Search results
Results from the WOW.Com Content Network
Darcy–Weisbach equation. In fluid dynamics, the Darcy–Weisbach equation is an empirical equation that relates the head loss, or pressure loss, due to friction along a given length of pipe to the average velocity of the fluid flow for an incompressible fluid. The equation is named after Henry Darcy and Julius Weisbach.
Pressure head is a component of hydraulic head, in which it is combined with elevation head. When considering dynamic (flowing) systems, there is a third term needed: velocity head. Thus, the three terms of velocity head, elevation head, and pressure head appear in the head equation derived from the Bernoulli equation for incompressible fluids:
Hydraulic head or piezometric head is a specific measurement of liquid pressure above a vertical datum. [1][2] It is usually measured as a liquid surface elevation, expressed in units of length, at the entrance (or bottom) of a piezometer. In an aquifer, it can be calculated from the depth to water in a piezometric well (a specialized water ...
The hydrostatic pressure p is defined as =, with p 0 some reference pressure, or when rearranged as head: =. The term p / ρg is also called the pressure head, expressed as a length measurement. It represents the internal energy of the fluid due to the pressure exerted on the container.
Hazen–Williams equation. The Hazen–Williams equation is an empirical relationship which relates the flow of water in a pipe with the physical properties of the pipe and the pressure drop caused by friction. It is used in the design of water pipe systems [1] such as fire sprinkler systems, [2] water supply networks, and irrigation systems.
In fluid dynamics, total dynamic head (TDH) is the work to be done by a pump, per unit weight, per unit volume of fluid. TDH is expressed as the total equivalent height that a fluid is to be pumped, taking into account friction losses in the pipe. where: Static lift is the difference in elevation between the suction point and the discharge point.
Darcy's law is an equation that describes the flow of a fluid through a porous medium. The law was formulated by Henry Darcy based on results of experiments [1] on the flow of water through beds of sand, forming the basis of hydrogeology, a branch of earth sciences. It is analogous to Ohm's law in electrostatics, linearly relating the volume ...
Euler's pump equation. Based on Eq. (1.13), Euler developed the equation for the pressure head created by an impeller: (1) (2) Y th : theoretical specific supply; H t : theoretical head pressure; g: gravitational acceleration. For the case of a Pelton turbine the static component of the head is zero, hence the equation reduces to: