Pipe exit

The exit Mach number Mo may not exceed unity Mo = 1 corresponds to choked flow sonic conditions may exist only at the pipe exit. The mass velocity G in the charts is the choked mass flux for an isentropic nozzle given by Eq. (6-118). For a pipe of finite length. 

Before accepting this solution, the Reynolds number should be checked. At the pipe exit, the temperature is given by Eq. (6-120) since the flow is choked. Thus, T[Pg.651]

For return manifolds with K = 1.0 and 4fL/(3D) 1, 5 percent maldistribution is achieved when hole pressure drop is 20 times the pipe exit velocity head. 

VELOCITY AT PIPE EXIT WHEN DISCHARGING CONDENSATE AT SATURATION TEMPERATURES FROM VARIOUS PRESSURES TO ATMOSPHERE AT A RATE OF 100 POUNDS/HR. 

If A2 is very large compared with A, as, for instance, at a pipe exit, then ... 

Every house has some minimum penetration through the slab or foundation walls. The ones always present are water pipe entry and sewer pipe exit. Common additional penetrations are floor drains, sump holes, and air conditioner condensate drains. 

This can be evaluated using the Omega method, if applicable (see Annex 8) or other HEM model (see Annex 4). The Omega method can be used to obtain G and the exit choke pressure, PE for the upstream pipe. An isenthalpic flash calculation can then be performed from the stagnation pressure at the start of the pipe to the choke pressure, PE, in order to evaluate the mass fraction of vapour, x, at the pipe exit. If the flow is not choked, then the term (PE - Pa) becomes zero. 

Step 7 Calculate the pressure loss APA of pipe fittings. There is one fitting loss, the pipe exit into the column. To calculate the exit loss, use Eq. (6.33) for pipe sharp-edge exit ... 

The above results show that the flow is laminar and that the flow will not be fully developed at the exit of the pipe. The program discussed above gives the variation of dimensionless temperature with dimensionless radius at the pipe exit. The program has therefore been run up to a maximum Z value of 0.00004163. This gives the dimensionless temperature variation with dimensionless radius at the exit listed in Table E4.4. The actual radius and temperature are then obtained by recalling that ... 

Although the potential energy provides the flowing fluid with kinetic energy at the pipe entrance, the kinetic energy is later recovered. This indicates that the measured pipe pressure will be lower than the calculated pressure by one velocity head. If the kinetic energy is not recovered at the pipe exit, the exit counts as a loss of one velocity head. Table 3-2 shows how K varies with changes in pipe size. 

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