# What is Computational Fluid Dynamics (CFD) and Why You Need It

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Computational Fluid Dynamics (CFD) is a branch of fluid mechanics that models the flow of fluids (such as liquids, gasses, and plasmas) using computers.

It enables engineers to simulate and analyze fluid-related problems like how air flows over an aircraft wing as it travels at hypersonic speed, how to build the most efficient gas turbine, and how to reduce the fuel consumption of an F1 race car by improving aerodynamics.

The rapid and relatively inexpensive results obtained from CFD calculations help engineers in diverse fields–from environmental engineering to aerospace–design better products faster. By working on simulations instead of physical prototypes, they can reduce costs and make design improvements as early as possible.

In this article, we’ll explore Computational Fluid Dynamics (CFD) clearly and straightforwardly. We’ll discuss its practical applications, benefits, and a few challenges along the way. By the end, you’ll have a solid understanding of CFD and know if this powerful technology could benefit your business.

## What is Computational Fluid Dynamics?

Computational Fluid Dynamics is a way to model the turbulent flow patterns of fluids and heat transfer using advanced algorithms, such as the finite volume method, governing equations, and computers. Historically, engineers designing a new product had to conduct physical tests using prototypes. But thanks to CFD and its ability to predict real-world flow physics, much of this testing can be carried out “virtually.” Engineers can land on optimal designs faster with less expense.

CFD modeling tools use mathematical models and numerical analysis methods to predict fluid motion. The most common CFD solutions are based on the Navier-Stokes (N-S) equations, which consider factors like flow velocity, pressure, and viscosity to provide a detailed picture of how fluids move and interact with their surroundings under specific boundary conditions.

### The Importance of Meshing

“Meshing” is essential in Computational Fluid Dynamics (CFD) for simplifying fluid flow analysis. It involves dividing the studied area into smaller cells, creating a mesh. This CFD model approach allows engineers to focus on solving fluid flow equations for individual cells instead of the entire object, making simulations more manageable for computers.

Mesh quality and resolution impact accuracy. Finer meshes provide more detailed results but demand more computational power and computational resources.

### The Importance of Convergence

“Convergence” in Computational Fluid Dynamics (CFD) is the process of finding a stable and accurate solution to a fluid flow problem with iterative calculations. In simple terms, it’s like solving a jigsaw puzzle or chipping away at a block of wood to make a sculpture : you keep adjusting the pieces until they fit together perfectly or chisel away until you’re satisfied with the sculpture’s final form.

Convergence is the point at which the computer’s calculations stop changing, and we can be confident that we’ve found a reliable solution. Just like an artist knows when their sculpture no longer needs more refining, a CFD software  analyst knows they’re done when the computer’s calculations have converged.

### A Brief History

The basis of Computational Fluid Dynamics (CFD) originated with the Navier-Stokes equations, developed between 1882 and 1850. Progress accelerated from the Stokes equations in the 1960s with more powerful computers and advances from scientists like Hess and Smith , leading to 3D simulations and widespread computational methods used across industries.

### Real-Wold Applications: CFD in Action

Computational Fluid Dynamics (CFD) is a large and growing field with broad applications in multiple industries. It’s now a vital step in the design of various machinery, tools, and components.

Here is a snapshot of how engineers are leveraging CFD simulation software to reduce development costs and improve product quality:

• Gas Turbine Design : CFD is used to increase gas turbine efficiency, reduce fuel burn by up to 15% , and comply with environmental regulations where necessary.
• Hypersonic Speed Simulation : When aircraft travel above Mach 1, fluids start to flow and behave strangely. CFD can capture the complex and unpredictable phenomena that occur.
• Modeling of Submarines : CFD can predict how changes in the contour of the hull, sail, or propulsion arrangement of submarines will affect maneuvering and speed-power performance.
• HVAC Mechanical Engineering : CFD can maximize thermal comfort from air conditioning systems, fans, and blowers in residential and commercial buildings.
• Battery Simulation for EVs : CFD analysis of battery module airflow can optimize cell packing for EV range.
• Oil and Gas Industry : CFD can simulate fluid flow in oil and gas pipelines and determine how solid particles cause erosion.
• Environmental Engineering : CFD can forecast water flow and air pollution dispersion, helping minimize the fallout from oil spills and other disasters.
• Turbulence Modeling : CFD can simulate a turbulence model to improve the stability of helicopters in flight.

### What Are the Benefits of CFD?

#### Accelerated Decision-Making

CFD enables engineers to make faster and better decisions, improving their designs’ quality, durability, safety, and performance. This speed leads to increased productivity and more efficient use of engineering resources.

#### Reduce Development Time

By utilizing CFD software , engineers can significantly reduce development time, minimizing the need for time-consuming physical testing and trial-and-error methods.

#### Cost & Labor Reduction

CFD helps reduce costs and labor by automating workflows, minimizing the need for physical prototypes and methods, and freeing up engineering resources.

#### Testing Complex Scenarios

CFD allows engineers to test complex scenarios that would be impossible to recreate in the real world, ensuring the highest level of accuracy for precision products.

#### Sustainable Testing & Meeting Regulations

CFD simulation offers a more sustainable approach to testing, enabling engineers to rapidly evaluate trade-offs and meet stringent environmental regulations without producing waste and emissions.

#### Accelerated Time-to-Market

With faster insights and decision-making, CFD helps engineers accelerate the time-to-market for their products, giving them a competitive edge.

#### Enhanced Innovation & Design Flexibility

CFD simulation enables engineers to explore wide-ranging design possibilities, fostering innovation and creativity.

#### Improved Collaboration & Knowledge Sharing

CFD simulations can be shared and visualized easily, enhancing collaboration among team members and facilitating better communication of complex engineering concepts. This leads to better-informed decision-making and a more cohesive team.

CFD tools are scalable and adaptable to a wide range of industries and applications, making them a versatile solution for engineering challenges. This adaptability allows organizations to leverage CFD across multiple projects, problems, and scales, maximizing its benefits and overall return on investment.

## Challenges and Limitations of CFD

Despite the clear advantages of CFD (it’s ubiquitous across all industries for a good reason!), it’s essential to recognize the challenges that can arise during its implementation. The requirement for a high level of expertise in fluid simulation mechanics, numerical simulation methods, and computer science makes implementing CFD a daunting task for some organizations.

Partnering with KETIV, and our CFD consulting service, where we specialize in manufacturing innovation, and digital transformation, can help your business optimize and accelerate CFD implementation. Our deep industry experience in process integration, automation, fluid simulation, and data management will provide you with the necessary tools, support, and best practices you need to overcome any issues.

## Conclusion

Computational Fluid Dynamics (CFD) is a digital technology that allows engineers to model fluid-structure interaction, flow problems, and optimize designs. Widely adopted across various industries, including aerospace, automotive, oil and gas, and environmental engineering, CFD helps engineers design better products faster, for less, making manufacturers more agile, competitive, and profitable.