Computational fluid dynamics simulations (CFD) are very useful. Here are some applications:
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Aircraft and UAV design and performance.
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Heat transfer analysis for heating, cooling, and electronics.
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Sizing ductwork and blower motors for HVAC systems
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Wind loads on structures
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Motor vehicle design
These are a few examples. Many more applications exist. The key is ensuring your simulations provide an accurate representation of the design. Experience in both analytical predictions and real-world testing helps a lot. After years in engineering, I’ve predicted how fluids affect many objects and vehicles. I’ve participated in wind tunnel tests, analyzed data, and written reports. This experience supports the shift from predictions to real results. I’ve reviewed many test reports. These include wind tunnel tests, flight tests, aero-ballistic tests, and more.
Sanity Checks
By “sanity checks,” I mean performing quick hand calculations on a design or change. This uses classic aerodynamic methods alongside finite element analysis (FEA). It helps confirm or reject the analysis’s validity. CFD has many settings that must be correct for accurate results. Color contour plots and visible streamlines look great, but be careful not to rely on them too much.
A More Simplified Approach
A gradual approach can be helpful. Start with a simplified model, then add design complexity. Most CFD analyses are nonlinear, making timely solutions tricky. A stepped approach can highlight where the program struggles to find solutions. Small changes in flow conditions, mesh density, and turbulence models can lead to unexpected results.
Interpolation and Extrapolation
You can use FEA for interpolation or extrapolation. Here’s a quick overview:
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Interpolation means estimating design changes that place new data between two existing points.
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Extrapolation involves extending a graph to find data beyond its current range.
This task estimates trends rather than absolute values. Combining previously acquired data with CFD analysis methods works well.
Using advanced computer methods for CFD, along with tests and hand calculations, can help save money.
Norman Neher
Analytical Engineering Services, inc
Elko New Market, MN
www.aesmn.org