CHE 4410 – J. J. Biernacki
This web blog is CHE 4410 (Chemical Engineering Capstone Design I) course. Please use it to post helpful information regarding the course materials or projects you might be working on. Also, consider using it as a form of support group for the course, post questions, respond to questions that others have and help each other to learn.
I hope you find this site to be useful. Let’s see how it goes.
J. J. Biernacki
Professor, Chemical Engineering
September 17th, 2015 at 8:42 pm
Where does those two equations from the acetonitrile code come from ?
p2=(150+5)*144
p1=p2+2.144*(L/100)
And how they could be useful in our case ?
September 18th, 2015 at 3:29 pm
p2 in our problem will be the delivery pressure of the methanol or oil. In our case, p2=atmospheric pressure. For the acrylonitrile problem it was 150+5 lbf/in^2.
The second equation for p1 in our case will be similar to that for acrylonitril, p1=p2+2*L/100+10 and then correct for units as you like. There will be 2 psi/100 foot of pipe + 10 psi for the valve. This about this so that you understand why the equations are what they are.
JJB.
September 19th, 2015 at 4:49 pm
I’m a little confused with the friction factor equations. For laminar flow we are using f= 64/Re which is the Darcy friction factor equation but for turbulent flow we are using 1/sqrt(f)= -4*log(XXX) which is the fanning friction factor equation. I know f (darcy) is 4 times f (fanning) so shouldn’t we be consistent with the friction factor equations we use or does it matter?
September 20th, 2015 at 1:30 pm
We used f=16/Re as a fanning factor and we get a very close answer to the 1/√f = -4×log(ε/D/3.7 + 1.256/Re×√f)
September 20th, 2015 at 1:58 pm
^
^
^
For the laminar flow
October 11th, 2015 at 9:09 am
I am having some problems with MathCad. I searched the error and it will say a variable is undefined but it clearly is defined right above the equations with the exact same notation. I’ve even tried changing variable names but I get same error in the end. Any suggestions?
October 11th, 2015 at 6:02 pm
Harley, It is very difficult to say what the problem might be. The error message you receive is not specific to a particular problem even though it sounds at though it is. If you stop by sometime, or send the code to me, I’ll take a look at it.