Re: Physics/hydraulics of water and barrel
 

"Mike Romain" <romainm@sympatico.ca> wrote in message
news:41A4C55B.4F42B023@sympatico.ca...
> Jeepers wrote:
> >
> > In article <30jsckF3182ubU1@uni-berlin.de>,
> > "Ray Drouillard" <cosmicpam2@comcast.net> wrote:
> >
> > > you will want to have a valve to keep the water from running out
through the pump and
> > > back into the barrel that's in the truck.
> > > Ray Drouillard
> >
> > Same for the top fill hole hose? Won't want to run backwards?
> >
> > I'm gonna use the top fill hole anyway so I don't have to disconnect the
> > drain hose from the cabin.
> >
> > I lost the physics argument, but I had the right idea.
> >
>
> No way you lost the physics argument!
>
> You asked which is easier? This means less 'work'.
>
> If you had a real reservoir there and had 'say' for easy numbers 100 psi
> coming out the bottom pipe, then you 'first' have to build up 100 psi in
> the pump before the water will start to run back up that line. This
> takes power or 'work'.
>
> If you have an empty line with no pressure in it the pump only has to
> hold the pressure of the water column in the pipe when filling from the
> top.
>
> Yes if the tank was a void, then it would be lees 'work' to raise the
> water only to the bottom of the tank, but as soon as the tank has water
> in it, it is fighting back and the physics radically change!
>
> So if you have a pump that can only generate 'say' 50 psi, then your
> truck tank will fill up at a rate of 50 psi out of that 'say' 100 psi
> line if there is no backflow valve.
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's

My physics is a bit rusty here, but IIRC, the pressure created at the bottom
opening will be equal to the weight of a water column (which is the area of
the opening x the height of the water column). This applies whether the
bottom opening is at the side or on the bottom. A fluid exerts equal
pressure against all sides of its container that it is in contact with. What
this means in essence is that it would take slightly less energy to bottom
fill. Any fluid in a container has some amount of stored energy, The wider
and shorter the container is, the less energy it will take to fill it.

Also, like the others said, the energy required to top fill will remain
constant as the barrel fills. For bottom filling, the energy will start out
slightly less, and end up the same as the barrel reaches full.

Chris

Re: Physics/hydraulics of water and barrel
 

"Mike Romain" <romainm@sympatico.ca> wrote in message
news:41A4C55B.4F42B023@sympatico.ca...
> Jeepers wrote:
> >
> > In article <30jsckF3182ubU1@uni-berlin.de>,
> > "Ray Drouillard" <cosmicpam2@comcast.net> wrote:
> >
> > > you will want to have a valve to keep the water from running out
through the pump and
> > > back into the barrel that's in the truck.
> > > Ray Drouillard
> >
> > Same for the top fill hole hose? Won't want to run backwards?
> >
> > I'm gonna use the top fill hole anyway so I don't have to disconnect the
> > drain hose from the cabin.
> >
> > I lost the physics argument, but I had the right idea.
> >
>
> No way you lost the physics argument!
>
> You asked which is easier? This means less 'work'.
>
> If you had a real reservoir there and had 'say' for easy numbers 100 psi
> coming out the bottom pipe, then you 'first' have to build up 100 psi in
> the pump before the water will start to run back up that line. This
> takes power or 'work'.
>
> If you have an empty line with no pressure in it the pump only has to
> hold the pressure of the water column in the pipe when filling from the
> top.
>
> Yes if the tank was a void, then it would be lees 'work' to raise the
> water only to the bottom of the tank, but as soon as the tank has water
> in it, it is fighting back and the physics radically change!
>
> So if you have a pump that can only generate 'say' 50 psi, then your
> truck tank will fill up at a rate of 50 psi out of that 'say' 100 psi
> line if there is no backflow valve.
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's

My physics is a bit rusty here, but IIRC, the pressure created at the bottom
opening will be equal to the weight of a water column (which is the area of
the opening x the height of the water column). This applies whether the
bottom opening is at the side or on the bottom. A fluid exerts equal
pressure against all sides of its container that it is in contact with. What
this means in essence is that it would take slightly less energy to bottom
fill. Any fluid in a container has some amount of stored energy, The wider
and shorter the container is, the less energy it will take to fill it.

