How Coupled Flow and Structural Models Reduce Development Risks
Increasing efficiency requirements, higher power densities, and shorter development cycles are currently putting greater pressure on the mechanical and plant engineering sectors. At the same time, traditional development and testing methods are increasingly reaching their limits. This is because many problems today no longer arise from individual components, but rather from the interaction of physical effects. Those who still consider fluid flow and structure in isolation often do not discover critical weaknesses until during testing - or at the customer’s site.
In many technical systems, fluid flow and mechanical behavior directly influence one another. Fluid flow generates forces, pressure pulsations, or vibrations that deform or stress components. At the same time, these deformations in turn alter the flow behavior. The risks of unexpected interactions increase significantly, particularly in cases of high power densities, dynamic load conditions, and energy-intensive applications. If these interdependencies are not taken into account early on, they often lead to rework, increased validation efforts, or unplanned iterations in the development process.
“Many development problems do not arise during testing—but much earlier. They simply become apparent too late,” says Dipl.-Ing. (TU) Stefan Merkle, managing partner of Merkle CAE Solutions GmbH. “Coupled simulations help to understand these interactions early on and make development decisions more robust.”
This is particularly relevant, for example, in pumps, valves, heat exchangers, and piping systems. Pressure fluctuations or transient flows can cause resonance, vibrations, or unexpected load conditions in these systems. The importance of such analyses is also growing significantly in plant engineering, energy technology, and hydrogen-based systems. Especially in transient operating conditions, traditional individual analyses are often no longer sufficient.
For example, during the analysis of a housing subjected to fluid flow, coupled CFD and structural mechanics simulations were used to identify critical resonance ranges that would have led to increased vibrations during actual operation. Through targeted design modifications, the stress levels were significantly reduced even before a prototype was built. This significantly minimized development costs and subsequent rework.
Today, modern multiphysics approaches enable the realistic modeling of such interactions—from transient flow patterns and thermal effects to dynamic structural responses. For engineers, this means one thing above all else: a better basis for decision-making in the early stages of development. Critical load cases become apparent, design variants can be evaluated in a targeted manner, and systems can be designed to be more robust before actual prototypes are built.
The integrated analysis of flow and structure is thus evolving from a specialized field into an integral part of modern product development. Companies that validate these interactions digitally at an early stage reduce risks, improve system performance, and lay the groundwork for more efficient development processes in mechanical and plant engineering.
