1,000 Boats To Push Flood Waters From Chao Phraya River

[letitbe]

look you might be a total beer swilling typical forang here like me and rest but some people like to enter into a meaningful and philosophical discussion instead of spending our time ogling gogo girls. I am not one of those preferring to use up most of my time ogling my wife and playing with my family but please let those who want to do so without insulting them Now back to my point this time hopefully with slightly better grammar and less joined up words

Look I have a doctorate in physics and can assure you that you are all missing the point about fluid mechanics and the dynamics of a moving solid state sytem such as flood water. I this case Henson's law no longer applies as was proved by a research paper I presented at national physics association in New Yorks annual conference (google Henson's law as disproved byDr Alfred Herbitson at New York physics convention 2004). As my paper clearly proved the normal vectorsFR = V*H squared do not apply and need to be replaced by FR = V*(.85)*H which then means normal friction and increased flow no longer apply. This conclusively proved you can have all boats in universe and it wont makeslightest difference to resultant force S=square root of N x P - G

Where S= Stupidity of a many Thai or other politician N is nonsense and P is possible loss of face of a Thai which could result from him or her just admitting they don't have a clue and Gis gullibility shown in spades of many Thais to believe anything a higher Thai says which of course is a very high figure. The same can also be said of many politicians and public in the west

Splendid summing up sir.

Can I buy you a pint?

And then go on to illustrate how you can't get two pints in to a one pint glass?

(purely for the benefit of others of course)

letitbe: I Googled your string and there were no results found. Please provide a link or document and stop jerking us around.

Thaddeus: QOPF Update (quality-of-posts factor) = 1 / (posts per day) * IQ * 100 / (percent-alcohol-bloodstream (where > 0, otherwise = 1))

sorry seems my paper has been withdrawn from general circulation since Dr Phibious Newbury claims he first came up with this proof in his paper presented to Royal London College of scientists in 2002 I have lodged a counter claim and we both await the decision of the relevant authorities In the meantime I am working on a proof of my my new hypothesis that TV=L+B+W*M

where TV is Thaivisa ops L is load mouth B is bullshit W is without a clue or brain and M is many. I shall publish my proof of this shortly

[cloudhopper]

sorry seems my paper has been withdrawn from general circulation

Bummer professor. Any links to aspects of your work not in dispute?

[letitbe]

No no, it did work, but nobody noticed.

You mean they actually where so stupid they tried it come on your joking but then I did see on Thai news pictures of Yingluk's idea of throwing stones into water and asked my wife to take me to a clinic to dry out or had she put some form of mind bending stuff in my food. I was informed both where incorrect hypothesis and had I not lived here long enough to appreciate the brilliant depths of stupidity the thai government officials could get to except when it was am ater of linign their own pockets and then they actually made people in west seen total morons on that subject

[bkkjames]

I seen with my own eyes (will upload a photo later) their latest attempt to move the water using 25 tug boats tide up to the pier at big c ratburana today.

Needless to say.....pfff. Tide is coming back in it appears and river is rising. Started to rain as well.

[MaxYakov]

< snipped distracting preamble, leaving a political/cultural statement? >

Where S= Stupidity of a many Thai or other politician N is nonsense and P is possible loss of face of a Thai which could result from him or her just admitting they don't have a clue and Gis gullibility shown in spades of many Thais to believe anything a higher Thai says which of course is a very high figure. The same can also be said of many politicians and public in the west

Splendid summing up sir.

Can I buy you a pint?

And then go on to illustrate how you can't get two pints in to a one pint glass?

(purely for the benefit of others of course)

letitbe: I Googled your string and there were no results found. Please provide a link or document and stop jerking us around.

