How to Simulate Fluid-Structure Interaction Using 3DEXPERIENCE

Simulation tools on the 3DEXPERIENCE platform empower designers and engineers to solve fluid-structure interaction (FSI) problems. With advanced meshing capabilities, robust solvers, and cloud computing, 3DEXPERIENCE simulation can streamline your product design process.

The computational fluid dynamics role, Fluid Dynamics Engineer, combined with a finite element analysis role, Structural Mechanics Engineer, can be used to simulate the fluid-structure interactions. Using both tools can take the guesswork out of your design when dealing with coupled stress coming from traditional structural loads and fluid interactions.

What is Fluid Dynamics Engineer?

The Fluid Dynamics Engineer (FMK) role on the 3DEXPERIENCE platform leverages advanced computational fluid dynamics (CFD) to simulate fluid flow, heat transfer, and evaluate the real-life performance of product designs. Key features for this cloud-based simulation include high-fidelity meshing that captures the boundary layers more accurately, as well as including various simulation models, such as Spalart-Allmaras for turbulence modeling.

What is Structural Mechanics Engineer?

The Structural Mechanics Engineer (SSU) role focuses on assessing the structural integrity of products using the industry-proven Abaqus solver in a unified cloud-based environment. Rather than being tied to system resources, this role enables users to offload simulation solving to the 3DEXPERIENCE cloud to quickly solve complex problems.

How to Simulate Fluid-Structure Interaction

Combining these roles, the 3DEXPERIENCE platform excels in fluid-structure applications by allowing seamless integration of fluid and structural simulations. Using 3DEXPERIENCE enables your team to quickly switch between simulation domains and fully validating your designs.

Setting Up the Flow Analysis

An external flow analysis is set up for a billboard assembly subjected to wind on the large front face of the model. This is to simulate a large gust of wind and the resultant effect on the billboard, ensuring it holds up to adverse conditions.

Initial Fluid Conditions

A velocity inlet condition is set up in the X direction so that the fluid is moving 40m/s and striking the front of the billboard. On the opposite end of the computational domain, a static gauge pressure of 0 N/m² is defined so that the fluid will accurately move in the simulation.

Defining a velocity inlet initial condition

To simulate air movement around the billboard, a slip condition is specified around the sides of the billboard where the wind blows. The default no-slip condition is specified at the base to represent the grounded base of the structure supporting the billboard.

Setting up slip walls for the study

Meshing the Fluid Domain

In this instance, a hex-dominant mesh is used to accurately simulate the fluid domain. Additionally, a coarse mesh with three additional boundary layers is defined to give more precise results along the boundary between fluids and solids.

The meshed fluid domain

Using Port Regions

Since the fluid pressure results from the CFD analysis are to be used for structural analysis, a Port Region is defined, which allows users to couple the structural step sequence with the flow step sequence. This coupling enables the fluid-structure interaction simulation to run seamlessly by exchanging data between the fluid flow and the structural simulation simultaneously.

Defining Port Regions for smooth data transfer

If port regions were not set up before running the analysis, users can export the results, in this case, gauge pressure values, from the surfaces after the analysis is completed.

Flow Study Results

After setting up the study and running the simulation, the results are available for review. Different types of plots can be generated to gain key insights into the study. For example, gauge pressure section plots and velocity streamline plots can quickly show what is happening based on the input conditions.

A fluid velocity plot for the billboard study

Setting Up the Structural Analysis

Once the flow analysis has been completed, the results can be transferred to a structural simulation as applied loads. If the Port Region has been defined in the flow analysis, users can directly point to that specific flow simulation model.

As a result, the gauge pressure is mapped to the surfaces defined in the Port Region.

Using an existing Port Region to connect studies  

If the Port Region was not defined, users can use the option Mapped spatial data to use the previously exported gauge pressure data.

Mapping studies without a Port Region defined

Confirming Study Mapping

In either approach, there is an option to Plot Data that allows users to see if the data is mapped correctly. In the event it is not mapped properly, you can go back to the flow study to adjust the Port Region and re-export.

Plotting the Port Region on the model

Structural Study Results

After setting up the study and running the simulation, the results are available for review. Different types of plots can be generated to gain key insights into the study. For example, von Mises Stress and hydrostatic pressure can be plotted to quickly show what is happening based on the input conditions.

Von Mises Stress plotted as a result of the study

Comparing 3DEXPERIENCE and Desktop Simulation

The results obtained from the 3DEXPERIENCE simulation tools are comparable to the desktop SOLIDWORKS Flow Simulation and SOLIDWORKS Simulation. This makes each toolset a viable way to test your models.

However, the simulation tools on 3DEXPERIENCE offer more robust capabilities for complex fluid-structure interaction studies and can leverage high-performance cloud computing. Additionally, all simulation activities are linked, tracked, and managed with 3DEXPERIENCE data management.

Regardless, engineers can ensure their designs are robust enough and simulate how fluids interact with their structures to find the optimal design.

To learn more about using 3DEXPERIENCE SIMULIA for simulation, click here.