Pressure analysis in EPANET
The Hazen-Williams formul was used, because it is the most widely used head loss formula. It cannot be used for liquids other than water and was originally developed for turbulent flow only. 1
Where V= mean velocity of flow in pipe (m/s)
R= hydraulic radius (mean depth) (m)
S= hydraulic gradient
C= coefficient of roughness of pipe
Table 3. 1 lists expressions for the resistance Coefficient and values for the flow exponent for each of the formulas
Table 3. 1 pipe head loss formulas for full flow
Formula Resistance Coefficient
(A) Flow Exponent
(B)
Hazen-Williams 4.727 C-1.852d-4.d871L 1.852
Notes: C = Hazen-Williams roughness coefficient d = pipe diameter (ft)
L = pipe length (ft)
Source: EPANET Multi-Species Extension User’s manual
Table 3. 2 Roughness coefficient
Material Hazen- Williams coefficient (C)
Cast iron 130-140
Concrete or concrete lined 120-140
Galvanized iron 120
Plastic 140-150
Steel 140-150
Vitrified clay 110
Source: (EPANET, 2002)
3.3.2 Water CAD
Water CAD software was used to see the nodal and link features of the water supply and distribution network for scheme-1 and scheme-2 of Woldiya town.
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The hydraulic Network of the water supply Distribution system and the town water supply design has been analyzed for the present situation. During data analysis, the nodal pressure and pipe link velocity has been determined to identify high or low pressure zones areas of the node/junction where the pressure is higher or lower than the design criteria of system network. These findings of hydraulic Network of the water supply Distribution system of the town bring the suggestion and recommendations that will help to improve the water supply system of Woldiya
...lk about projects such as these two,we must bear in mind that there are relatively great chances for the government to atleast have awareness of the underlying practices and situation. If we use the alternatives, it will incur cost but it will let go of the sacrifices and compromises poverty stricken nations have to pay. On the stakeholders i.e. the general masses it will be beneficial as they will be paid for their work in legal framework and will be provided water products in the market (Me, 2014).
"As a rule of thumb R< ~2000 laminar flow and R> ~3000 turbulent flow" Anything in between 2000 and 3000 is unstable and may go back and forth between laminar and turbulent flow.
The study also noted that the problems of water supply and wastewater disposal are inextricably linked. Providing public water system service to self-supplied households without sewer connections greatly increases domestic
Figure 1: mx is the mass for each rower x (1-4) and coxswain (c), M is the mass of the boat, and Fx (x=1- 4) is the force exerted by the stroke and Fdrag is the resistive force of the water.
Water shortage is a growing problem for most countries in the world. For China, which has 20% of world’s population and only 7% of available water resources, this problem may become catastrophic (Hofstedt 2010, 72). Therefore some actions and measures should be performed to avoid or at least to weaken future water crisis in China. In this work the following three solutions will be proposed and analyzed in terms of efficiency and applicability: water usage efficiency improvement; adopting the local agencies on controlling water resources; reasonable water pricing.
The shear viscosity is a transport coefficient for momentum in inhomogeneous flows. This transport coefficient, which is widely used to describe both plasmas and fluids, relates two hydrodynamic quantities: shear stress and shear rate. The shear stress Pxy is the off-diagonal element of a pressure tensor, and the shear rate γ is the transverse gradient of the flow velocity u. For a flow in the y direction,
29 Mar 2011. http://www.dlr.de/100 Jahre/en/desktopdefault.aspx/tabid- 2565/4432_read-7449/>. Prandtl, Ludwig. A. Essentials of Fluid Dynamics.
An observations table was made to record the initial volume and temperature of NaOH (aq) and HCl (aq); the table also included sections to record temperatures, at 5 second intervals with a final 30 second plateau, for each of the 3 trials.
...stem. Authors found this topic as an important subject of critical flow conditions in water resources systems analysis and design. Importance of engineering implementation and maintenance is considered.
...e has been the role of the aqueduct since the Roman engineers developed it. “… aqueducts enabled human civilization to grow and spread on a much larger scale than would have been possible without such technologies, and they are just as vital today as they were at the dawn of civilization,” (Aqueducts 1). Aqueducts will continue as important roles in the transportation of fresh water to modern cities for the foreseeable future. As technologies and materials advance, aqueducts will adapt to these changes. However, the concept of supplying water to a city in need will not change. “Water acquisition and distribution systems are unquestionably among the most important technologies that humans possess. Although water systems are typically ignored and taken for granted, they enable myriads of other technologies and activities within human societies,” (Aqueducts 1).
Smith, F. L. and Harvey, A. H. (2007) Avoid common pitfalls when using Henry's law. Chemical Engineering Progress, 103(9), pp. 33-39.
where p is the density of the fluid (in runner’s case: air); v is the velocity of the runner; A is the cross-sectional area perpendicular to the runner’s velocity; and D is the dimensionless quantity called the drag coefficient.
Water connects to people live through out the history, and it is the source for lot of Megacities develop in the ancient time until
[5] Ratliff, Richard L; Beckstead, Stephen M; Hanks, Steven H; Quality Progress; Jun 1999; Pg. 31