Thermal - Options

The Thermal dialog box lets you select the desired options for a thermal study.

To access the Thermal options dialog box, right-click the icon of a thermal study in the Simulation study tree and select Properties.

Solution Type

Transient Check this button to run transient thermal analysis.
Total time Specifies the total time of interest (T) for a transient analysis. Default is 1.0 sec.
Time increment Specifies the increment of time (Δt) for transient solution steps. Default is 0.1 sec. The program calculates the solution at Δt, 2(Δt), 3(Δt), 4(Δt),..., and T, where Δt is the time increment and T is the specified total time.
Initial temperatures from thermal study Uses the temperatures calculated from a thermal study (steady state or transient) as an initial condition for the transient thermal study. Select the desired Thermal study and specify the Time steps at which you want to use the temperature profile as an initial condition (for steady state thermal studies, the Time steps field is set to 1).
Steady State Check this option to specify steady state thermal analysis.

Fluid convection option

Include fluid convection effects from SOLIDWORKS Flow Simulation Check this option to read the convection coefficient calculated from a completed Flow Simulation study on the same configuration from a file. Select the desired Flow Simulation Result Files (*.fld) that has been generated by Flow Simulation . The model name, configuration name, and flow iteration number associated with the specified file are displayed. This option is not available for 2D simplification studies.
To view a plot of the imported convection on the model, right-click the convection icon in the Simulation study tree and select Show Plot. The model must be meshed before the plot option is available.

Solver

Lets you specify the solver to be used when running the study.

Automatic Check this option to allow the software to choose the solver to be used.
Direct sparse Check this option to use the Direct Sparse solver when running the study.
FFEPlus Check this option to use the FFEPlus solver when running the study.
Results folder Accept the default folder or browse to select another location for the results.
Advanced Options Switches to the Advanced tab of this dialog box.

Recommended Time Increment for Thermal Studies

The recommended time step size Δt for a transient thermal analysis is related to element conduction length and material properties.

The larger the thermal diffusivity, the smaller the Δt and element length should be. The recommended time step is given as:

Δt ≤ δ2 ∕ 4α

α = thermal diffusivity = K / ρc (Units are length2 / time)

δ = conducting length (for line elements this is the element's length, for plane or volume elements, it is the diagonal of the inscribed circle or sphere)

K = conductivity

ρ = mass density

c = specific heat