#### Further Information

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• ### How can I reactivate an expired trial license of RWIND Simulation on a single-user computer?

The RWIND Simulation program is protected against unauthorized use. Before you buy the program, you can use a limited trial license to test all program features before the purchase. After this trial period, the program switches to a limited demo mode and deactivates the function to activate a new trial license. If you indicate a justified reason, the program can be authorized again with a temporary trial license via the e-mail activation.

For this, proceed as follows:

1. Run RWIND Simulation "As Administrator." To do this, right-click the RWIND Simulation icon and select "Run As Administrator."

2. Click the "Activate Now" button to confirm the authorization check.

Then, the "RWIND Simulation 1.xx Demo Authorization Status" dialog box appears.

3. In the "RWIND Simulation 1.xx Demo Authorization Status" dialog box, select the "Software Key" option in the Authorization Method area and click the "Activation via E-Mail" function in the lower part.

This opens the "Activation by E-Mail" dialog box.

Furthermore, enter a user-defined description of the workstation to be activated under "Description of Workspace" and the RWIND Simulation level with an expiry date of the activation to be carried out under "Required Authorization."
Then, click the "Generate Request Code" button to confirm your entries.

The "RWIND Simulation 1.xx Demo" dialog box appears.

5. Check the data entered in the "RWIND Simulation 1.xx Demo" dialog box. If they comply, click "OK" to confirm the dialog box.

This opens the "Activation by E-Mail" dialog box.

6. The "Activation by E-Mail" dialog box consists of three parts. In the "Step 2" tab, the required request code is displayed on the left. Copy this text block to the Windows clipboard by clicking the "Copy Request Code" button and then paste the code into a blank e‑mail with [Ctrl]+[V] or the Windows paste function. Send this e-mail to support@dlubal.com with the justified reason for a new trial period for further processing.

7. You will receive an activation code from us. In the dialog box, go to the "Step 3" tab and enter this code in the "Activation Code" text box.
Then, click the "Activate Now" button to run the activation process.

After the successful authorization, you receive a confirmation message and can test the program for the specified trial period without any restrictions. After the expiration of the trial period, the program automatically switches to the limited demo mode.

• ### How can I access the RWIND Simulation program from RFEM, assuming that it is possible to transfer a 3D model created in RSTAB?

RWIND Simulation is exclusively compatible with RFEM due to CFD modeling which requires a finite element calculation. The model created in RSTAB can be opened in RFEM. The wind load parameters can be defined in the RFEM dialog Simulate and Generate Wind Loads.

At the bottom of the Wind load tab, it is possible to stay and automatically generate the loads for the corresponding load cases after the CFD calculation has been run in the background.

If you would rather perform the wind simulation in RWIND, click the button Open in in the Load cases tab of RWIND Simulation.

To obtain the trial version of RWIND Simulation, proceed as indicated in this FAQ .

• ### What is the formula used to calculate the ASCE 7 wind velocity profile?

The wind velocity profile in RWIND Simulation according to the ASCE 7-16 standard [1] is calculated based on Eq. 26.10-1. The coefficients and basic wind speed in this equation below are incorporated in the wind pressure equation.

Velocity wind pressure (imperial): qz = 0.00256 Kz Kzt Kd Ke V2

We must reference this equation to calculate the inlet velocity relative to elevation for the RWIND Simulation CFD wind tunnel. To consider only velocity rather than pressure from this equation, the basic wind speed is multiplied by the square-root of each coefficient. Notice the velocity variable in Eq. 26.10-1 is squared which requires the square root of the coefficients to be considered.

$Inlet\;velocity\;=\;V\sqrt{K_e\;\cdot\;K_{d\;}\cdot\;K_z\;\cdot\;K_{zt}}$

Because the ASCE 7-16 standard does not address wind CFD analysis and magnitude of the required inlet velocity, it is difficult to draw comparisons. Therefore, this is the closest estimate for calculating the RWIND Simulation inlet wind velocity per the code.

• ### When trying to perform a calculation, I get the message "The path to RWIND Simulation working directory cannot contain any non-ASCII characters." What can I do?

The working directory is a local path where the data of the currently opened structure is temporarily handled and saved. It consists of the first letters of the file. Only ASCII characters may be used.

The non-ASCII characters are, for example, "ä," "ö," and "ß."

To avoid this problem, replace the special characters in the file name by the ASCII characters, such as "ae" and "ss" instead of "ä" and "ß." When you open the file again, the message will no longer appear.
• ### In RWIND Simulation, I would like to rotate the model, adjust the wind tunnel, and then rotate the model again. How can I prevent the rotation point of the model from being changed?

In RWIND Simulation, you can manually adjust the model position and the model rotation. To do this, simply select Model → Edit in the navigator, and then enter the desired rotation angle in the Position tab. In this case, the rotation is carried out without changing the displacement.

If not, contact us via our free e-mail, chat, or forum support, or send us your question via the online form.

#### First Steps

We provide hints and tips to help you get started with the main programs RFEM and RSTAB.

#### Wind Simulation & Wind Load Generation

With the stand-alone program RWIND Simulation, wind flows around simple or complex structures can be simulated by means of a digital wind tunnel.

The generated wind loads acting on these objects can be imported to RFEM or RSTAB.

#### Your support is by far the best

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