pressure head


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pressure head

n
(General Physics) physics a more formal name for head24a
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Request for quotations : selection of a supplier for the manufacture, delivery, installation and commissioning (analogue) of pressure head block-modular water treatment plant crystal - n with a capacity of 6.
Since EMAs and other electronic devices must operate at various altitudes and climate conditions throughout a flight mission, there is a need to develop a variable speed fan with high pressure head and high flow rate that can operate efficiently and reliably over a wide range of operation conditions.
Assuming that pipe diameter (D) increases with the pressure head at the pipe inlet ([H.sub.o]), according to a power-law model (D = C [H.sub.o.sup.p]), and that the head loss (J) decreases as the diameter increases, an equation of head loss for the uniform permanent flow was fitted, in the form of Eq.
The results show that when the radius of the cavern is constant, the pressure head and seepage flow decrease as the distance between the tunnel and the cavern increases.
The variations in pressure head and soil deformation in each layer of the system are simulated to analyze the process of land subsidence along with an analysis of the dividing point that appears in aquitards adjacent to the pumped layer when the hydraulic head in the pumped layer recovers gradually.
where [K.sub.x] (h), [K.sub.y] (h), and [K.sub.z] (h) represent hydraulic conductivity in the x, y and z axis, which are all functions of the pore water pressure head h when unsaturated.
where Se is the degree of saturation; q is the volumetric water content ([cm.sup.3] [cm.sup.-3]); [theta]s is the saturated volumetric water content (cm3 [cm.sup.-3]); [theta]r is the residual volumetric water content (cm3 [cm.sup.-3]); a is an empirical parameter ([cm.sup.-1]) whose inverse is often referred to as the air entry value or bubbling pressure; h is the soil water pressure head (cm); and n is a pore-size distribution parameter affecting the slope of the retention curve.
The primary direct laboratory methods used are the pressure extractor (Klute 1986), which estimates 9(h) from pairs of measured h and [theta] values, and the evaporative method, which calculates K and [theta] (h) from the pressure head response of two tensiometers placed at different depths (Gardner and Miklich 1962).
To avoid size effection of the coarse aggregates, the dimension of the pressure head is chosen as 100 mm which is about 3 times larger than the largest coarse aggregate in the gussasphalt.
whereas the maximum pressure head ([h.sub.LM]) required at the upstream end of the lateral is
In this study, only the seepage law of unsaturated soil in horizontal direction is considered, so the position head is steady along x-direction and the pore water pressure head is variable.
The difference in losses between plain lateral pipes and with sealed emitters were calculated for constant increasing pressure head. Equal lengths locally extruded from four different pipe rolls were selected for diameters i.e.