Viscous Flow Scores  






Quiz 0 has been corrected. I gave B+ if you registered and A+ if you registered and enabled email notifications for the Viscous Flow forum.


Quiz 1 is corrected. I took away points if you didn't do the proof I asked you to do in class.. And I also took away points if you didn't indicate clearly where the stresses are located on the fluid element or if some steps are not well explained enough.


Quiz 2 is corrected. I took away points if I found your proofs were not clear enough (A0) or one or more was incomplete (B+ or less). Simply saying $\partial u/\partial y + \partial v/\partial x=0$ for no rotation is not enough: this has to be proven.


Quiz 3 is corrected. I took away one half grade if you didn't take into consideration the body force on the fluid or if you computed this body force wrong. Be careful about the body force acting on the fluid: this has nothing to do with the density or mass of the piston. I also took away a half grade if you didn't calculate well the area on which the shear stress acts.


Quiz 4 is corrected. I took away points for the following reasons: (i) you didn't iterate to find the answer, (ii) you didn't write down the units when needed (writing $100 u_\infty = 10 $ N is wrong, you need to write $100 {\rm Ns/m} u_\infty = 10 $ N), and (iii) you didn't integrate both the laminar and turbulent regions.


Quiz 5 is corrected. I took away a half grade if you didn't indicate clearly how you obtained $e$ from the Moody (using Re$_D$ and $f$). I took away more points if you didn't obtain $f$ from the wall shear stress.


Quiz 6 has been corrected. I took away half a grade if you didn't indicate clearly how you found that the flow in the pipe is turbulent.


SuperQuiz A7A8D1 has been corrected. For the design problem, I took away points if you did some illegal memory usage (you can't do u[N]=u[N2], this is not valid because there is no memory allocated for u[N]), if you didn't impose correctly the symmetry condition, or if you didn't get all the coefficients of the inner nodes correct. Those who didn't get A0 or A+ in the design project are at risk of not getting an A in this course. If you care about getting an A, I recommend to put a bit more time on your design project as a preparation for the final exam.


I finished correcting the final exams. You did great — I'm very happy with your scores. Merry Xmas and Have a nice holiday!



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