Flow/Thermal Effects

When considering flow and thermal effects in a nonlinear study, notice the following differences:

If you acquire a single temperature profile, or pressure profile from COSMOSFloWorks, the program associates it automatically with the default linear curve. The temperature profile is varied linearly until it reaches the acquired values at the end of the solution period.
If you select a transient thermal study, you have two options:

Specify a particular time step to acquire the temperatures. The temperatures are applied linearly as specified by the solution time parameters.
For each nonlinear step, use temperature from corresponding time of transient thermal analysis.

The meshes of the thermal and nonlinear studies must be identical. For this functionality to work properly, the time range for the solution should be similar for the thermal and nonlinear studies. Using a different time range for the nonlinear study may lead to incorrect results.

In the COSMOS AnalysisManager tree, right-click the icon of a static, buckling, or nonlinear study and select Properties.

The properties dialog box of the study opens.

Click the Flow/Thermal Effects tab.
In the Thermal options box, do the following:

Select one of the following options:

Input temperature.
Temperature from thermal study. Select a thermal study from the list. If you select a transient thermal study, specify a time step of the temperature profile you want to use.

For each nonlinear time step, use temperature from corresponding time of transient thermal analysis.

Temperature from COSMOSFloWorks. Select the COSMOSFloWorks result file (*.fld).

In the Reference temperature at zero strain, select a unit for the temperature then type a value for the temperature.

Click OK.

In the COSMOS AnalysisManager tree, right-click a static, buckling, or a nonlinear study icon and select Properties.

The properties dialog box of the selected study opens.

Click the Flow/Thermal Effects tab.
Do the following:

To import temperature, check Temperature from COSMOSFloWorks and browse to select the desired COSMOSFloWorks Result File (*.fld).

The model name, COSMOSFloWorks configuration name, and the time step associated with the temperature profile appear.

To import pressure, check Include fluid pressure effects from COSMOSFloWorks under Fluid pressure option and browse to select the desired FloWorks Result File (*.fld).

Click OK.

Flow/Thermal Effects

If an unrestrained body is subjected to a change in temperature, it will expand or contract freely as it is heated or cooled. The change in temperature causes strains but no stresses. If the body is prevented from expansion or contraction freely, stresses are induced. The induced stresses are equivalent to those required to deform an equivalent unrestrained body similarly.

It is important to include the contribution of temperature changes to stresses for restrained models. The coefficient of thermal expansion material property (KX) is required to consider this effect. You need to specify the reference temperature associated with the stress-free condition.

For proper acquisition of temperature and pressure loads from COSMOSFloWorks, the active study and the COSMOSFloWorks study should be associated with the same configuration.

Thermal Options

When using this option, make sure to specify temperatures on components or shells. Specifying temperatures on the boundary only may not be practical since a temperature of zero is assumed at all other locations. If you define temperature on boundary only, you may need to create and solve a thermal study first to compute temperatures at all nodes.

You can use design scenarios to automate the calculation of static results based on temperature profiles taken from solution steps of a transient thermal study.

Reference temperature at zero strain. Sets the temperature at which no strains exist in the model.

Fluid Pressure Options

Refer to the COSMOSFloWorks online help for the procedure to create the *.fld file.