Computational Fluid Dynamics

CAD-embedded CFD Simulation

Computational Fluid Dynamics (CFD) refers to the numerical method of simulating steady and unsteady fluid motion using computational methods and hardware.

CFD simulation in computer-aided design (CAD) for designers to analyst.

shorten development timelines

CFD Simulation in the CAD interface
Automated meshing for CAD-embedded CFD
CFD using CAD geometry without simplification
Pre-processing and time spent preparing CAD for CFD is eliminated or minimized
Frontload CFD simulation

What is CFD Simulation?

There are three main methods of predicting the behavior of fluids and their interaction with the surrounding environment – experimental, analytical, and numerical. Computational Fluid Dynamics (CFD) refers to the numerical method of simulating steady and unsteady fluid motion using computational methods and hardware.

CFD simulation is a well-established methodology often used to replace or supplement experimental and analytical methods to aid the engineering design and analysis of everyday products. Compared to prototyping and experiments, CFD simulations are:

Less expensive to run
Faster to complete
Can tackle phenomena that are difficult for experiments
Give in-depth understanding of the physics involved
Lend themselves easily to exploring multiple designs and scenarios

How does CFD Simulation work?

A CFD simulation involves the use of the fundamental laws of mechanics, governing equations of fluid dynamics and modeling to mathematically formulate a physical problem. Once formulated, computing resources use numerical methods to solve the equations using CFD software to obtain approximate solutions for the physical properties involved.

CFD simulations are based on the Navier-Stokes equations used to describe the temperature, pressure, velocity, and density of a moving fluid. The accuracy of CFD simulations depend on the fidelity of the model, approximations and assumptions used, experimental validation and the computing resources available. It is important to characterize the uncertainties and errors in the CFD simulation to use it as an effective tool in design and analysis.

Steps in the CFD Simulation Process

No matter the software used, all CFD simulations follow these generalized steps:

Preprocessing: The preprocessing stage involves creating the geometry of interest in 2D/3D, preparing the geometry for CFD simulation and breaking up the domain into small volumes/cells in a process referred to as meshing or grid generation. Flow condition, fluid properties, laws of physics, initial and boundary conditions and other variables are translated into mathematical models and equations in this stage.
Solving: Here, the CFD simulation software begins iteratively solving the discretized equations using the CFD solver. This step can require significant time or computing resources. For complex simulations, more enterprises are turning to cloud computing as a cost-effective solution to this issue.
Postprocessing: Once the solving is complete, the next step is to analyze and visualize the results of the simulation qualitatively and quantitatively using reports, monitors, plots, 2D/3D images and animations. Verification and validation of the results is also included in this stage.

CFD simulation in the CAD interface

Fully CAD-embedded CFD simulation enables design engineers to analysts to conduct fluid flow simulation and evaluate heat transfer in the CAD design environment, with an intuitive interface and using CAD geometry directly. This eliminates the time overhead of CAD data translation, eliminates geometry simplification or preparation for CFD steps, and allows engineers to conduct multiple design studies and evaluate results. Design engineers therefore can focus on how modifications to geometry or operating boundary conditions influence performance. As simulation results are available earlier in development, informed decisions can be made.

Automated meshing for CAD-embedded CFD

Intelligent pre-processing and automation can help design engineers to analysts be more productive with a CAD-embedded CFD tool. Working in the CAD environment, fast automatic leak detection, methods to quickly seal geometry and automatic fluid volume detection are desirable examples of intelligent automation that can speed up any CFD simulation process. Automated meshing technology designed to work directly with CAD geometry and handle complex or variable quality geometry without the need to simplify CAD models is recognized as a key to faster, accurate CFD for the design environment. There is proven value in stable, robust cartesian immersed boundary gridding methods whereby automatic mesh refinement is based on geometry features, and can be combined with solution adaptive refinement for regions of higher flow and thermal gradients.

When meshing is possible to automate and reduce from days to hours or from hours to minutes, then it is providing a true step change for shorter CFD analysis compared to typical CFD software. Intelligent automation coupled with innovative automated meshing technology and ease of use allows design engineers and non-specialists to reliably conduct CFD analyses early in the design process. When combined with localized meshing controls and advanced options, CAD-embedded CFD also provides a fast and efficient alternative approach for experienced analysts to tackle a wide range of typical CFD problems.

Applications of CFD

CFD simulation software is used in a wide range of engineering applications whenever there is a need to understand or predict fluid flow and heat transfer and the resulting effect on the design of a product or system. In industrial product design, CFD simulation has progressed now to simulating the Multiphysics behavior in complex geometries enabling companies to fully understand and optimize their product design virtually before building a prototype.

Industries, where CFD simulation is widely used, include:

Aerospace
Automotive
Chemical
Consumer products
Marine (ship design, propulsion systems, engine design)
Electronics
Energy (Nuclear, Oil & Gas, Power generation)
Building services
Life sciences
Turbomachinery
Sports
Other general applications involving fluid flow and heat transfer

Find out how others are successfully using Simcenter FLOEFD

Simcenter FLOEFD in combination with Creo

"The usage of Simcenter FLOEFD in combination with Creo has halved the lead time of the design process and ensured that one third less was spent on building physical prototypes."

Wouter Leus, Advanced R&D Expert Xeikon

Reduce development time with Simcenter FLOEFD

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Predict transition to turbulence in flat plate channel flow.

"I appreciate the straightforward and fast simulations with Simcenter FLOEFD. We at APEX-Research successfully used Simcenter FLOEFD for many years and now we have increased confidence in its results through our own modeling experiment."

Dr.-ING. Jens Kitzhofer, APEX-Research B.V.