# Computational Fluid Dynamics

We exist in a world of motion, a world of fluid mechanics. Every movement you make interacts with fluids. Walking down a corridor, air flows around you. Your body heats the air over your head, which rises to the ceiling. A boiling tea kettle introduces water vapor, which disperses and changes the air concentration. A ship turning in a channel may experience water flow around the hull, re-circulation near the propeller shaft, and separation at the rudder blade. Every aspect of change in our world gets shaped by fluid mechanics. Given its pervasive presence, you need the ability to predict and control fluid mechanics. Don’t let the wind and wave control you; work around them.

Computational fluid dynamics (CFD) is a mature technology that allows engineers to understand, predict, and work with fluid mechanics. The flow of wind and waves around buildings and ships can be fiercely complicated, requiring extremely complex mathematics to predict. CFD captures those mathematics in computer programs and allows almost unlimited flexibility. At DMS, we can answer almost any question about fluid flow:

- Wind loads analysis
- CFD motions simulation
- Offshore structure loads
- Seabed sediment scouring
- Calm water resistance study
- Wave slamming forces
- Tank sloshing loads
- Channel flow studies
- HVAC design for open spaces
- Hydrofoil design
- Rudder design
- Roll damping design

CFD requires far more than just software. It demands a dedicated infrastructure, and engineers with a strong background in numerical analysis. DMS engineers have years of experience in cutting edge CFD analysis

- Steady state
- Seakeeping simulation
- Overset meshing
- DFBI simulation
- Large cluster simulations
- and much more . . .

Each project includes extensive supporting QA and mesh independence analysis. We develop a project plan for each CFD analysis to mitigate risk of cost overruns. The techniques used by DMS **put you in control of simulation costs**. We identify the trade-off between simulation cost vs simulation quality, but you make the final choice on the cost of production runs.

Reliable CFD requires certain skills. Without the experience and skill of our engineers, CFD just becomes colorful garbage. At DMS, we *prove* our quality. We often perform validation studies on our own time. **Every project gets a mesh independence study.** Before we even begin your production runs, we can estimate the margin of error in the simulation. This is the science of CFD. The rigors of *proof* to ensure reliability.

Disclaimer: Although DMS strongly believes in justifying CFD analysis through validation studies, our own internal validation efforts are limited based on available resources. We prioritize our studies based on perceived market demand. This means that we may not have validation studies readily available for your particular application or project. DMS works with our clients on a case by case basis to ensure we provide the appropriate level of proof while still maintaining necessary project schedules.

Image Credit: Andreas Kempf

## Want to Learn More?

We are happy to discuss your next project. We can customize each project to meet your exact goals.

We also offer free general project plans to help prepare for your next round of quotes.

At DMS, we are dedicated to your success.

# Relevant Ship Science Articles

## Guts of CFD: Interpolation Equations

The core of all calculus problems require us to consider something infinitely small. Ask a computer to ponder the concept of infinity and watch its circuits fry. If we want to solve the equations of computational fluid dynamics (CFD), we need a way to fake calculus. This impacts the stability, the mesh quality, and the ultimate simulation quality. Enter interpolation equations.

read more## Guts of CFD: Transport Equation

What is the utility of a transport equation? What do they achieve? Transport equations form the fundamental language of computational fluid dynamics (CFD). CFD engineers use them to communicate ideas, program CFD software, and diagnose problems with their simulations. But they only work if you understand the language. Today we explain transport equations and the significance of their terms.

read more## Guts of CFD: Navier Stokes Equations

Navier Stokes Equation. Shrouded in mystery and intimidation. Navier Stokes is essential to CFD, and to all fluid mechanics. This equation defines the basic properties of fluid motion. But there is more to gain from understanding the meaning of the equation rather than memorizing its derivation. Today we review Navier Stokes Equation with a focus on the meaning behind the math.

read more## Practical CFD: General Approach

Just fresh out of college, and the boss assigned your first project for computational fluid dynamics (CFD). You are excited. You can’t wait to begin the challenge. You sit down at your computer, start up the CFD software . . . and freeze like a deer in headlights. How to begin? What to do first? Today we discuss the general workflow for a CFD project and highlight some general modeling advice.

read more## CFD Workflow

What happens behind the curtain when the CFD engineer goes to work? What goes into making a CFD simulation? As a project manager, you need to understand the workflow of a CFD project; this helps you plan the project and track budget expenses. When we understand the workflow, we know the right questions and can anticipate project delays.

read more