Homework
- 2-25: In transporting liquids, pressures can drop. What happens to a liquid
when its pressure drops? Cavitation is a major safety concern!
- 2-83: Please take the time to relate the drag force to the velocity profile.
WHERE do we evaluate the drag? If two velocity profiles have the same slope at the
wall, but different velocity profiles in the middle, will the drag be the same or different?
- 3-26: What would happen if the piston where free to move further than 3 m? That is, what if
it just kept on going?
- 5-W1: The axial velocity profile for laminar flow in a pipe is given by
u(r) = Umax * (1-r*r/(R*R)) where r is radial position, R is the pipe radius, and Umax is the
maximum velocity. For R=1 m, and Umax=1 m/s, compute the volumetric flow rate. What value do
you get if you assume the velocity is uniform at the average velocity?
- 5-W2: Consider the bucket and hose from problem 5-7. Suppose that a 1.5 inch hole appears in the bottom of the 2 ft high bucket just as it is completely filled and the water is turned off. The velocity of the water through the bottom hole is determined by the equation v^2 = 2*g*H, where H is the height of the water, v is the velocity of water through the hole, and g is the gravitational constant. At what time will the bucket reach a volume of 10 gallons?
- 5-47: See table A-11.
- 5-W3: Please read and comprehend Book examples 5-5 through 5-9 in your text. Just write "did it"
for your homework.
- 6.32: Make sure you can fully do problem 6-32 on your own (you will see this type of problem again.) You need a relative velocity since the cart is moving.
But don't neglect the proper treatment of mdot in addition to cart movement.
- 6.24: This problem requires the calculation of pressure. Since we haven't covered this topic yet, you can assume a pressure at the inlet of 73.92kPa.
- HW 14: Click Here
- HW 18: Click Here
- HW 20: LCDLM Homework - Watch each of the following videos:
- Velocity Trends
- Energy Transitions
- Pressure Trends
- Nonlinear Trends
- Additionally, please complete and submit the worksheet assigned in class.
- Hint: Problems 9-30, 31, 34, and 38 are in the "Continuity Equation" section of the homework.
- 9-34: When you integrate dy/dx = x^2 you get y=x^3/3 + c. If instead we have y=y(x,z) and
the derivative is a partial derivate, the integration results in a function, c=f(z). That is, instead of
a constant of integration, we get a function of integration that is a constant with
respect to the integration variable, in this case c(z). This arises from the process of taking a partial
derivative. Any function that isn't dependent on the variable when are taking the derivative with respect
to goes to zero, and when we integrate a partial derivative, we have to account for that fact by adding
a function with respect to the other variables, rather than a constant alone.
- 9-87: Read and understand Example 9-14, which is very similar to this problem.
(Of course, you knew that, because you did your reading :-)
- HW 26 problem: Click Here
- HW 29: Click Here
- HW 30: Click Here
- Optional CFD Homework: 15.1, 15.2, and 15.16.
Special problem: write the equations used to evaluate the structured mesh of problem 15-3. Assume that the left nodes are 1 in the x direction, and the bottom nodes are 1 in the y direction. The left and right boundary conditions are that the flow is zero, while the boundary conditions for the top and bottom are that the flow is equal to Vf and Vi, respectively.