Capturing real-life fluid-structure interactions
In a simplified simulation, fluid would move through solid structures without imposing any deformation of the topology. Realistically, however, the fluid pressure and shear stress calculated in the fluid simulation cause the solids to deform. Thus, it is important to capture the forces and interactions between the fluid and solid for realistic simulation results.
CONVERGE CFD software allows you to easily model rigid body fluid-structure interaction (FSI). In addition, CONVERGE supports extensions to rigid body structures, including beam deformation and impulse-based contact models. CONVERGE automatically generates the mesh at each time-step and then adapts that mesh to the object’s motion, which can be prescribed a priori or calculated during the simulation based on fluid forces. This feature can be useful, for example, when simulating spring valves, turbine blades, compressor plate valves, store separation, or reed valves.
The nature of an FSI simulation is that the forces imposed by the fluid may deform the object in ways that you cannot anticipate. In CONVERGE, Adaptive Mesh Refinement increases mesh resolution in the areas that require higher resolution as the FSI object deforms. This allows for the optimal use of computational cells by placing cells where they are needed, when they are needed.
Complex interactions within the flow field
The robust FSI capability in CONVERGE has several other useful features. You can specify multiple constraints and multiple degrees of freedom for an FSI object. This way, you can configure an FSI object with prescribed motion that will also be affected by the forces generated during the fluid-structure interaction.
Additionally, CONVERGE now has a contact model that is capable of detecting and properly handling interaction with walls and between objects.