COMSOL 6.4 - Updating and Solving a Model Using Excel® Macros

Updating and Solving a Model Using Excel® Macros

In this section you will find several examples that illustrate some of the possible work flows when using the COMSOL API for VBA.


	Some knowledge in VBA are required to run the examples. For more information please refer to the section Before You Start.

This example reuses the worksheet described in the section Working with COMSOL® Models in Excel® in the Introduction to LiveLink™ for Excel® manual. The steps below show how to write commands that automatically update the model with the settings in the worksheet, compute the solution and update the results data extracted in the worksheet.

When writing a subroutine in VBA the cell comment generated using the COMSOL toolbar are not usable. Enter the full command using the COMSOL API to reproduce the same behavior.

To get ready with the examples follow the steps below.

Start Excel, in the tab, click .

In your COMSOL Multiphysics installation directory, find the folder models/LiveLink_for_Excel/Tutorials.

Select the file busbar_llexcel.xlsx and click the button.

You can see in cell range B2, the full name of the model MPH file that is linked to the workbook. In the first worksheet you can assign value to model parameters and parameters sweep. It also contains the value of the maximum temperature in the busbar for the different parameter sweep values. The second worksheet contains the joule heating data interpolated at point coordinates defined in cell range A3 to C20.

Go to the Excel menu and select . In the COMSOL backstage view click button

and select

. You will be asked if you want to replace the contents of the destination cell, click OK.

When opening the linked model for this file, COMSOL will automatically search for the model busbar_llexcel.mph in the Application Library folder. If you do not have this model you need to specify the location. Find the folder applications/LiveLink_for_Excel/Tutorials. Select the file busbar_llexcel.mph and click the Open button.

The COMSOL Multiphysics server starts and loads the model file busbar_llexcel.mph that is linked to the worksheet.

In Excel press Alt+F11 keys to open the VBA editor.

In the VBA editor, go to menu and select .

In the editor type:

Sub busbarUpdate()

and press Enter key to get the end subroutine line automatically added to the script.

To run the macro a convenient way is to create a button. To proceed you need first to enable the Developer tab in the Excel ribbon.

In Excel, go to the tab and select .

In the window, select and on the right side of the window under select .

Click .

Go to the tab and click .

Under select and draw the button in the worksheet.

In the window that just pops-up, under the list select . Click .

You now have a button in the worksheet that runs the macro you will write in the example below. You can remove the inserted image and change the text in the button so that the worksheet looks like in the image below.


	The worksheet including the full example code is available at XLSM-format in the LiveLink™ for Excel® Application Library LiveLink_for_Excel/Tutorials/busbar_llexcel.xlsm

In order to work with a COMSOL model it is necessary to use the class ModelUtil, which is part of the COMSOL API. In addition to ModelUtil there is a new object that is part of LiveLink™ for Excel®, which is called ComsolUtil. This object provides extra utilities - such as the ability to start a COMSOL Multiphysics server and create the RibbonUtil object where you can access the ribbon functionalities.

Make sure you have set the COMSOL references in the VBA project, in the Visual Basic for Applications window, under Tools select References. In the Available References list, select ComsolCom 6.4 and click OK.

Type the command at the line after the subroutine declaration line Sub busbarUpdate().

Load the ComsolUtil, the ModelUtil, and the RibbonUtil objects.

Dim ModelUtil As ModelUtil

Dim ComsolUtil As ComsolUtil

Dim RibbonUtil As IRibbonUtil

Set ModelUtil = CreateObject("comsolcom.modelutil")

Set ComsolUtil = CreateObject("comsolcom.comsolutil")

Set RibbonUtil = ComsolUtil.GetRibbonUtil

To allow long running jobs enter the command:

ComsolUtil.TimeOuthandler True

Open the linked model only if the ribbon is not connected to the COMSOL server.

If Not RibbonUtil.IsConnected Then

RibbonUtil.OpenLinkedModel

End If

Set a link with the model, with the tag Model, available on the COMSOL server.

Set Model = ModelUtil.model("Model")

The cell range A6 to D6 define both the value and the unit for the model parameter L.

To update the model parameter defined in the cell range A4 enter:

Sheets("Sheet1").Activate

Range("A4").Select

RibbonUtil.UpdateDefinitions

The worksheet contains values for the busbar width (wbb) and the applied voltage (Vtot) as sweep parameter. In this example, the sweep parameters cannot have more than 5 value each.

Keep only the fifth first column for both sweep parameters:

Range("G9:J10").Clear

To update the parametric sweep parameters defined in the cell range A8 enter:

Range("A8").Select

RibbonUtil.Sweep "std1", ,True

To enable the progress bar and compute enter:

ModelUtil.ShowProgress True

Model.get_study("std1").Run

Display the third plot group and insert the corresponding image in L4.

Model.get_result("pg3").Run

Range("L4").Select

RibbonUtil.InsertGraphics "pg3"