Solar Heating Dialog

Solar heating plays an important role in the design of homes and buildings. Engineers and architects need to understand and account for the effects of solar heating on the energy performance and efficiency of the structures and occupied spaces they create.

In Autodesk® CFD, you can simulate the effect of solar heating both externally, such as on a neighborhood or urban scene, and internally, such as the interior of occupied spaces.

Solar heating can be run steady state to study the temperature distribution at a moment in time, or it can be run transient to study the temperature time history over several days and nights.

Solar Heating works with the Radiation solver, and supports radiative heat transfer through transparent media. Solar heating also supports the effect of shadowing on other objects. You can specify specific geographical locations or input latitude and longitude. You can also specify the date, time, compass direction, and object orientation relative to the sky. Autodesk® CFD provides a full report of the radiative energy balance during and after the analysis.

Step 1

To run a solar heating simulation, enable both Heat Transfer and Radiation on the Physics tab of the Solve dialog. Click the Solar heating button. On the Solar Heating Dialog, check Enable Solar Heating.

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

If you are simulating solar heating within a structure and the model includes solar windows or solar walls:

Set the Time variation to either Steady State or Transient.
If you select Steady State, specify the Ambient Reference Temperature. This is the temperature assigned to the outer surfaces of the model. Note that heat transfer boundary conditions (such as a film coefficient or temperature) override the Ambient Reference temperature.
If you select Transient, specify how the Ambient Temperature varies with time using the Time Curve table.

Step 6

Click the OK button to close the dialog.

Example of defining a Solar Analysis