Thaddeus: QOPF Update (quality-of-posts factor) = 1 / (posts per day) * IQ * 100 / (percent-alcohol-bloodstream (where > 0, otherwise = 1))

sorry seems my paper has been withdrawn from general circulation since Dr Phibious Newbury claims he first came up with this proof in his paper presented to Royal London College of scientists in 2002 I have lodged a counter claim and we both await the decision of the relevant authorities In the meantime I am working on a proof of my my new hypothesis that TV=L+B+W*M

where TV is Thaivisa ops L is load mouth B is bullshit W is without a clue or brain and M is many. I shall publish my proof of this shortly

Please refer to and plug your personal values into the QOPF formula. Reminds me that I should develop a more descriptive, hyperbolic function for the final (1 / percent-alcohol-bloodstream) term. Maybe I should add some new terms for other hallucinogens?

Edited October 23, 2011 by MaxYakov

[Thaddeus]

I seen with my own eyes (will upload a photo later) their latest attempt to move the water using 25 tug boats tide up to the pier at big c ratburana today.

They may be attempting to tow Big C upriver.

You never know.

[bkkjames]

I think they have all parked there for lunch.

[ResX]

The way to test the idea is to measure flow speed before the boats' motors are throttled, and then measure flow speed after. You could add measurements for volume also. The stickler is, Thai authorities aren't versed in science and probably don't have much/many scientific/measuring tools at hand. Thailand largely runs on belief systems (religion, occult, appearances, pomp, pronouncements by VIPs) rather than science and reality.

I see the 1,000 boat idea this way: The Chao Praya, its final KM's, is essentially a flat body of water. Any turbulence on its surface (caused by boat propellers) will speed a comparative tiny amount of surface water for ten or twenty meters, until it hits a wall of water at its same level, and quickly eddies down to the river's ambient speed. The overall gain in momentum is zero. The only people benefiting are those selling fossil fuels for the boats, and perhaps the boat owners who may be getting paid for the ridiculous spectacle. Those within sniffing distance are having a bunch more pollutants added to the air.

Actually no. It is not a flat body. Flat water body hasn't move. It moves because the is a small pressure gradient between upstream and the downstream. You can take any elevation of the flooded area. You will definitely find it is higher that the sea level. Otherwise the water tastes salty.

[MaxYakov]

The way to test the idea is to measure flow speed before the boats' motors are throttled, and then measure flow speed after. You could add measurements for volume also. The stickler is, Thai authorities aren't versed in science and probably don't have much/many scientific/measuring tools at hand. Thailand largely runs on belief systems (religion, occult, appearances, pomp, pronouncements by VIPs) rather than science and reality.

I see the 1,000 boat idea this way: The Chao Praya, its final KM's, is essentially a flat body of water. Any turbulence on its surface (caused by boat propellers) will speed a comparative tiny amount of surface water for ten or twenty meters, until it hits a wall of water at its same level, and quickly eddies down to the river's ambient speed. The overall gain in momentum is zero. The only people benefiting are those selling fossil fuels for the boats, and perhaps the boat owners who may be getting paid for the ridiculous spectacle. Those within sniffing distance are having a bunch more pollutants added to the air.

Actually no. It is not a flat body. Flat water body hasn't move. It moves because the is a small pressure gradient between upstream and the downstream. You can take any elevation of the flooded area. You will definitely find it is higher that the sea level. Otherwise the water tastes salty.

I think you're in safe waters with the pressure gradient explanation, ResX. However you (understandably) begged the question of:

Any turbulence on its surface (caused by boat propellers) will speed a comparative tiny amount of surface water for ten or twenty meters, until it hits a wall of water at its same level, and quickly eddies down to the river's ambient speed. The overall gain in momentum is zero.

Which, it seems to me, is the crux of the Minister's experiment and would mean that the energy transformation would have to be to heat (or some other form?) if 'gain in momentum' (in any/all directions?) is 'zero'. I think I'm having deja vu here, but aside from the issue of the scale of the energy provided to the river, the only one remaining is this one (actually, two or three):

Will it materially increase river water velocity in the downstream direction and, if so, how much and with what (percent of prop output) efficiency?

I'm also having a little trouble with his terms 'hits a wall of water' and 'quickly eddies down'. Details, details.

It strikes me as a good 'MythBusters' candidate (as it has others), but they'd probably opt out for political reasons.

