Thermodynamics Grinds In Galway

Hi, I actually never did!

It's funny I'd get a reply now, I'm still failing it! I've got a last chance saloon repeat at 09:30 tomorrow morning!

I know of a fella that might be able to help who is an NUIG Graduate, but I'm not sure if he's up for giving grinds, I'm actually getting in contact with him today.

I'll ask him if he'd be interested, and I'll get back to you later on.

Hi Kevin!

I actually do have one specific question that's driving me nuts!

"A piston cylinder device containing water"

I'm given the mass (m) of the water, the pressure (P1) at initial state, the initial temperature (T1), and the CSA (A) of the piston face.

"Heat is now transferred to the water, causing part of it to evapourate and expand. When the Volume reaches (V2), the piston reaches a linear spring, whose constant is (k). More heat is transferred to the water until the piston rises (x)cm more.

Determine the final pressure and temperature."


The way I tackled it, I let P2=P1 as the piston was expanding freely before it met the spring.

To find P3; P0=F/A
Where F = kx
(P0 is the extra pressure caused by the resistance of the spring added to the value for P1)

P3 = P0+P1

Then I hit a wall when it comes to finding the Temperature T3... Not sure what I can do about it... Can I Use Tsat @ P3 on the Steam Tables? or do I need to do something more complicated to find the Temperature?

(Note: the mass is probably given for part b) of the question, which is a P-V diagram, and I'm assuming I use the mass solely for finding the Volume V1 by dividing the mass by the density of water.)

No such luck as far as finding grinds goes i'm afraid. I passed my exam now, by the very skin of my teeth!

I used a book called "Thermodynamics: An Engineering Approach" by Yunus A. Cengel & Michael Boles. (I bought the book on Amazon, but I think it's possible to find an eBook of it through other means if you know what I mean)

The book is massive, and it would take a LONG time to read, but it is split into sections that are pretty much all possible Questions that can come up in a Thermodynamics exam. I didnt read a single chapter, I skipped to the example questions in the back of each chapter, and I looked through past exam papers to see what types of questions come up most of the time. Many of the examples are almost word for word the exact same questions as were on my exam, but with slight variances in nature and figures.

In short: see if you can find out off a lecturer what book they use for the notes they give, it may even be part of the recommended reading that is briefed at the beginning of the semester, then if it has examples in it, never mind reading anything, just use probability to roughly determine what questions may come up in the exam, then study the hell out of the method of them using the examples you have in the book.

One other thing I did that helped me grasp the concept of some of the basics before delving into the examples was khan academy.

https://www.khanacademy.org/science/physics/thermodynamics/v/thermodynamics--part-1

Watch all the videos on that page that are applicable to the content of your module (probably most of them) and pause and redo things that go over your head, or you don't quite understand until it makes some form of sense. Your man in the vids explains everything pretty well, and it definitely helps establish a bit more understanding of what is going on in the example questions. Each vide is like 10 mins long, and you can get through the lot in about 4 hours if your dedicated enough, although its probably best to do them bit by bit. I took notes while watching them like I was in a lecture just to help it go in more.

One more thing that I found to be fairly useful for example questions regarding adiabatic turbines especially is www.learnthermo.com, but it seems to be crashing firefox at the minute, so I dunno how good that site is to you. The lecturer that made that site is really helpful and if you email him he might get back to you with assistance (but don't just mail him a load of sample questions and ak him to do them out for you because he won't)

That's about it, I can do no more. Couldnt find anybody to tutor Thermodynamics in Galway, the place is a dried up wasteland in the way of extra curricular help for Engineering.

Hope some of the stuff I mentioned can help you out!

Good luck!!