Transient Gas Cloud Data


As monitor regions have already been defined in the Tutorial 3 file, they are automatically updated when the transient simulation completes. You may also add monitor regions after simulations are complete and still view the transient results.


  1. Open the Gas Cloud Analysis window by selecting the icon from the toolbar or Project Menu.

  2. The Facility Monitor Region should already be selected. Double-click on the cell corresponding to the Equivalent Stoichiometric Volume LFL-100% for the transient simulation, a graph similar to Figure 15 should appear. If you select a simulation without transient data, the graph will appear with text stating "no transient data". Alternatively, you may select the cell and click the button.


    Tutorial 8 - Figure 15 - Viewing Gas Cloud Analysis transient data by double clicking a cell


  3. Similar to the Monitor Point Data, this graph and associated values at the varying times can be exported to excel.

  4. In the Gas Cloud Analysis window, change the Transient dropdown option to Max Value. What do you notice?


    Tutorial 8 - Figure 16 - Changing the table to display the maximum value achieved during the simulation


  5. For this case, the maximum value was achieved within 4 seconds of the release. As the release was directed towards a cross wind this can be expected. However, with more congestion near the leak having a larger gas cloud size later in the simulation (or even after ESD) is possible.



Continue to the next section to go over adding a shutdown time on a release.