head loss

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head loss

[′hed ‚lȯs]
(fluid mechanics)
The drop in the sum of pressure head, velocity head, and potential head between two points along the path of a flowing fluid, due to causes such as fluid friction.

pressure drop

The decrease in fluid pressure between two ends of a duct or pipeline, between two points in a system, across valves and fittings, etc., due to frictional losses; in a water-piping system a drop in fluid pressure also occurs between two points as a result of the difference in elevation between the two points.
References in periodicals archive ?
The 335 MW expansion adds a second powerhouse, immediately downstream of the Waneta Dam on the Pend-d'Oreille River, that shares the existing hydraulic head and generates clean, renewable, cost effective power from water that would otherwise be spilled.
It was assumed here that the lowest rate of fall in hydraulic head that could be reliably measured in the field (taking into account measurement error, small changes in surface water level over time, change in water temperature, etc.
When a well is pump in a confined aquifer, the declining hydraulic head in the vicinity of the well enables the pressurized water to expand slightly, adding a small volume of additional water.
The dewatering process, by pumping water from the surrounding groundwater body, imposes stresses on the system, which change the distribution of hydraulic head values.
These data along with ground elevation were used in the computation of the hydraulic head.
These valves are also used in controlling the required hydraulic head.
Therefore, the aquifer permeability and transmissivity was enhanced in the hydraulic head highs.
The official said a boost reservoir would also be built in sector D-11 against pumped supplies from Shah Allah Ditta that would cater for supplies to the topographically elevated sectors of F-10 and 11 and G-10 and 11 with sufficient leftover hydraulic head to allow for activation of overhead reservoirs in sectors G-10/2.
The basic scheme of this structure is depicted in figure 1a where: z--is the drainage norm, h--is the hydraulic head, [K.
Medium to large scale bakers and confectioners will appreciate the new hydraulic head raising and lowering mechanism and bowl locking system, which secures the bowl tightly in position for increased stability and safety when in operation.