Whether losses. Minor energy head losses are due to


Whether a fluid is experiencing laminar or transitional fluid
flow can be determined by its Reynolds number, which is discussed below.
However, transitional flow can possess many flow rates and mannerism due its
differing frictional energy whilst flowing therefore with separate equations to
predict its fluid flow behaviour.


A typical piping system involves; various diameter pipes
connected by various fittings/elbows, which route the fluid, valves to control
flow rate, pumps to pressurize the fluid. Fluid flow, especially liquids, are
generally transported in circular pipes as they can endure great pressure variances,
without substantial distortion. The loss of pressure/energy (for example, in
the forms of heat or sound) in a fluid, through a pipe, is due to the required
energy to overcome the viscous or frictional forces exerted by the walls of the
pipe on the moving fluid (Uio.no,
n.d.). Energy losses also occur due to fluid flowing through
fittings (valves, elbows, contractions and expansion). The pressure losses in
pipes are known as head losses, derived from Bernoulli’s equation. Head losses
are categorized into minor and major head losses. Minor energy head losses are
due to the bends and valves present within the system whereas, energy losses
due to the frictional resistance acting against the flow of the fluid, are
defined as major head losses; together equating to the total head loss. (Kabir, 2014)

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 Major head losses are
calculated using the Darcy-Weishbach equation, equation 1:

The dimensionless quantity, the Darcy frictional factor, is
used in the Darcy-Weishbach equation, equation 2. It is used as a description
of the frictional losses in pipe flow (Nuclear Power, n.d.):The friction factor, f is dependent on the flow’s Reynolds
number and on the pipes degree of roughness on the pipe’s inner surface (.  Reynold’s number is dimensionless and is the ratio of the fluids’
inertia force to the fluids viscosity force, and can be found using the
equation 3:

 Reynolds number can be used to describe the behavior of the flow. The
flow can be either laminar or turbulent depending on whether the Reynolds
number is above or below a critical value. The critical Reynolds value for pipe
flow is around 2000. Where above critical value is a turbulent flow and below
is laminar (both flows can be observed when the value is close to the critical
value). Experimental evidence has proven and concluded that the frictional
factor is dependent on the Reynolds number as well as the degree of roughness. As
outlined on the moody chart (Engineeringtoolbox.com, n.d.).


As a rule, the flow is:

Laminar when Reynolds number is <2300. ii)             Turbulent when the reynolds number is 2300