How a Finite Element Analysis Complements Your Flow Simulation
When prototyping or testing systems that involve the use of fluids or gasses, engineers use both computational fluid dynamics (CFD) and finite element analysis (FEA) to analyze the relationship between a fluid or gas and the structure it is flowing through. In a previous article, we discussed how engineers use CFD to analyze how liquids or gasses will respond to forces exerted upon them; for example, engineers can use CFD to examine turbulence in fluid as it flows, force exerted on equipment by gasses, possibilities of changes in state, and more.
But CFD is only one part of a more robust analysis that can determine equipment design or investigate system problems. While CFD allows for a detailed analysis of fluid flows, engineers use FEA to determine the effects of those fluid flows on the piece of equipment being analyzed and how that piece of equipment will hold up over time.
What FEA Can Tell Us
Finite element analysis is typically part of a multi-disciplined engineering approach. FEA can be used to test custom machine design, assess vibrations, analyze the effects of vortex shedding, conduct failure investigations, and evaluate individual components or complex pressure vessel design. Though FEA can certainly be used as part of a design process to virtually prototype equipment before it is built, Matrix engineers more often use FEA to analyze problems with existing systems and determine a piece of equipment’s fitness for service.
The first step in using FEA is determining when it is necessary. In some situations, some simple calculations can provide the analysis needed; in other cases, the problem requires the high level of detail FEA provides. FEA’s level of detail can help determine if a piece of equipment is able to withstand whatever forces are being exerted upon it, whether it be heat, pressure, vibrations, or more. Ultimately, finite element analysis can guide engineers in determining if a piece of equipment should continue in its use, be modified, or be taken out of service.
What Situations Call for FEA?
Using FEA to test equipment viability is a specialty of Matrix engineers. Company leaders will often call upon Matrix to validate their existing equipment design and find (and fix) weaknesses if they exist.
Here are some examples of problems that can be solved using FEA:
Analyze cavitation in a control valve
Engineers use CFD to evaluate the vibration and flow of liquid as a result of cavitation. Once they use this process to get the frequency of the force on the back of the pipe, they can then map that force into a solid model in FEA and determine if it puts excessive stress on the pipe and connected components. (Another name for this process is fluid structure interaction, or FSI.)
Evaluate performance in extreme pressure and temperatures
Imagine a jet engine test stand is being designed. High pressure and temperature air flows through the pipe out of the jet engine, and this pipe must contain the pressure from the jet engine or it will fail catastrophically. FEA is needed to ensure the flows modeled inside the pipe (with CFD) will not destroy the pipe or its components when the pressure and temperature are elevated to extreme levels during testing.
Prevent equipment from being damaged by environmental conditions
In a recent case, Matrix engineers were called upon to examine high stacks (attached to a boiler) that had been damaged in the wind. Throughout their use, vortex shedding causes an alternating change in air pressure on side of the stacks which made the stack sway back and forth to an excessive degree, cracking the concrete base. Matrix engineers used FEA to examine solutions to the problem and fix the existing design.
These are just a few of the ways engineers use FEA in combination with CFD to analyze and provide solutions for complex situations.
Rely on the Experts
Finite element analysis is a useful simulation tool that can improve system performance and save time and money in the long run. However, it’s also a complicated tool that requires knowledgeable and experienced engineers to perform well. This is where Matrix’s multi-discipline engineering services come in. FEA is certainly useful during the prototyping phase, but FEA can also be particularly helpful in validating existing designs—a specialization of our engineers. Our clients continually rely on Matrix to provide safe and efficient new designs utilizing CFD and/or FEA. In addition to our original designs, clients rely on Matrix to properly analyze and fix problems that arise in their existing systems so they can get back on track.
Matrix Technologies is one of the largest independent process design, industrial automation engineering, and manufacturing operations management companies in North America. To learn more about our multi-disciplined engineering solutions or finite element analysis, contact Chris Mach, PE, Senior Consultant (Team Leader), Process Solutions Department.
© Matrix Technologies, Inc.
Tags: Chris Mach, PE and Brandon Grodi, PE / Analysis / Cavitation / CFD / Computational Fluid Dynamics / FEA / Finite Element Analysis / Flow-Induced Vibration / Fluid Structure Interaction / FSI / Heat Transfer / Multidiscipline Engineering / Vibration / Vortex Shedding / Analysis and Design / Ansys Mechanical
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