Not enjoying thermo, will I enjoy fluid mechanics?

[Gauss M.D.]

I'm pondering courses for the autumn and I'm at a bit of a crossroad. Doing an intro thermodynamics class right now which involves all the stuff I don't really enjoy - measurements, looking stuff up in tables, memorization, etc. Very non-theoretical. It feels like an AP chemistry class basically.

The impression I've gotten from fluid mechanics and especially CFD is that it involves programming, theory, vector calculus, PDE:s etc, i.e. stuff that I very much enjoy. But thermo is a prerequisite. Can I expect more of the same if I enroll in higher level fluid mechanics courses?

 

[caldweab]

Are you a physics major? I'm an engineering major and my thermodynamics class deals with all kinds of interesting applications of thermodynamics, and it doesn't just involve looking stuff up in charts and measurements. I took fluid dynamics as well, fluid dynamics has a lot in common with thermodynamics but it also has a lot in common with heat transfer. There's more differential equations and partial differential equations. All in all fluid dynamics was a pretty interesting course

 

[Gauss M.D.]

Applied math/physics. There's a lot of applications touched upon, but there's an utter lack of exciting theory. It's basically an AP high school class.

 

[caldweab]

Applications and real world applications are more interesting in my opinion and what matters when you start working. But I'm guessing theory is why you went the applied math and physics route instead of engineering

 

[cjl]

Fluid dynamics can involve a fair amount of themodynamics, yes, but it can also be quite different. It certainly doesn't have to involve a lot of looking stuff up in tables (though tables can be very helpful for supersonic flow, since it can get irritating applying the same equations 20 times to get a result...).

 

[jbrussell93]

Doing an intro thermodynamics class right now which involves all the stuff I don't really enjoy - measurements, looking stuff up in tables, memorization, etc. Very non-theoretical. It feels like an AP chemistry class basically.

Is this a thermo class offered by the physics department or engineering? Can I ask what book you are using?

My engineering friends seem to be having the same experience as far as feeling like "an AP chemistry class". I am a physics major taking "thermodynamics", but it is really statistical mechanics. We are basically building up all of the macroscopic laws of thermodynamics by looking at the microscopic and applying statistics. In fact, the first chapter of the book is statistics prerequisites and it is quite theoretical (Fundamentals of Statistical and Thermal Physics by Reif). I can also say that I have not needed to use any tables.

As far as fluid dynamics, I think it also depends on which department is teaching it. At my school, both the engineering and mathematics department teach a fluids class. You can image how much they differ...

 

[AlephZero]

As far as fluid dynamics, I think it also depends on which department is teaching it. At my school, both the engineering and mathematics department teach a fluids class. You can image how much they differ...

That's not surprising. Leaving aside what you can simulate with computer software (that sub-topic is much too big to be covered in a first fluids course, and being introduced to it by writing your own toy finite difference programs to solve 1D problems won't teach you much about the current state of the art in any case), fluid mechanics can broadly be split in two. There are practical real-world problems that can best be solved by qualitative understanding of what happens, plus semi-empirical correlations (e.g. water flow in networks of open channels) , and pretty mathematics that has very little to do with most real life fluid flows (e.g. solving 2-D flows of incompressible inviscid fluids by conformal mapping techniques).

You can probably guess which department teaches which half of the subject

(There should be a joke about modeling a fluid as a stampeding herd of rigid frictionless spherical cows hiding somewhere around here - oh, wait, isn't that what the ideal gas equations do? Now, where did I put my steam tables...)

 

[Gauss M.D.]

It's the engineering dept, although there are CFD courses higher up that I've been sniffing on a little bit. I'm kind of getting the impression that all of it is either applicable and thoroughly uninteresting, or interesting and thoroughly unapplicable.

Reading a little bit elsewhere has given me the impression that it's the same when actually making a career out of CFD and general computational mechanics as well - just sitting around solving routine problems with proprietary software.

 

[moogull]

It's not very far into the school semester yet, from what I remember, engineering thermo was very elementary in the beginning but gets hard (and useful) pretty quickly. It might be worthwhile to look into what the second semester of thermo covers as well

 

[caldweab]

I don't like the sentiment people have that engineering courses are elementary. What? You cannot do any problems or be a competent engineer without understanding concepts. Anybody can plug numbers into equations but do you really understand the equation and what information you can get from it? In the real world can you apply those concepts to solve real problems? I don't know about other schools but my teacher actually gave quizzes on deriving the important equations and explaining how they are used and when they are valid. I had the same teacher for heat transfer, fluid dynamics, fundamentals of nuclear engineering and I'll have him for reactor engineering next semester. He gave us problems to solve but be mostly focused on concepts and actual understanding of the subjects. My strength of materials, reactor theory and thermodynamics class were taught the same way except by a different teacher. I learned a lot and when I did take engineering problem solving ( Matlab, maple) we had to apply concepts learned in other courses to solve problems. Maybe it depends on the school though I guess, but we actually get a good helping of concepts, theory, and real world applications.