Troubleshooting SOLIDWORKS Flow Simulation: Stuck on ‘Preparing Model’ or ‘Meshing in Progress’

If you’re using SOLIDWORKS® Flow Simulation or FloXpress™ and find that your projects are stuck indefinitely on the “Preparing model…” status in the Solver Monitor or the “Meshing in progress” step in FloXpress, you’re not alone. This is a common issue that can be frustrating, but fortunately, there are steps you can take to resolve it. In this blog, we’ll explore the symptoms, causes, and solutions to get your simulations running smoothly again.

Symptoms of the Issue

• The Solver Monitor shows the status “Preparing model…” indefinitely for every project you run.
• FloXpress analyses never progress beyond the “Meshing in progress” step.

What Causes This Issue?

1. Firewall or Antivirus Interference
   The problem is often related to your computer’s firewallor antivirus software. These programs can block certain processes required by SOLIDWORKS Flow Simulation or FloXpress, even when solving locally. Specifically, these processes need access to the TCP protocol to function properly.

2. Large or Complex Models
   If the issue only occurs with large or complex models, it may be related to the model itself. Complex geometry or a high number of components can overwhelm the meshing process, causing it to stall at the “Preparing model…”or “Meshing in progress” This is especially common when using CAD Boolean, which may struggle with intricate designs.

How to Fix the Issue

Step 1: Confirm the Issue

Before diving into solutions, confirm whether the issue occurs with every model or only specific ones. To test this:

1. Use a simple model.
2. Run the simulation to see if it completes meshing and solving quickly.

If the issue persists with even simple models, it’s likely a system or environment-specific problem. If it only occurs with large or complex models, the issue is likely related to the model itself.

Step 2: Simplify Meshing for Large or Complex Models

If the issue only occurs with large or complex models, the problem may lie in the meshing process. To resolve this:

1. Switch from CAD Boolean to Preprocessor Boolean or Mesh Boolean. These options are better suited for handling complex geometry and can simplify the meshing process.
   
2. Reduce the complexity of your model by simplifying geometry or breaking it into smaller components.
3. Refine your mesh settings to balance accuracy and computational efficiency.

Step 3: Check Firewall and Antivirus Settings

If the issue occurs universally, your firewall or antivirus software may be blocking critical processes. Here’s what you can do:

1. Contact your IT department or system administrator for assistance. They can:
   • Check activity logs for the software.
   • Adjust firewall or antivirus settings.
   • Contact the third-party software vendor if needed.
2. Use Windows Resource Monitor > Network to verify TCP activity for efdsolver.exe.
3. If the issue appeared after a recent update, it’s possible that security settings were modified. Adjust your security software to allow the following processes access to the TCP protocol:
   • efdsolver.exe
   • dispatcher.exe

Step 3: Alternative Solution for SOLIDWORKS Flow Simulation

If you cannot adjust your firewall or antivirus settings, try this workaround:

1. In the SOLIDWORKS Flow Simulation Run dialog, go to the Cores and memory usage section.
2. Click the menu to the right of Run at: and select Add computer.
   
3. In the Add Computer dialog, type localhost in the Name field and 30950 in yhr zport field click Add (no need to change the port number).
   
4. In the Cores and memory usage section, click the menu to the right of Run at: and select localhost:30950. Click Run.