After all, didn't they demonstrate empirically that a lead (Pb) balloon could float in air, ignoring how utterly impractical it was to do so?

Could this 'lead balloon' experiment be analogous to the Minister's 'water diversion' experiment performed by conscripted diesel boats on the CP?

Edited October 23, 2011 by MaxYakov

[ResX]

The way to test the idea is to measure flow speed before the boats' motors are throttled, and then measure flow speed after. You could add measurements for volume also. The stickler is, Thai authorities aren't versed in science and probably don't have much/many scientific/measuring tools at hand. Thailand largely runs on belief systems (religion, occult, appearances, pomp, pronouncements by VIPs) rather than science and reality.

I see the 1,000 boat idea this way: The Chao Praya, its final KM's, is essentially a flat body of water. Any turbulence on its surface (caused by boat propellers) will speed a comparative tiny amount of surface water for ten or twenty meters, until it hits a wall of water at its same level, and quickly eddies down to the river's ambient speed. The overall gain in momentum is zero. The only people benefiting are those selling fossil fuels for the boats, and perhaps the boat owners who may be getting paid for the ridiculous spectacle. Those within sniffing distance are having a bunch more pollutants added to the air.

Actually no. It is not a flat body. Flat water body hasn't move. It moves because the is a small pressure gradient between upstream and the downstream. You can take any elevation of the flooded area. You will definitely find it is higher that the sea level. Otherwise the water tastes salty.

I think you're in safe waters with the pressure gradient explanation, ResX. However you (understandably) begged the question of:

Any turbulence on its surface (caused by boat propellers) will speed a comparative tiny amount of surface water for ten or twenty meters, until it hits a wall of water at its same level, and quickly eddies down to the river's ambient speed. The overall gain in momentum is zero.

Which, it seems to me, is the crux of the Minister's experiment and would mean that the energy transformation would have to be to heat (or some other form?) if 'gain in momentum' (in any/all directions?) is 'zero'. I think I'm having deja vu here, but aside from the issue of the scale of the energy provided to the river, the only one remaining is this one (actually, two or three):

Will it materially increase river water velocity in the downstream direction and, if so, how much and with what (percent of prop output) efficiency?

I'm also having a little trouble with his terms 'hits a wall of water' and 'quickly eddies down'. Details, details.

It strikes me as a good 'MythBusters' candidate (as it has others), but they'd probably opt out for political reasons.

After all, didn't they demonstrate empirically that a lead (Pb) balloon could float in air, ignoring how utterly impractical it was to do so?

Could this 'lead balloon' experiment be analogous to the Minister's 'water diversion' experiment performed by conscripted diesel boats on the CP?

First of all about efficiency of the propeller. It could be greater than 85% if the boat is throttled at the most efficiency RPM. I might get it wrong before by predicting it was well below 15%. But then I knew for sure that it has higher than 85% even when I predicted it was well below 15%. I just lumped with potential loss of energy due to drag. To put in right perspectuve, we better make clear separation about what the propeller can deliver and what end result. Overall, energy conversion efficiency from fuel to propeller efficiency, I think you can refer your own post.

"I think you're in safe waters with the pressure gradient explanation, ResX. However you (understandably) begged the question of:

Any turbulence on its surface (caused by boat propellers) will speed a comparative tiny amount of surface water for ten or twenty meters, until it hits a wall of water at its same level, and quickly eddies down to the river's ambient speed. The overall gain in momentum is zero.

Which, it seems to me, is the crux of the Minister's experiment and would mean that the energy transformation would have to be to heat (or some other form?) if 'gain in momentum' (in any/all directions?) is 'zero'. I think I'm having deja vu here, but aside from the issue of the scale of the energy provided to the river, the only one remaining is this one (actually, two or three):"

Have you ever realized that I didn't say the way the initiative is carried out currently is going to work. Why? You have just mentioned one of the probable scenario. But this is the only possible scenario and it has little thing to do with "the propeller capability" to increase water velocity & flow rate. Let me elaborate further.

One of the posters modelled the body of water at the back of the propeller is a solid wall. The propeller can increase water velocity before hitting the wall. The water needs huge amount of energy to pass through the wall. It does not have it. It requires far less energy to move back to the entry of the propeller. Then we have a complete recirculation scenario. Net volume leaving the walled section is zero. This is clear cut "it doesn't work scenario". Now let me present a "100% sure it is going to work scenario". Put the propeller just before the flow bottle neck cross section for any flood plain. Just after the bottle neck of that flood plain it follows by a hydraulic jump 2m down. When the propeller pushes the water down this hydraulic jump. There will be no more issue regarding zero net momentum. The water cannot reverse back. No matter what we can draw down this flood plain faster. But the flood level for subsequent flood plain will increase. If it is okay with it why bother. If it is not okay then employ the same procedure at its bottle neck too.

In reality what we have down there is something in between "it doesn't work scenario" and "100% sure it is going to work scenario". Whatever it may be case, we only can know the final outcome by understanding site conditions.

"I'm also having a little trouble with his terms 'hits a wall of water' and 'quickly eddies down'. Details, details."

I have explained this before, I think. Quite a long explanation that we can derive from Bernoulli Continuity Equation. Again what ever the case, it is procedural issue rather than conceptual.

[rogerdee123]

in homage to being scientifically creative along the same lines as the 1000 boats, and jet wash etc ....

I'm wondering if any of you scientists could give your reaction to this idea.

Of course there is always the risk that some other brilliant mind such as mind has thought of this ... I'm still not going back to read all the threads to this topic!

What would happen if everyone in Bangkok flushed their toilets at the same time ?

I remember seeing a movie some years ago when everyone in ?? NYC I think? flushed their toilets in unison and then proceeded to the window and screamed something like .... " I'm pissed off and I'm not going to take it anymore".

THis apparently had the effect of changing many things for the positive.

However I am more particularly interested in the impact on hydrological realities and if this sudden surge in toilet effluent could perhaps give ... well you know ... give a boost to a push to some extent ... to the flow of the Chaopraya ..... particularly during the high tide period.

Or would it perhaps result in something like ... heaven forbid ... flooding in Nakon Nowwhere or some other unfortunate location.

Edited October 23, 2011 by rogerdee123

[Thaddeus]

So, given the last couple of posts from Max and Res, can we conclude that this project and the way that it has been implemented has been pointless, or as close to pointless as you can get while looking like there is one.

Plus, it has wasted a large amount of fuel and used resources that would have been much more beneficial elsewhere.

[rogerdee123]

So, given the last couple of posts from Max and Res, can we conclude that this project and the way that it has been implemented has been pointless, or as close to pointless as you can get while looking like there is one.

Plus, it has wasted a large amount of fuel and used resources that would have been much more beneficial elsewhere.

On a serious note ... all these boats could have been effectively used to evacuate people ... maybe with the help of the jet ski brigade.

[TAWP]

On a serious note ... all these boats could have been effectively used to evacuate people ... maybe with the help of the jet ski brigade.

Finally, a good suggestion in this thread that is spot on.

[MaxYakov]

I think you're in safe waters with the pressure gradient explanation, ResX. However you (understandably) begged the question of:

Any turbulence on its surface (caused by boat propellers) will speed a comparative tiny amount of surface water for ten or twenty meters, until it hits a wall of water at its same level, and quickly eddies down to the river's ambient speed. The overall gain in momentum is zero.

Which, it seems to me, is the crux of the Minister's experiment and would mean that the energy transformation would have to be to heat (or some other form?) if 'gain in momentum' (in any/all directions?) is 'zero'. I think I'm having deja vu here, but aside from the issue of the scale of the energy provided to the river, the only one remaining is this one (actually, two or three):

Will it materially increase river water velocity in the downstream direction and, if so, how much and with what (percent of prop output) efficiency?

I'm also having a little trouble with his terms 'hits a wall of water' and 'quickly eddies down'. Details, details.

It strikes me as a good 'MythBusters' candidate (as it has others), but they'd probably opt out for political reasons.

After all, didn't they demonstrate empirically that a lead (Pb) balloon could float in air, ignoring how utterly impractical it was to do so?

Could this 'lead balloon' experiment be analogous to the Minister's 'water diversion' experiment performed by conscripted diesel boats on the CP?

First of all about efficiency of the propeller. It could be greater than 85% if the boat is throttled at the most efficiency RPM. I might get it wrong before by predicting it was well below 15%. But then I knew for sure that it has higher than 85% even when I predicted it was well below 15%. I just lumped with potential loss of energy due to drag. To put in right perspectuve, we better make clear separation about what the propeller can deliver and what end result. Overall, energy conversion efficiency from fuel to propeller efficiency, I think you can refer your own post.

"I think you're in safe waters with the pressure gradient explanation, ResX. However you (understandably) begged the question of:

Any turbulence on its surface (caused by boat propellers) will speed a comparative tiny amount of surface water for ten or twenty meters, until it hits a wall of water at its same level, and quickly eddies down to the river's ambient speed. The overall gain in momentum is zero.

Which, it seems to me, is the crux of the Minister's experiment and would mean that the energy transformation would have to be to heat (or some other form?) if 'gain in momentum' (in any/all directions?) is 'zero'. I think I'm having deja vu here, but aside from the issue of the scale of the energy provided to the river, the only one remaining is this one (actually, two or three):"

Have you ever realized that I didn't say the way the initiative is carried out currently is going to work. Why? You have just mentioned one of the probable scenario. But this is the only possible scenario and it has little thing to do with "the propeller capability" to increase water velocity & flow rate. Let me elaborate further.

One of the posters modelled the body of water at the back of the propeller is a solid wall. The propeller can increase water velocity before hitting the wall. The water needs huge amount of energy to pass through the wall. It does not have it. It requires far less energy to move back to the entry of the propeller. Then we have a complete recirculation scenario. Net volume leaving the walled section is zero. This is clear cut "it doesn't work scenario". Now let me present a "100% sure it is going to work scenario". Put the propeller just before the flow bottle neck cross section for any flood plain. Just after the bottle neck of that flood plain it follows by a hydraulic jump 2m down. When the propeller pushes the water down this hydraulic jump. There will be no more issue regarding zero net momentum. The water cannot reverse back. No matter what we can draw down this flood plain faster. But the flood level for subsequent flood plain will increase. If it is okay with it why bother. If it is not okay then employ the same procedure at its bottle neck too.

In reality what we have down there is something in between "it doesn't work scenario" and "100% sure it is going to work scenario". Whatever it may be case, we only can know the final outcome by understanding site conditions.

"I'm also having a little trouble with his terms 'hits a wall of water' and 'quickly eddies down'. Details, details."

I have explained this before, I think. Quite a long explanation that we can derive from Bernoulli Continuity Equation. Again what ever the case, it is procedural issue rather than conceptual.

I eliminated 'propeller efficiency' in my posted-earlier ideal model by specifying 1000 HP at propeller output (not shaft input) in order to evade distracting discussions of it. The only reason I used HP at all was so that readers could relate to the power rather than to joules or watts.

I agree that dumping the water into a potential energy well would eliminate any potential for re-circulation, but isn't that changing things a bit too much from the Minister's experiment?

I believe that this is both a conceptual and procedural issue. One cannot establish the procedural issues, until the conceptual issues have been reasonably resolved. Unless one is spending other people's (tax-payers) money, that is.

As far as the 'hit the wall' hypothesis goes, I something in this Proceedings of the First U.S. Waterjet Conference that has a different model for submerged water jets:

THEORY OF SUBMERGED JETS

A submerged jet is the fluid flow issuing from a nozzle into a surrounding of the same fluid. In particular, a free jet is defined as a submerged jet issuing into a stagnant medium. The velocity at the nozzle exit is approximately uniform and a potential core can be observed which maintains a constant velocity, but decreases in size until finally it vanishes. A growing boundary layer appears, which is due to mixing and entrainment effects between the stream issuing from the nozzle and the surrounding fluid, see Figure 1. The flow field of a circular laminar jet can be found by solving the following system of equations for u (r, z) and v (r, z).

