?H = 4fLV^{2} / 2dg (European SI Based)

?H = head loss (m)

f = friction factor

L = length of pipe (m)

V = mean flow velocity (m/s)

d = hydraulic diameter (m)

d_{circular pipe} = 4 x cross sectional area / wetted perimeter

(The wetted perimeter is the perimeter of the cross sectional area that is “wet”, i.e in contact with the pipe)

g = gravitational constant = 9.81 (m/s²)

The friction factor in the D’Arcy formula needs to be estimated. The friction factor depends on the Reynolds number (Re) of the flowing liquid and the relative roughness (k/d) of the inside of the pipe.

The Reynolds number may be described as the ratio of inertial forces to viscous forces and, consequently, it quantifies the relative importance of these two types of forces for given flow conditions

Re = ? V d / ? = inertia forces / viscous forces

? = density of fluid (kg/m^{3})

? = absolute or dynamic viscosity (Ns/m^{2})

V = mean velocity (m/s)

d = hydraulic diameter (m)

d_{circular pipe} = 4 x cross sectional area / wetted perimeter

The transition between laminar and turbulent flow in circular pipes is generally accepted to be at about Re = 2300. Avoid any pipe configuration within the range 2000 to 3000 to ensure the flow is either fully laminar or fully turbulent.

For liquids with high Reynolds number you can use the Colebrooke & White formula for turbulent flow: –

1 / f = -4log_{10} (( k / 3.7d ) + ( 1.255 / Re f)) (Re >3000)

k = the average height of the roughness projections

I’ve chosen a 3.0 meter diameter cast iron pipe.

As you try narrower pipes, the friction head rises sharply.

Kind Regards

M

Pls supply me with some guides in lifting water from ground surface to a mountain top.Pipes and pumps are to be used

Thanks

Hellow – you have asked bit of a vague question. Please be more specific in your needs.

I expect a pump manufcaturer catalogue will answer most of your questions.

If going very large distance upwards, you will need multiple pumping stations.

Hi.. i just want to know how many hp is needed to convert a 20Hp mechanically pump to a motor driven pump? thanks

jhen Said:

Hi.. i just want to know how many hp is needed to convert a 20Hp mechanically driven pump to a motor driven pump? thanks.

Well, if the mechanicaly driven pump, has 20 hp on it, then you need a 20 HP motor. Which is 20 x 0.746 KW.

Hi guys..Im gonna pump 18m3/h from a depth of 15m (submerged in seawater). The opening in the suction pump end is 95cm2 and thereon the water should be pumped through an 100m hose and onboard a vessel. The outlet of the water will be 2 m above surface area. Does anyone know what pump this might be? Thanks a lot in advance!

Hellow,

Please help me: I need to know motor water pump I found to bay with H=30 and Q=50m3 could do me a job on 20m height and 200m lenght of pipes

Put numbers into the spread sheet given

Easy – look up wind turbine manufacturers catalogues and see the diameter they use for wind pumps.

You need to say if your pump is mechanically driven, in which case you need a multiblade rotor, or electrically driven in which case you need a two blade rotor.

Assuming a multi blade make sure you are looking at a multiblade manufacturers direct drive pump.

Hi, I need to choose a pump for emptying a sewage tank at about 0.1m3/s and it would only need to be lifted around 20m. Any ideas on how to find the perfect one? Thanks.

Just phone any pump supplier or look in their catalogue. You will need to choose a suitable pump for sewage as otherwise it is likely to block with rags etc. When you have round one, put the details here as a comment please.

Actually that is some pump – 20 m head, so it will need to be submersible – you won’t be able to suck it out.

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DEARS

I AM FROM THE DESERT OF LIBYA ,WISH TO KNOW THE METHOD REQUIRED FOR INTEGRATES THE WIND TURBINE INTO DESERTIFICATION PROGRAMS AS DOCTORATE THESES

BEST REGARDS

YOUSEF

Hi use the Tag Cloud, and Category Search and the search box to find the articles on ADRECS and Sea Water Greenhouse

Best

Dave Andrews

ok yoin dgls avwb