In
fluid dynamics
In physics and engineering, fluid dynamics is a subdiscipline of fluid mechanics that describes the flow of fluids— liquids and gases. It has several subdisciplines, including ''aerodynamics'' (the study of air and other gases in motion) an ...
, the wave method (WM), or wave characteristic method (WCM), is a
model
A model is an informative representation of an object, person or system. The term originally denoted the Plan_(drawing), plans of a building in late 16th-century English, and derived via French and Italian ultimately from Latin ''modulus'', a mea ...
describing unsteady flow of fluids in
conduit
Conduit may refer to:
Engineering systems
* Conduit (fluid conveyance), a pipe suitable for carrying either open-channel or pressurized liquids
* Electrical conduit, a protective cover, tube or piping system for electric cables
* Conduit curre ...
s (pipes).
Details of model
The wave method is based on the physically accurate concept that
transient
ECHELON, originally a secret government code name, is a surveillance program ( signals intelligence/SIGINT collection and analysis network) operated by the five signatory states to the UKUSA Security Agreement:Given the 5 dialects that ...
pipe flow
In fluid mechanics, pipe flow is a type of liquid flow within a closed conduit, such as a pipe or tube. The other type of flow within a conduit is open channel flow.
These two types of flow are similar in many ways, but differ in one important ...
occurs as a result of
pressure waves generated and propagated from a disturbance in the pipe system (valve closure, pump trip, etc.) This method was developed and first described by Don J. Wood in 1966.
A pressure wave, which represents a rapid pressure and associated flow change, travels at sonic velocity for the liquid pipe medium, and the wave is partially transmitted and reflected at all discontinuities in the pipe system (pipe junctions, pumps, open or closed ends, surge tanks, etc.) A pressure wave can also be modified by pipe wall resistance. This description is one that closely represents the actual mechanism of transient pipe flow.
Advantages
The WM has the very significant advantage that computations need be made only at nodes in the piping system. Other techniques such as the
method of characteristics
In mathematics, the method of characteristics is a technique for solving partial differential equations. Typically, it applies to first-order equations, although more generally the method of characteristics is valid for any hyperbolic partial d ...
(MOC) require calculations at equally spaced interior points in a pipeline. This requirement can easily increase the number of calculations by a factor of 10 or more. However, virtually identical solutions are obtained by the WM and the MOC.
See also
*
EPANET
EPANET (Environmental Protection Agency Network Evaluation Tool) is a public domain, water distribution system modeling software package developed by the United States Environmental Protection Agency's (EPA) Water Supply and Water Resources Divisi ...
References
*
{{refend
External links
Journal of Applied Fluid TransientsInnovyze Surge Products
Fluid dynamics
Hydraulic engineering