It can be argued, I suppose, that a recirculation path does not exist in this particular illustration of 'Theory of Submerged Jets', but I would think that, given the velocities and the law of inertia, that recirculation is unlikely, as well, with a propeller example. Even more unlikely if it is a ducted propeller. Also, there is the current of the river itself that would have to be overcome in order to support recirculation, no?

However, one caveat is that the absolute jet velocities for this model were not mentioned. Another is that the propeller produces a 'solid wall' of water. I believe from the document I posted that it is a little more complicated than that. Is anyone willing to don a scuba outfit and go down to the river for some empirical measurement? Or shall we wait for the 'MythBusters'?

If this model can be considered anywhere near indicative of what is happening to the Minister's boats' prop wash, then the next question is why do the downstream velocities diminish in the manner they do as illustrated in Figure 1 (attachment).

[Tokay]

All I know is I seriously want to import several thousand of these immediately anyone in?

You stand upright and dangle your feet in ones with built in waders or you can wear them separately like this one and sit in it so it keeps you dry and out the crap water. Endless possibilities market wise.

Brilliant.

Get the ones where you can put beer in it and it will be a hit.

[MaxYakov]

So, given the last couple of posts from Max and Res, can we conclude that this project and the way that it has been implemented has been pointless, or as close to pointless as you can get while looking like there is one.

Plus, it has wasted a large amount of fuel and used resources that would have been much more beneficial elsewhere.

Wish I could help you out with your questions but, due to, what is in my view, the sensitive nature of this particular project, I'm trying to limit my discussion and speculation to issues of physics and metrics of an ideal model. Frankly, I don't feel very comfortable, believe it or not, with doing only that.

[ResX]

I think you're in safe waters with the pressure gradient explanation, ResX. However you (understandably) begged the question of:

Any turbulence on its surface (caused by boat propellers) will speed a comparative tiny amount of surface water for ten or twenty meters, until it hits a wall of water at its same level, and quickly eddies down to the river's ambient speed. The overall gain in momentum is zero.

Which, it seems to me, is the crux of the Minister's experiment and would mean that the energy transformation would have to be to heat (or some other form?) if 'gain in momentum' (in any/all directions?) is 'zero'. I think I'm having deja vu here, but aside from the issue of the scale of the energy provided to the river, the only one remaining is this one (actually, two or three):

Will it materially increase river water velocity in the downstream direction and, if so, how much and with what (percent of prop output) efficiency?

I'm also having a little trouble with his terms 'hits a wall of water' and 'quickly eddies down'. Details, details.

It strikes me as a good 'MythBusters' candidate (as it has others), but they'd probably opt out for political reasons.

After all, didn't they demonstrate empirically that a lead (Pb) balloon could float in air, ignoring how utterly impractical it was to do so?

Could this 'lead balloon' experiment be analogous to the Minister's 'water diversion' experiment performed by conscripted diesel boats on the CP?

First of all about efficiency of the propeller. It could be greater than 85% if the boat is throttled at the most efficiency RPM. I might get it wrong before by predicting it was well below 15%. But then I knew for sure that it has higher than 85% even when I predicted it was well below 15%. I just lumped with potential loss of energy due to drag. To put in right perspectuve, we better make clear separation about what the propeller can deliver and what end result. Overall, energy conversion efficiency from fuel to propeller efficiency, I think you can refer your own post.

"I think you're in safe waters with the pressure gradient explanation, ResX. However you (understandably) begged the question of:

Any turbulence on its surface (caused by boat propellers) will speed a comparative tiny amount of surface water for ten or twenty meters, until it hits a wall of water at its same level, and quickly eddies down to the river's ambient speed. The overall gain in momentum is zero.

