A new feature has been added to Solaria to simulate a moving heat source. This would be used to simulate the sun moving across the sky. A solar insolation calculator has also been added to provide an easy means of adding accurate time dependent solar heat flux to your model. Convection to a time dependent ambient temperature and radiation to a time varying sky temperature is easily added to accurately simulate the complete environment. This feature works with both solvers.
In the Add>Heat Load>Surface dialog, a Moving Source area has been added. As before, check Select Vector Node and select a node in the model that defines the starting location of the source, or the sun. Next, check Has moving source. Enter the Angle of rotation, in degrees, and the Duration, in model units of Time, of the travel. Next define the plane the source is to rotate on. In the example below, the sun will rotate on the XY plane, it will go 180 degrees over a 12 hour 43,200 seconds) period. This information is saved with the model. At the bottom of this page is an animation of this situation on a radome.
Simulating a moving heat source (like the sun)
After the Surface Heat is added, you can animate how the surface vectors will change with time. Move the Vector node, change the plane or the angle then animate to see the effect before solving.
To go along with this, a solar insolation calculator has been added. Go to Model>Arrays>Calculate Solar Insolation. Enter the Month and Day of the month you want to simulate. The Day of the year will be calculated and displayed. Next enter the Start time of day, where the calculations start. The use of the Use all data checkbox is described below. Increment time defines how often calculations are performed.
If you know the latitude of the location you want to simulate then you can enter it. The drop down list contains 250 cities around the globe. Just select the city and its latitude will be entered.
You can hit the Plot Data button to view the Insolation. If Use all data is not checked then non-zero insolation values are not included in the data. This way you can simulate what is happening during the heating period. When you create array data, the Time data starts at the first point. For example, for the data plotted below, time zero in the array data will be at the 7 hour time shown.
The following shows the array created from the plotted data above. Notice that when the array data is created it is converted into model units. Make sure that you have defined the model units in Model>Units. After the array is created, just go into the property table for the heat source and reference the array. Remember that the array has incident energy, NOT absorbed energy. So the factor in the property should be the surface absorptivity.
If you want 24 hour data then just check Use all data.
You can enter a finer Increment time to include more data points, for a maximum of 200.
NOTE: After the array is generated remember to now reference the array from the Property that the Surface Heat Load references. Again, the heat flux in the array is incident to the surface. The value in the property table should be the solar absorptance value of the surface material. The heat load applied to a particular surface during the transient simulation is the Cosine of the angle between the surface and a vector towards the source at that point in time, times the interpolated value of the array data, times the value in the referenced Property, times the Factor defined in the Add>Heat Load>Surface dialog when the heat load was defined. This last value defaults to 1.0. The heat load to every surface is redefined every iteration during the simulation.
Below is an animation that was created by the Solaria Results>Animate Temperature feature. The source is moving with time as is the flux.
Below shows the path of the Source Node when the transient simulation is running. Note that the path is a constant radius around the 0, 0, 0 location in the model. In the case shown below, the radome model is sitting on the ground so the model should be moved placing the 0, 0, 0 location at its base.