Fluid-Structure Interaction (FSI) Consulting

Understanding the interaction of a movable or deformable structure with an interior or adjacent fluid flow is critical to the design and operation of several modern engineering technologies. Our in-house fluid engineering experts can assist your team with steps ranging from preliminary design and software training to advanced laboratory or on-site (in the field) physical testing.

Fluid-Structure Interaction (FSI)

For multiphysics computational analysis, fluid-structure interactions (FSI) rank among the most difficult problems.

A fluid is used to load a deformable structure; the type of deformation has an impact on the fluid flow, which has an impact on the deformation response. As a result of their close relationship, deformation and fluid flow are thought to be too complex to be solved analytically and instead require computer analysis.

These multiphysics interactions can be as simple as coupling of solid body temperatures for prestressing, to changing fluid volume due to rigid motion of solid bodies, to tightly coupled flexible deformation of the solid bodies reacting to the spatially and time-varying fluid pressure and shear forces.

 Recent CFD Projects in Fluid-Structure Interaction (FSI)

High-Pressure Pump

Investigated the fluid failure mechanism and redesign of a high-pressure reciprocating pump used to inject water into the reservoir in the fracking process. The model captured the transient multiphase flow as the pump piston and valve rigidly moved.

Ball Gate Valve

Performed a root cause analysis of the Ball gate valve, which was having vibration lifecycle problems. The analysis of the structural motion reacting to the turbulent fluid identified the problem, and with a small change to the design, fixed the lifecycle problems.

FSI of Blood Flow around a Vein Valve

For a new medical device that is now in the prototype stage, a biotechnology company recently asked for a computational fluid-structure interaction (FSI) analysis for a healthy patient-specific pulmonary arterial tree utilizing the unified continuum and variational multiscale (VMS) formulation.

Reciprocating Engine

Calculated the spatial and time-varying solid body temperature using conjugate heat transfer model in a transient, compressible fluid system. The fluid model was used with a corresponding structural model to identify areas of high stress due to thermal loading.

Reciprocating Compressor

Modeled the transient effects within a reciprocating compressor with compressible methane gas utilizing Ansys Fluent’s moving mesh capabilities.

Industrial Duct

Analyzed the turbulent vortex shedding and the potential fluid-structural interaction caused by the fluid vortices that could be shed of the internal duct structure.




Case Study: Prediction of Valve Closure and Transient Piping

For a US nuclear power plant, Fluid-Structure Interaction (FSI) Consulting services from SimuTech recently conducted a coupled fluid transient and dynamic structural forecast.  Specifically, of a Main Steam Isolation Valve (MSIV) and a Main Steam Check Valve (MSCV).

Fundamentally, the goal of this analysis was to forecast the MSIV and MSCV’s shutting time and speed.  Testing conditions included a variety of custom-client selected environments, including a high energy pipe break. The FSI problem’s outcomes served as the basis for a transient dynamic FEA prediction.

Kinematic Modeling of an MSIV Valve and Actuator

By creating a dynamic or multibody dynamics model of the MSIV valve and actuator, the FSI prediction was carried out (or valve for the MSCV). The transient fluid data from the dynamic model were then linked in Ansys Fluent.  Fluent is a remarkable fluids simulation software designed for computing fluid transients in pipe systems.

Finally, hydrodynamic torque coefficients were generated by performing CFD simulations on the MSIV/MSCV disc.  Placement was strategically arranged at various locations, and then pulled into the final dynamic model.


Case Study: Effect of Flows on Thermal Shock Clearances in a Globe Valve

The effectiveness of valves in a nuclear power plant must be demonstrated under challenging operating circumstances.  Approximately 225°C thermal shocks are one of the certification tests that satisfied this empirical testing.

Here, such shocks are experimentally and numerically investigated on a large globe valve with a nominal diameter of 150 mm. Ansys Maxwell‘s automated testing loop is the internal software site of the experimental campaign.

In pressurized cold and hot water, 10 thermal shocks are carried out one after the other. The tested valve has 40 thermocouples installed evenly along its height.

The body-bonnet flange’s 10 studs are equipped with strain gauges.  In effect, enabling close-monitoring of the evolution of the clamping forces within the flange.  From here, it is carried out a 3D numerical simulation of such a shock in the valve.

A series of multiphysics simulations, including fluid, heat conduction, kinetics, and mechanics, are used to carry out simulations. With multiple contacts, the mechanical simulation represents over 50 different pieces. Pertaining to Fluid-Structure Interaction (FSI) Consulting services, this simulation is presented in two different iterations.  The second of which, accounts for the heat transfer that occurs in clearances.

When it comes to the temperature in the studs, there is a high correlation between modeling and experiment.  Only the second simulation is able to accurately capture the tightening changes.  That is, seen experimentally at the start of cold and hot shocks in terms of clamping forces.

For more information on this case study, contact our engineering experts HERE.


 Fluid-Structure Interaction (FSI) Consulting Services often include: