Hello SIMULIA Community,

I am working on a CFD Flow Analysis in the 3DEXPERIENCE platform and am stuck on a specific step related to mesh assignment.

My Goal: Run a steady-state CFD simulation on a complex internal flow geometry using a high-quality hex mesh.

What I have done:

1. I successfully partitioned the complex fluid volume using the appropriate tools (e.g., Partitioning/Idealize) to make it sweepable.
2. I went to the Meshing App and successfully generated a Parttition Hex-Mesh on the partitioned geometry. The mesh quality is reported as good.nut 
3. The mesh object appears in the Specification Tree.
4. when i use hex domaint funtion  mesh is  work but when i use partition function now hat i should  exactl CFD 

The Problem: When I return to the Flow Analysis Scenario, the Simulation Assistant (under the Results or Simulate step) displays the error: "No mesh has been assigned to the fluid domain."

The software is not automatically linking the generated mesh to the Fluid Domain definition in the physics setup.

My Question: I am looking for the specific command or workflow (including the name of the tool, button, or menu item) that is required to explicitly associate my generated Hex-Dominant Mesh with the existing Model Fluid Domain definition in the simulation scenario.

Could someone please point me to the required command/tool name?

I have attached a screenshot  showing the error message in the Simulation Assistant.

Thank you in advance for your guidance!