Also, like the others said, the energy required to top fill will remain
constant as the barrel fills. For bottom filling, the energy will start out
slightly less, and end up the same as the barrel reaches full.

Chris

Re: Physics/hydraulics of water and barrel
 

"Mike Romain" <romainm@sympatico.ca> wrote in message
news:41A4C55B.4F42B023@sympatico.ca...
> Jeepers wrote:
> >
> > In article <30jsckF3182ubU1@uni-berlin.de>,
> > "Ray Drouillard" <cosmicpam2@comcast.net> wrote:
> >
> > > you will want to have a valve to keep the water from running out
through the pump and
> > > back into the barrel that's in the truck.
> > > Ray Drouillard
> >
> > Same for the top fill hole hose? Won't want to run backwards?
> >
> > I'm gonna use the top fill hole anyway so I don't have to disconnect the
> > drain hose from the cabin.
> >
> > I lost the physics argument, but I had the right idea.
> >
>
> No way you lost the physics argument!
>
> You asked which is easier? This means less 'work'.
>
> If you had a real reservoir there and had 'say' for easy numbers 100 psi
> coming out the bottom pipe, then you 'first' have to build up 100 psi in
> the pump before the water will start to run back up that line. This
> takes power or 'work'.
>
> If you have an empty line with no pressure in it the pump only has to
> hold the pressure of the water column in the pipe when filling from the
> top.
>
> Yes if the tank was a void, then it would be lees 'work' to raise the
> water only to the bottom of the tank, but as soon as the tank has water
> in it, it is fighting back and the physics radically change!
>
> So if you have a pump that can only generate 'say' 50 psi, then your
> truck tank will fill up at a rate of 50 psi out of that 'say' 100 psi
> line if there is no backflow valve.
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's

My physics is a bit rusty here, but IIRC, the pressure created at the bottom
opening will be equal to the weight of a water column (which is the area of
the opening x the height of the water column). This applies whether the
bottom opening is at the side or on the bottom. A fluid exerts equal
pressure against all sides of its container that it is in contact with. What
this means in essence is that it would take slightly less energy to bottom
fill. Any fluid in a container has some amount of stored energy, The wider
and shorter the container is, the less energy it will take to fill it.

Also, like the others said, the energy required to top fill will remain
constant as the barrel fills. For bottom filling, the energy will start out
slightly less, and end up the same as the barrel reaches full.

Chris

Re: Physics/hydraulics of water and barrel
 

In article <hJ4pd.91466$T02.37417@twister.rdc-kc.rr.com>,
"c" <c@me.org> wrote:

> My physics is a bit rusty here, but IIRC, the pressure created at the bottom
> opening will be equal to the weight of a water column (which is the area of
> the opening x the height of the water column). This applies whether the
> bottom opening is at the side or on the bottom. A fluid exerts equal
> pressure against all sides of its container that it is in contact with. What
> this means in essence is that it would take slightly less energy to bottom
> fill. Any fluid in a container has some amount of stored energy, The wider
> and shorter the container is, the less energy it will take to fill it.
>
> Also, like the others said, the energy required to top fill will remain
> constant as the barrel fills. For bottom filling, the energy will start out
> slightly less, and end up the same as the barrel reaches full.
>
> Chris

O.K. my lame-ass attempt at physics argument:

Isn't part of the column the barrel? The barrel has a bigger column in
it's part, than the hose. So the weight of the water column is GREATLY
larger than the one in the hose going to the top. Less water - less
weight, right?

--
Member AAAAAAAA
American Association Against Acronym Abuse And Also Ambiguity.

