posted 1 years ago

1) The head (the vertical drop between your intake point and the turbine location for power generation)

2) Flow speed (how much water comes down the pipe)

3) Pipeline (penstock) length and diameter

posted 1 years ago

posted 1 years ago

You are to then determine the proper pipe size for each section of pipe based solely on flow rate considerations. When selecting pipe sizes, ensure that the velocity does not exceed 6ft/s. Use type L copper pipe. Provide a sketch and show the results in boxes on the sketch. All pipe is interior to the building.

posted 1 years ago

Instead of making the theoretical calculations, you are to use the equivalent length information provided in Appendix C on page C-11. In addition, use the charts on pages C-13 & -14 for copper pipe and the chart on C-16 for the steel pipe. Complete the following table to determine:

1. The head loss in each section (ft. w.c.).

2. The total system head loss and indicate if it is ABD or CBD (ft. w.c.).

posted 1 years ago

Part Ci. Write the Manning equation for friction head loss, hf= ...ii. For iron pipes, what is a typical, mid range value for Manning's n, with units?iii. For constant n, if the discharge is doubled, by what factor does the head loss increase?

Problem 2: Comparing Three Equations for Head Loss

Compare three equations for friction head loss in pipes, assuming constant friction factors.Recall the slope of the energy grade line (EGL) is S= høL.

Part Ai. Write the Darcy-Weisbach equation for friction head loss, hf= ...ii. For iron pipes, what is a typical, midrange value for the friction coefficient, 2?iii. For constant 2, if the discharge is doubled, by what factor does the head loss increase?

posted 1 years ago

A circular pipeline stretches 202 miles from an initial elevation of 510 ft to a final elevation of230 ft. The pipe (D = 3.0 ft) is made of concrete (A= 0.0030 ft). The open channel flow is steadyand uniform such that the pipe is half full. The fluid is water at 50° F.

Part A Sketch a cross-section of the pipe flowing half full, then calculate its hydraulic radius, Rh [ft].

Part B Calculate the discharge, Q [ft/s].

posted 1 years ago

Explain why iteration is required to solve the following classes of pipe flow problems using theDarcy-Weisbach equation (<20 words each part):

Part A Given pipe diameter D and friction head loss hf, find discharge Q.

Part B Given discharge Q and friction head loss hf, find required pipe diameter D.

posted 1 years ago

A culvert transmits 0.45 m/s of water from the pond at left (surface elevation 123.0 m) to the pond at right (surface elevation 122.0 m). L =25 m and D = 50 cm. The flow is steady anduniform, and the pipe is completely full.

Part A Use Bernoulli's equation to calculate the friction head loss. [m]

Part C Calculate Darcy-Weisbach's friction factor 2.

Part B What is the average velocity? [m/s]

Part D Calculate Hazen-Williams's roughness coefficient CHw.

Part E Calculate Manning's n with units.

posted 1 years ago

This semester we worked through several versions of the pipe flow problem sketched above, in which a 3.0 ft diameter pipe is used to convey water from reservoir A (surface elevation 80 ft) to reservoir D (surface elevation 90 ft). In week 14, we considered a specific example with a cast iron pipe (A = 0.00085 ft), flow rate of Q = 40 ft/s, and average velocity of V = 5.66 ft/s. For these conditions, the friction factor was 2= 0.015 and the pump added 85 ft of head. Assume the water temperature is always 60°F.

Part A Assuming the pump is 75% efficient and electricity costs 10¢/kW hr, how much will it cost to run this pumpfor a year? Hint, 1 kW hr = (1000 watts)(1 hr) =(1000 J/s)(3600 s) = 3.6x10° J.

Part BNow let us assume we need to double the discharge to Q=80 ft’/s, but unlike the example in week 13, we are not going to make the false assumption that the friction factor 1 is constant. You may, however, assume that the roughness height A is constant. We will consider three options:

Option #1: Build a parallel system with the same pipe and pump, with a flow rate of Q= 40 ft’/sin each system. What is the annual electricity cost?

Option #2: Use the original pipe but double the velocity. What is the annual electricity cost?

Part C Briefly comment on the pros and cons of options 1-3 (<30 words).

Option #3: Build a new pipe with diameter of 50.9 in. The cross-sectional area of this pipe is twice that of a 36 in pipe, so the velocity will be V= 5.66 ft/s for a discharge of Q= 80 ft’/s.What is the annual electricity cost?

posted 1 years ago