10 Non-Round ConduitsIf the conduit is not a pipe it is a square, triangle or any other shapes we replace the diameter by the hydraulic diameter.𝐷ℎ= 4∗𝐶𝑟𝑜𝑠𝑠 𝐴𝑟𝑒𝑎 𝑊𝑒𝑡𝑡𝑒𝑑 𝑝𝑒𝑟𝑖𝑚𝑒𝑡𝑒𝑟For Example and rectangular tube with L(Length) and W(wide) the hydraulic diameter will be:-𝐷ℎ= 4∗𝐿∗𝑊 2(𝐿+𝑊) = 2∗𝐿∗𝑊 (𝐿+𝑤)
11 ExampleAir (T = 20°C and p = 101 kPa absolute) flows at a rate of 2.5 m3/s in a horizontal, commercial steel, HVAC duct. (Note that HVAC is an acronym for heating, ventilating, and air conditioning.) What is the pressure drop in inches of water per 50 m of duct?
17 ExampleA pump is to be used to transfer crude oil (! = 2 × 10!4 lbf-s/ft2, 1 = 0*86) from the lower tank to the upper tank at a flow rate of 100 gpm. The loss coefficient for the check valve is 5.0. The loss coefficients for the elbow and the inlet are0.9 and 0.5, respectively. The 2-in. pipe is made from commercial steel (e = 0*002in.) and is 40 ft long. The elevation distance between the liquid surfaces in the tanks is 10 ft. The pump efficiency is 80%. Find the power required to operate the pump.
24 ExampleA piping system consists of parallel pipes as shown in the following diagram. One pipe has an internal diameter of 0.5 m and is 1000 m long. The other pipe has an internal diameter of 1 m and is 1500 m long. Both pipes are made of cast iron(e = 0.26 mm). The pipes are transporting water at 20C (ρ= 1000 kg/m3, v= 10^-6 m2/s). The total flow rate is 4 m3/s. Find the flow rate in each pipeand the pressure drop in the system. There is no elevation change. Neglect minor losses.