Solar Heating Dialog

Solar heating plays a significant role in the reliability and performance of many mechanical and electronic devices that are subjected to outside environmental conditions. In some situations, the worst-case solar loading during the hottest part of the day is of interest. In other situations, the intent is to understand the periodic temperature variation that occurs from diurnal heating (multiple cycles of day and night).

The Solar Heating functionality allows study of both scenarios. Solar heating can be run as a steady state analysis to learn the temperature distribution caused by solar loading at a particular instant in time. Alternatively it can be run as a transient analysis to study the time history of the temperature distribution over several days and nights.

The Solar model only works in conjunction with the new radiation model, and as such supports radiative heat transfer through transparent media. With solar heating, the effect of shadowing on other objects is also supported. The Solar Heating dialog allows for specification of specific geographical locations as well as input of latitude and longitude. The date, time, compass direction, and object orientation relative to the sky are also specified. A full report of the radiative energy balance similar to the reports shown in the previous section is provided during and after the analysis.

Radiation must be enabled to run a solar heating analysis. Solar heating is not supported unless both Heat Transfer and Radiation are enabled on the Options dialog.

To configure solar heating, click Solar Heating on the Options dialog box.

Note: Note that this button is not active unless both Heat Transfer and Radiation are enabled.

Step 1

Check the Enable Solar Heating box to include solar heating in an analysis. The dialog is grayed out unless this box is checked.

Step 2

Select the geographical location. There are two ways to do this:

Select the country and city from the drop-down menus.
Check the Manual box, and enter the Latitude and Longitude coordinates and the offset from Greenwich Mean Time (in the GMT box). The GMT offset is used to accurately determine the time zone.
- The latitude must be between -90 and 90 degrees.
- The longitude must be between -180 and 180 degrees.
- The GMT must be between -12 and 12.

Step 3

Set the Date and Time.

Change each value by clicking on it, and use the up and down arrows to modify the value.

Direct entry in these fields is not supported.

Note: All times are considered to be Standard Time. This is because Daylight Savings Time is not supported due to the wide variation of its use throughout the world.

Step 4

Specify the orientation of the model.

The Compass Direction defines which way the model is facing.
The Celestial Orientation defines which way is up by selecting either the direction of the sky or the ground.
For both directions, select the convenient direction or orientation, and select the direction from the adjacent menu.
Set the direction either with a Cartesian axis or by selecting a direction graphically on the model.

Step 5

Click the OK button to close the dialog.

Example of defining a Solar Analysis