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Re: Physics/hydraulics of water and barrel
 

In article <hJ4pd.91466$T02.37417@twister.rdc-kc.rr.com>,
"c" <c@me.org> wrote:

> My physics is a bit rusty here, but IIRC, the pressure created at the bottom
> opening will be equal to the weight of a water column (which is the area of
> the opening x the height of the water column). This applies whether the
> bottom opening is at the side or on the bottom. A fluid exerts equal
> pressure against all sides of its container that it is in contact with. What
> this means in essence is that it would take slightly less energy to bottom
> fill. Any fluid in a container has some amount of stored energy, The wider
> and shorter the container is, the less energy it will take to fill it.
>
> Also, like the others said, the energy required to top fill will remain
> constant as the barrel fills. For bottom filling, the energy will start out
> slightly less, and end up the same as the barrel reaches full.
>
> Chris

O.K. my lame-ass attempt at physics argument:

Isn't part of the column the barrel? The barrel has a bigger column in
it's part, than the hose. So the weight of the water column is GREATLY
larger than the one in the hose going to the top. Less water - less
weight, right?

--
Member AAAAAAAA
American Association Against Acronym Abuse And Also Ambiguity.

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Re: Physics/hydraulics of water and barrel
 

In article <hJ4pd.91466$T02.37417@twister.rdc-kc.rr.com>,
"c" <c@me.org> wrote:

> My physics is a bit rusty here, but IIRC, the pressure created at the bottom
> opening will be equal to the weight of a water column (which is the area of
> the opening x the height of the water column). This applies whether the
> bottom opening is at the side or on the bottom. A fluid exerts equal
> pressure against all sides of its container that it is in contact with. What
> this means in essence is that it would take slightly less energy to bottom
> fill. Any fluid in a container has some amount of stored energy, The wider
> and shorter the container is, the less energy it will take to fill it.
>
> Also, like the others said, the energy required to top fill will remain
> constant as the barrel fills. For bottom filling, the energy will start out
> slightly less, and end up the same as the barrel reaches full.
>
> Chris

O.K. my lame-ass attempt at physics argument:

Isn't part of the column the barrel? The barrel has a bigger column in
it's part, than the hose. So the weight of the water column is GREATLY
larger than the one in the hose going to the top. Less water - less
weight, right?

--
Member AAAAAAAA
American Association Against Acronym Abuse And Also Ambiguity.

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Re: OT: Physics/hydraulics of water and barrel
 

If the fill hose touches the bottom of the barrel that is being
filled..... then each system will require the same exact pressure to
fill: The pressure required is the weight of the column of water
(static head); but, since the hose that goes over the top will partly
siphon (the distance from the top of the barrel to the bottomof the
barrel) the pressure requirements will be the same. The only
difference is that for 'starting' the hose that goes over the top, will
require more pressure to lift the water to the top of the bend, but
once the water entirely fills the hose and the sipon effect starts,
then either system will require the same pressure. whew!

In article <moomesa-F31228.08110724112004@news-east.newsfeeds.com>,
Jeepers <moomesa@INVALIDfnbnet.net> wrote:

> O.k. got an argument to solve.
>
> Have a 55 gal. barrel, on a 8 to 10 foot tall platform (to provide water
> in deer camp).
>
> It has three bungs. One on the bottom side (drain/flow). Two on the top
> side. One for vent, one for fill.
>
> There is another barrel in the bed of a pickup, full of water. There are
> two pumps, one hand diaphragm type or one typical 12v bilge type. This
> is the source of water to fill the high barrel.
>
> The argument is that the water can be just as easily pumped into the
> barrel through the drain bung, from below, as it could be through the
> top fill bung. There is an assertion that the pressure inside the hose
> is greater in the lower fill hose than in the upper fill hose, due to
> the weight of the water in the barrel as it fills.
>
> Which, if any, fill location would require more or less force to fill
> this barrel: the top hole or the bottom hole?

