Flow of fluid past a cylinder (A) laminar and (B) turbulent.

**CALCULATION OF THE PRESSURE DROP IN A PIPE DUE TO FRICTION**

If
the volumetric flow rate of a liquid of density ρ and viscosity η through a pipe of
diameter d is Q, the derivation of the mean velocity, *u*, from the flow rate and pipe area completes the data required for
calculating Re.

*FIGURE 2.11** **Flow of fluid past a cylinder
(A) laminar and (B) turbulent.*

If the pipe roughness factor
is known, the equivalent value of R/ρu^{2} can be determined from
Figure 2.10, and the shear stress at the pipe wall can be calculated. The total
frictional force opposing motion is the product of R and the surface area of
the pipe, πdl, where l is the
length of the pipe. If the unknown pressure drop across the pipe is DP, the force driving through the
pipe is ΔP · πd^{2}/4. Equating pressure
force and frictional force gives

Division
by ρ*g* gives the pressure loss as a friction head. This form is
used in equations (2.7) and (2.8).

Related Topics

Contact Us,
Privacy Policy,
Terms and Compliant,
DMCA Policy and Compliant

TH 2019 - 2024 pharmacy180.com; Developed by Therithal info.