Fundamentals of Fluid Mechanics B Questions and Answers  


This will probably work in this case but is dangerous in the general case. The correct way is to start with the strain rates in the tables and obtain the shear stresses from the strain rates. Explain how to do that, and list the assumptions.




Whether you use the friction factor in the tables or not, you should reach the same answer. Also, your answer is definitely not correct. I see at least three fundamental mistakes in your logic.




When solving part (a) you can simply state that $dP/dx$ is a constant for fullydeveloped flow. Then, you can obtain $P=P(x,y)$. But subsequently, you'll need to demonstrate why this is.




No, there are no other assumptions. These strain rates can be used for any fluid. Also, the same applies with the strain rates in cylindrical and spherical coordinates in the tables. The strain rates can be used in the general case.




Let me see if I can find them.. If I do, I'll post them soon.





$\pi$ 