Wading through the alphabet soup of aerodynamic analysis tools can feel overwhelming, even if you mostly know what you’re looking at.
And if you’re not entirely sure what kind of tool you’re looking for, how can you tell XFOIL from AVL from VSP from all the different flavors of CFD? Much less which one you should use?
Each program has its strengths, as well as notable limitations. Best practices usually call for using a handful of them, because they can complement each other and help you better develop and understand your aircraft design.
Let’s try to clear up some of the haze around aero design tools.
Right off the bat, I will say I’m not 100% the expert on aerodynamic tools. I don’t know of every tool out there, and I definitely haven’t personally used them all.
But I do know how to evaluate a tool and tell you what it’s probably good for. And I can provide guidance on what sort of tools would be best for solving certain engineering problems or plugging knowledge gaps.
So that’s what we’re going to focus on here. And as always, if you want to dig deeper on a certain point, just email me.
There are two main criteria that really differentiate tools from each other and determine how they’re most useful:
Inviscid versus viscous flow: does the simulation include the effects of friction between air molecules? A tool with viscous effects will have some sort of stall prediction, and will include friction drag of whatever you’re analyzing. A tool with inviscid flow will never show any turbulent effects, including stall. In return for that simplicity, inviscid tools are typically much quicker to set up, and compute much faster too.
2D versus 3D analysis: does the tool only analyze 2D profiles, like airfoils? Or does it assume a 3D object and include the associated effects?
I can think of a tool for every combo of just those two criteria alone. And those barely scratch the surface of what makes every analysis tool uniquely suited for a certain problem.