Thermal Convection
In thermal analysis, define a convective heat exchange condition on faces and spots.
The convection coefficient defines the rate of heat transfer between the bulk fluid (liquid or gas, buoyant or moving) and a surface of your model. The convective coefficient is equal to the heat rate per unit area per unit temperature difference between the model surface and the bulk fluid.
Ambient temperature value specifies the temperature of the bulk fluid, which is assumed to remain constant during the analysis.
 In the Project Tree, click on a Thermal analysis branch to open the Analysis Workbench.

On the workbench toolbar, click the
(Convection) icon.
The Thermal convection dialog will open.
 Specify which type of entity will have constraints applied.
 Optional: If applying to Faces, you can select the Add tangent faces check box.
 Optional: If applying to Spots, create new spots by clicking Create new spot.
 On the modeling window, click to select specific parts on the model.
 Use the dropdown menus to specify Temperature units and Convection coefficient units.
 In the text boxes, specify Convection conditions.
 For thermal transient only, choose the time function for temperature.

If Use temperature dependent properties is checked in
thermal transient setup, input the convective heat transfer coefficient in one
of the following ways.
Table 1. Type Definition Constant Enter a constant value for convective heat transfer coefficient. Time dependent Convective heat transfer coefficient is defined as a value varying with time. Choose an existing time function or create a new time function to define the coefficient. Temperature dependent Convective heat transfer coefficient is defined as a value varying with temperature.  Choose the temperature for the coefficient function.
Available options are:
 Body temperature
 Ambient temperature
 Average temperature [i and ii]
 Temperature difference [Absolute difference between i and ii]
 Click Create.
 Import the function using CSV file or manually
create it.Note: The file CSV contents must have a header row followed by two or more rows of data. Each row has two values. Values must be separated with commas. The first is temperature and the second is convectioncoefficient or convectionheattransfercoefficient.
 CSV file format example
 Temperature,convectioncoefficient
 Choose the temperature for the coefficient function.
Available options are:
 Click OK to create.