Re: OT: Physics/hydraulics of water and barrel
 

If the fill hose touches the bottom of the barrel that is being
filled..... then each system will require the same exact pressure to
fill: The pressure required is the weight of the column of water
(static head); but, since the hose that goes over the top will partly
siphon (the distance from the top of the barrel to the bottomof the
barrel) the pressure requirements will be the same. The only
difference is that for 'starting' the hose that goes over the top, will
require more pressure to lift the water to the top of the bend, but
once the water entirely fills the hose and the sipon effect starts,
then either system will require the same pressure. whew!

In article <moomesa-F31228.08110724112004@news-east.newsfeeds.com>,
Jeepers <moomesa@INVALIDfnbnet.net> wrote:

> O.k. got an argument to solve.
>
> Have a 55 gal. barrel, on a 8 to 10 foot tall platform (to provide water
> in deer camp).
>
> It has three bungs. One on the bottom side (drain/flow). Two on the top
> side. One for vent, one for fill.
>
> There is another barrel in the bed of a pickup, full of water. There are
> two pumps, one hand diaphragm type or one typical 12v bilge type. This
> is the source of water to fill the high barrel.
>
> The argument is that the water can be just as easily pumped into the
> barrel through the drain bung, from below, as it could be through the
> top fill bung. There is an assertion that the pressure inside the hose
> is greater in the lower fill hose than in the upper fill hose, due to
> the weight of the water in the barrel as it fills.
>
> Which, if any, fill location would require more or less force to fill
> this barrel: the top hole or the bottom hole?

Re: OT: Physics/hydraulics of water and barrel
 

If the fill hose touches the bottom of the barrel that is being
filled..... then each system will require the same exact pressure to
fill: The pressure required is the weight of the column of water
(static head); but, since the hose that goes over the top will partly
siphon (the distance from the top of the barrel to the bottomof the
barrel) the pressure requirements will be the same. The only
difference is that for 'starting' the hose that goes over the top, will
require more pressure to lift the water to the top of the bend, but
once the water entirely fills the hose and the sipon effect starts,
then either system will require the same pressure. whew!

In article <moomesa-F31228.08110724112004@news-east.newsfeeds.com>,
Jeepers <moomesa@INVALIDfnbnet.net> wrote:

> O.k. got an argument to solve.
>
> Have a 55 gal. barrel, on a 8 to 10 foot tall platform (to provide water
> in deer camp).
>
> It has three bungs. One on the bottom side (drain/flow). Two on the top
> side. One for vent, one for fill.
>
> There is another barrel in the bed of a pickup, full of water. There are
> two pumps, one hand diaphragm type or one typical 12v bilge type. This
> is the source of water to fill the high barrel.
>
> The argument is that the water can be just as easily pumped into the
> barrel through the drain bung, from below, as it could be through the
> top fill bung. There is an assertion that the pressure inside the hose
> is greater in the lower fill hose than in the upper fill hose, due to
> the weight of the water in the barrel as it fills.
>
> Which, if any, fill location would require more or less force to fill
> this barrel: the top hole or the bottom hole?

Re: OT: Physics/hydraulics of water and barrel
 

In article <241120041442412259%RhmpL33@nospam.net>,
Rich Hampel <RhmpL33@nospam.net> wrote:

> If the fill hose touches the bottom of the barrel that is being
> filled..... then each system will require the same exact pressure to
> fill: The pressure required is the weight of the column of water
> (static head); but, since the hose that goes over the top will partly
> siphon (the distance from the top of the barrel to the bottomof the
> barrel) the pressure requirements will be the same. The only
> difference is that for 'starting' the hose that goes over the top, will
> require more pressure to lift the water to the top of the bend, but
> once the water entirely fills the hose and the sipon effect starts,
> then either system will require the same pressure. whew!

I was clear, no hose over the top. 3 bungs on side of barrel, two at
top, one at bottom. One top one is vent the other is fill.

Why isn't the additional water in the barrel not included as the static
head on the lower fill? There is tremendously more volume in the barrel
at, say half way.

--
Member AAAAAAAA
American Association Against Acronym Abuse And Also Ambiguity.

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