coefficient and T - the contacting medium temperature.
Returns TRUE if the radiation boundary condition is set, otherwise returns FALSE.
If the method returns TRUE, the optional parameters Beta and T as double
take the value of emissivity coefficient and the ambient radiation temperature
respectively.
Sets or removes the radiation boundary condition.
The first parameter bSet as BOOL sets the boundary condition if it is TRUE
and removes otherwise. The Beta parameter contains the value of emissivity
coefficient and T - the ambient radiation temperature.
Returns TRUE if the second kind boundary condition is set, otherwise returns FALSE.
If the method returns TRUE, the optional parameter Flux as double takes
the value of the normal component of the heat flux.
Sets or removes the second kind boundary condition.
The first parameter bSet as BOOL sets the boundary condition if it is TRUE
and removes otherwise. The Flux parameter contains the normal component of
the heat flux.
In the following example we create three new labels for the edges. For one of them called
"T=const" we set the boundary condition to the first kind with temperature value 373.
For the second edge "Convective", a convection boundary condition is defined, and for
the third one - the radiation condition.
Dim lb As QuickField.Label
Dim lbCnt As QuickField.LabelEdgeHT
Set lb = prb.Labels(qfEdge).Add
lb.Name = "T=const"
Set lbCnt = lb.Content
lbCnt.Dirichlet = 373#
lb.Content = lbCnt
Set lb = prb.Labels(qfEdge).Add
lb.Name = "Convective"
Set lbCnt = lb.Content
lbCnt.SetConvection True, 0.0115, 95
lb.Content = lbCnt
Set lb = prb.Labels(qfEdge).Add
lb.Name = "Radiative"
Set lbCnt = lb.Content
lbCnt.SetRadiation True, 0.2, 500
lb.Content = lbCnt