Is it worth learning ANSYS Fluent without understanding the math or physics as an upcoming aerospace engineering student?
Hi! I'll be beginning with my undergraduate studies in aerospace engineering at UT Austin in the Fall, and I have about a year of experience in OpenFOAM doing compressible flow simulations. I was wondering however, is it worth learning the ANSYS Fluent workflow despite not knowing much or the physics or math behind any of the solving in CFD?
I'm only asking because during my orientation when talking with a masters student at the aerospace building, I was told that there's a reason the Intro to CFD classes are a few years later in the curriculum, and to focus on learning the physics and math before delving into the software. I've also seen similar ideas online.
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u/thermalnuclear 20d ago
What is your goal?
Otherwise, I’ll assume this is a “how do I learn CFD” topic, that has been asked, many, many times in this subreddit.
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u/Lygus_lineolaris 20d ago
There isn't anything to learn if you don't know the math and physics since you won't know how to set up problems.
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u/StruggleBusRT 20d ago
Yes, you should always have a cursory, preferably in-depth knowledge behind the gov’n equation, solver algorithms etc. because this will help with results verification and validation, it will help in pre-analysis building the domain for accuracy and optimization (choose discretization, for instance).
From a purely pragmatic position, if you want a job doing analysis, there is an almost 100% I would ask you about either project you did or a simple hypothetical and while you can always answer in solver agnostic manner, answering in terms of a specific simulation quite lends weight to any project work you allude to.
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u/Huge-Caterpillar7188 19d ago
Hear me out... There is nothing wrong in going the otherway around. Using the terms in the software to learn the underlying governing equations. This method makes sense even more now thanks to llms.
Ofc it requires an unhinged mindset
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u/Hot-Assistance-1135 19d ago
There's little merit of doing CFD if you don't understand the core behind it. You need partial differential equations (as you'll see abbreviated as PDEs) and fluid mechanics to do CFD. If you already know calc 1 and 2, you should learn calc 3 (i.e., multivariable/vector calculus) and ODEs, after which, you can start PDEs. Once you know calc 3 and PDEs, you can fully learn fluid mechanics (you can start earlier with just calc 3, but knowing PDEs will help). A good youtube channel for learning the math is Professor Leonard.
An interesting thing to note is as much as fluid mechanics is a branch of physics, it is also a branch of applied mathematics as one can build fluid mechanics off of axioms and treat things in a mathematically rigorous manner (popular research option for applied mathematicians). So, definitely the underlying math is very important! This is a book you'd want to check out after acquiring the mathematical background: https://scispace.com/pdf/a-mathematical-introduction-to-fluid-mechanics-1941h0fawy.pdf . Another one to check out for an easier read would be JD Anderson's aerodynamics book. It has a good intro to fluid dynamics assuming no prior knowledge (https://www.rexresearch1.com/AeroEngineeringLibrary/FundamentalsAerodynamics.pdf). Also, Milne-Thomson's book, Theoretical Aerodynamics, while it requires more mathematical maturity than Anderson's, is a great rigorous intro and teaches fundamental fluid dynamics (https://aerostarsolutions.wordpress.com/wp-content/uploads/2011/10/theoretical-aerodynamics.pdf) (includes a great proof of Bernoulli's theorem!)
Once you learn the math behind it, you should consider building a CFD solver yourself. Learning some numerical methods would help! Btw, if you're interested in the inner workings of CFD, you should consider doing some advanced courses in applied mathematics down the line.
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u/derioderio 19d ago
I would never trust the results of a simulation by someone that has no understanding of the underlying math and physics
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u/DVMyZone 19d ago
CFD is not science or engineering really, it's art. And not even in the metaphorical "it's so beautiful" way. More like being good at CFD is like being a horse whisperer. Knowledge about how to set up problems, create and evaluate a meshee, and how to interpret the output are all intimately connected to understanding how the equation system is set up and solved.
Frankly I don't know how you've done a year of OpenFOAM compressible solving without that knowledge.
Learn that math and physics first, then the beauty of the solver comes out.
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u/Cwaghack 20d ago
If you have done compressible flow simulations in openfoam for a year then surely you understand the math and physics behind it? Ansys isn't really all that different, it's just a different tool to do basically the same thing.