u/AllAboutCFD

Vorticity at the back of the estateback model

CFD postprocessing is storytelling!

When we run CFD, the solver gives us numbers, contours, and vectors.

But those plots alone rarely convince anyone.

At the end of the day, CFD doesn’t sell itself.

The story you tell through your postprocessing does.

When I look back at my early CFD projects, I realize something important.

I thought running the solver was the hardest part.

Mesh generation, turbulence models, BCs, I obsessed over them.

When the results came in, I proudly shared contour plots and vector fields.

And the response was silence.

Why? Because nobody else in the room could see what I was seeing.

To them, it was just a rainbow of colors.

To me, it was flow separation, pressure recovery, and efficiency losses.

That’s when I understood, post processing is not plotting. It’s storytelling.

The job of a CFD engineer is not just to simulate. It’s to translate.

To take terabytes of raw data and weave them into a story that drives action.

Anyone can generate plots.

But only an engineer who can tell the story can create impact.

Source: SimScale [Vorticity at the back of the estateback DrivAer model]

Video

u/AllAboutCFD — 14 hours ago

Jet breaking the sound barrier

A US Navy fighter jet creating “shockwave lines” as it approaches close to the speed of sound.

Actually, the airplane is going slightly less than the speed of sound.

but as the air passes over various parts of the wings and fuselage, it can accelerate to supersonic speeds.

As this happens, the air will be compressed or expanded and those changes in pressure will change how light is refracted or bent as it passes through.

The visible effect is those ‘shockwave’ lines, or sometimes a cone-shaped cloud that envelops part of the aircraft if the air is humid enough.

Physics seen in reality. How beautiful this photo is.

Photo shot by Camden Thrasher.

u/AllAboutCFD — 15 hours ago

Fluid Dynamics Governing Equations! Which one is your favorite?

Fluid dynamics looks complex… it is just one equation at its core!

➡️ Navier–Stokes Equations
The most general equation that governs how fluids move.

➡️ Euler Equations
High speed fluid motion when we ignore viscosity (no friction effects).

➡️ Stokes Equations
Very slow flow where inertia is negligible and viscous effects dominate.

➡️ Hydrostatic Equation
Pressure variation in a fluid that is completely at rest under gravity.

Based on dominant physics, these are simplified forms of Navier-Stokes.

u/AllAboutCFD — 1 day ago

Which method did you start your CFD journey with?

Different numerical methods solving same fluid & heat flow physics.

All of these methods aim to solve the same governing equations (mass, momentum, and energy conservation) but from very different perspectives:

FDM: approximates derivatives directly on structured grids using Taylor Series.

FVM: enforces conservation locally over control volumes (industry favorite).

FEM: uses variational formulation & shape functions (strong in solid–fluid coupling).

LBM: mesoscopic approach using particle distribution functions & Boltzmann equation.

SPH: Mesh free Lagrangian, particle-based method for highly deforming flows.

The physics doesn’t change but the mathematics and discretization philosophy do.

As CFD engineers, understanding why a method works is far more important than just knowing how to run a solver.

u/AllAboutCFD — 1 day ago