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  1. Aurora09

    thermo question

    hey all, just a quick question on thermo properties: does enthalpy, internal energy, specific value and entropy of a material all change with composition?
  2. Aurora09

    fluid mechanics - pressure drop in a pipe

    Hey guys, I hope you can help me out on understanding the concept of pressure drops in pipes.  For the pressure drop equation P2 - P1 = pgHf (where Hf is frictional head loss), does this only apply to pipes when elevations are the same, z1 = z2?  Also, if the pipe is sloped at an angle, then...
  3. Aurora09

    hydrographs?

    Thank you so much!! And your drawing looks perfect to me :D
  4. Aurora09

    hydrographs?

    Hi @Jbone27 PE. Thanks for taking your time to reply! I should have been more specific in my original post as to what part of the solution confused me, but anyways I was stumped on why they subtracted 15 hrs - 12 hrs = 3 hr. I would have taken the Q value at t = 12 hr. I guess I'm not...
  5. Aurora09

    hydrographs?

    @Jbone27 PEhey! sorry for the late response but here is the problem: A 6 hr storm rains on a 25 mi2 (65 km2) drainage watershed. Records from a stream gaging station draining the watershed are shown. (a) Construct the unit hydrograph for the 6 hr storm. (b) Find the runoff rate at t = 15 hr...
  6. Aurora09

    hydrographs?

    Does anyone have a better explanation for the hydrograph problem in Example 20.4, Part B from the CERM? I'm not understanding their solution so if someone can please explain that'd be great!
  7. Aurora09

    Hydraulic jump question in open channel flow

    Hello, I am stuck on the following problem: Water flows in a rectangular channel with depth of 0.40 m, width of 1.0 m and velocity of 6 m/s. Calculate the alternate depth.  Here is how the solution manual solved it: E = y1 + v2/2g Plugging in the values above will give you 2.235 m for the...
  8. Aurora09

    hydraulic elements graph problem

    @Acedeala Thanks for pointing me in the right direction! That's exactly what I ended up doing! I used mannings equation to solve for Qfull (substituting with the Afull value) and then used the ratio of the given flowrate (Q) to Qfull to get the value from the graph for d/D.  I also just looked...
  9. Aurora09

    hydraulic elements graph problem

    I'm stuck on solving the problem below: A 72 inch diameter vitrified sewer pipe (n=0.014) is laid on a slope of 0.00025 and carries wastewater at a flow of 50 ft^3/s. What is the depth of flow? I think I have to somehow follow the mannings n graph line from the Hydraulics elements graph for...
  10. Aurora09

    Relative roughness of a pipe?

    Thank you - I went ahead and resolved the equation! My answer is still different than the link provided. However, I did notice a mistake in their calculation for K2. Even when I tried correcting their equations, the answer was still different than the way I set it up  Anyways, do you think my...
  11. Aurora09

    Relative roughness of a pipe?

    @Slay the P.E. Here is a picture of my work below: (Note: Top reservoir is labeled A and the lower one is labeled B).  I wasn't sure if Vb should be 0 so I ended up combing it with the same V in the Darcy head loss equation. My assumption might be wrong here. Also, should I also be adding...
  12. Aurora09

    Relative roughness of a pipe?

    I don't want to create too many topics so I hope its okay to post my additional questions here lol. but anyways, can someone assist me on pipes in parallel (please see question #7 in the following link: http://bu.edu.eg/portal/uploads/Engineering, Shoubra/Civil...
  13. Aurora09

    Relative roughness of a pipe?

    Thanks for your responses! @Audi driver, P.E. @Slay the P.E.
  14. Aurora09

    Relative roughness of a pipe?

    When determining the roughness, e, of a pipe - which value do we use from the range provided in the table? For example, the values of e for cast iron range from 0.0006 - 0.003 (im looking at the table on the moody diagram from the PE handbook). Do I take the average of the highest and lowest...
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