Flow in Pipes and Channels

Calculate the hydraulic mean diameter of the annular space between a 40 mm and a 50 mm tube. 

The hydraulic mean diameter, dm, is defined as four times the cross-sectional area divided by the wetted perimeter. Equation 3.69 gives the value dm for an annulus of outer radius r and inner radius r, as  

015 m3/s of acetic acid is pumped through a 75 mm diameter horizontal pipe 70 m long. What is the pressure drop in the pipe  

A cylindrical tank, 5 m in diameter, discharges through a mild steel pipe 90 m long and 230 mm diameter connected to the base of the tank. Find the time taken for the water level in the tank to drop from 3 m to 1 m above the bottom. The viscosity of water is 1 mNs/m2. 

If at any time the depth of water in the tank is h and levels 1 and 2 are the liquid levels in the tank and the pipe outlet respectively, then the energy balance equation states that  

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Isothermal Gas Flow in Pipes and Channels Isothermal compressible flow is often encountered in long transport lines, where there is sufficient heat transfer to maintain constant temperature. Velocities and Mach numbers are usually small, yet compressibihty effects are important when the total pressure drop is a large fraction of the absolute pressure. For an ideal gas with p = pM. JKT, integration of the differential form of the momentum or mechanical energy balance equations, assuming a constant fric tion factor/over a length L of a channel of constant cross section and hydraulic diameter D, yields,... 

Other Flow Straightening Deviees Other devices designed to produce uniform velocity or reduce swirl, sometimes with reduced pressure drop, are available. These include both commercial devices of proprietaiy design and devices discussed in the hterature. For pipeline flows, see the references under flow inverters and static mixing elements previously discussed in the Tncompressible Flow in Pipes and Channels subsection. For large area changes, as at the... 

For nonisothermal flow of liquids across tube bundles, the fric tion factor is increased if the liquid is being cooled and decreased if the liquid is being heated. The factors previously given for nonisotherm flow of liquids in pipes ( Tncompressible Flow in Pipes and Channels ) should be used. 

The universal turbulent velocity profile near the pipe wall presented in the preceding subsection Tncompressible Flow in Pipes and Channels may be developed using the Prandtl mixing length approximation for the eddy viscosity,... 

Streamline Flow in pipes and channels of regular geometry... 

Isothermal Gas Flow in Pipes and Channels Isothermal compressible flow is often encountered in long transport lines, where there is sufficient heat transfer to maintain constant temperature. Velocities and Mach numbers are usually small, yet compressibility... 

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