Basic Principles
Piping – Moody Friction Factor
The factor of proportionality in the previous equations is called the Moody friction factor and is determined from the Moody resistance diagram shown in Figure 8-1. The friction factor is sometimes expressed in terms of the Fanning friction factor, which is one-fourth of the Moody friction factor. In some references the Moody friction factor is [...]
25Sep2009 | admin | Comments Off | ContinuedPiping – Darcy’s Equation
This equation, which is also sometimes called the Weisbach equation or the Darcy-Weisbach equation, states that the friction head loss between two points in a completely filled, circular cross section pipe is
proportional to the velocity head and the length of pipe and inversely proportional to the pipe diameter. This can be written:
Equations 8-5 and 8-6 [...]
25Sep2009 | admin | Comments Off | ContinuedPiping – Bernoulli’s Theorem
It is customary to express the energy contained in a fluid in terms of the potential energy contained in an equivalent height or “head” of a column of the fluid. Using this convention, Bernoulli’s theorem breaks
down the total energy at a point in terms of
1. The head due to its elevation above an arbitrary [...]
Piping – Flow Regimes
Flow regimes describe the nature of fluid flow. There are two basic flow regimes for flow of a single-phase fluid: laminar flow and turbulent flow. Laminar flow is characterized by little mixing of the flowing fluid and a parabolic velocity profile. Turbulent flow involves complete mixing of the fluid and a more uniform velocity profile. [...]
25Sep2009 | admin | Comments Off | ContinuedPiping – Reynolds Number
The Reynolds number is a dimensionless parameter that relates the ratio of inertial forces to viscous forces. It can be expressed by the following general equation:
The Reynolds number can be expressed in more convenient terms. For liquids, the equation becomes:
25Sep2009 | admin | Comments Off | Continued