Good question. It comes down to making an educated guess, then seeing if it matches up at the end. If it doesn't, then you should make a better guess and continue with your trial and error until the guessed temperature and the calculated temperature are (relatively) close. I'm sorry that this isn't a better answer!
Thanks for your question! If you had assumed a different Ts, the temperature at which you were looking up your properties would have changed. This could be OK, if you solved the problem and found a Ts that was still relatively close to your guess. However, if the Ts calculated at the end of the problem was very far from the temperature you guessed, you should guess a new Ts, look up new properties, and re-solve. Hope this helps!
Yes, it says in the book that I've read that in order for you to use the formula Nu=.332Pr^⅓Re^½ which is valid only for Laminar Flow on Flat Plates: (Re < 5×10⁵) and (Pr>.6)
If the fin is L x W, then q' = q/W. In this case you assumed a square fin L x L. Thanks for posting this video!
How do you determine which dimension to use for q'?
What values did you need to know in order to find Kf, Pr, and kinematic viscosity on the table? Did you only need Tfilm, velocity, and length?
How do you just guess Ts… what’s the logical reason?
So how do you guess the Ts?
Good question. It comes down to making an educated guess, then seeing if it matches up at the end. If it doesn't, then you should make a better guess and continue with your trial and error until the guessed temperature and the calculated temperature are (relatively) close. I'm sorry that this isn't a better answer!
LearnChemE Does that mean I sometimes may need to make a lot of(maybe hundreds of) guesses until the guess and the result match?
It shouldn't because each guess should be closer to the correct result.
And you can always set up a computer program to find the answer as well.
will I still get the answer if I had assumed a different "Ts" ?
Thanks for your question! If you had assumed a different Ts, the temperature at which you were looking up your properties would have changed. This could be OK, if you solved the problem and found a Ts that was still relatively close to your guess. However, if the Ts calculated at the end of the problem was very far from the temperature you guessed, you should guess a new Ts, look up new properties, and re-solve. Hope this helps!
Is there no other go without guessing Ts????
how u get the correlation
There are standard formulas which have been calculated after deriving them from first principles
Re=19950 is laminar? Really?
Yes it is..
@@ayushdhasmana3509 no it’s not
Yes, it says in the book that I've read that in order for you to use the formula Nu=.332Pr^⅓Re^½ which is valid only for Laminar Flow on Flat Plates:
(Re < 5×10⁵) and (Pr>.6)
@@maryjoymorzowhat is your reference book for that?
@@kuiper6732 Heat and Mass Transfer by Yunus A. Çengel