Which, it seems to me, is the crux of the Minister's experiment and would mean that the energy transformation would have to be to heat (or some other form?) if 'gain in momentum' (in any/all directions?) is 'zero'. I think I'm having deja vu here, but aside from the issue of the scale of the energy provided to the river, the only one remaining is this one (actually, two or three):"

Have you ever realized that I didn't say the way the initiative is carried out currently is going to work. Why? You have just mentioned one of the probable scenario. But this is the only possible scenario and it has little thing to do with "the propeller capability" to increase water velocity & flow rate. Let me elaborate further.

One of the posters modelled the body of water at the back of the propeller is a solid wall. The propeller can increase water velocity before hitting the wall. The water needs huge amount of energy to pass through the wall. It does not have it. It requires far less energy to move back to the entry of the propeller. Then we have a complete recirculation scenario. Net volume leaving the walled section is zero. This is clear cut "it doesn't work scenario". Now let me present a "100% sure it is going to work scenario". Put the propeller just before the flow bottle neck cross section for any flood plain. Just after the bottle neck of that flood plain it follows by a hydraulic jump 2m down. When the propeller pushes the water down this hydraulic jump. There will be no more issue regarding zero net momentum. The water cannot reverse back. No matter what we can draw down this flood plain faster. But the flood level for subsequent flood plain will increase. If it is okay with it why bother. If it is not okay then employ the same procedure at its bottle neck too.

In reality what we have down there is something in between "it doesn't work scenario" and "100% sure it is going to work scenario". Whatever it may be case, we only can know the final outcome by understanding site conditions.

"I'm also having a little trouble with his terms 'hits a wall of water' and 'quickly eddies down'. Details, details."

I have explained this before, I think. Quite a long explanation that we can derive from Bernoulli Continuity Equation. Again what ever the case, it is procedural issue rather than conceptual.

I eliminated 'propeller efficiency' in my posted-earlier ideal model by specifying 1000 HP at propeller output (not shaft input) in order to evade distracting discussions of it. The only reason I used HP at all was so that readers could relate to the power rather than to joules or watts.

I agree that dumping the water into a potential energy well would eliminate any potential for re-circulation, but isn't that changing things a bit too much from the Minister's experiment?

I believe that this is both a conceptual and procedural issue. One cannot establish the procedural issues, until the conceptual issues have been reasonably resolved. Unless one is spending other people's (tax-payers) money, that is.

As far as the 'hit the wall' hypothesis goes, I something in this Proceedings of the First U.S. Waterjet Conference that has a different model for submerged water jets:

THEORY OF SUBMERGED JETS

A submerged jet is the fluid flow issuing from a nozzle into a surrounding of the same fluid. In particular, a free jet is defined as a submerged jet issuing into a stagnant medium. The velocity at the nozzle exit is approximately uniform and a potential core can be observed which maintains a constant velocity, but decreases in size until finally it vanishes. A growing boundary layer appears, which is due to mixing and entrainment effects between the stream issuing from the nozzle and the surrounding fluid, see Figure 1. The flow field of a circular laminar jet can be found by solving the following system of equations for u (r, z) and v (r, z).

It can be argued, I suppose, that a recirculation path does not exist in this particular illustration of 'Theory of Submerged Jets', but I would think that, given the velocities and the law of inertia, that recirculation is unlikely, as well, with a propeller example. Even more unlikely if it is a ducted propeller. Also, there is the current of the river itself that would have to be overcome in order to support recirculation, no?

However, one caveat is that the absolute jet velocities for this model were not mentioned. Another is that the propeller produces a 'solid wall' of water. I believe from the document I posted that it is a little more complicated than that. Is anyone willing to don a scuba outfit and go down to the river for some empirical measurement? Or shall we wait for the 'MythBusters'?

If this model can be considered anywhere near indicative of what is happening to the Minister's boats' prop wash, then the next question is why do the downstream velocities diminish in the manner they do as illustrated in Figure 1 (attachment).

"If this model can be considered anywhere near indicative of what is happening to the Minister's boats' prop wash, then the next question is why do the downstream velocities diminish in the manner they do as illustrated in Figure 1 (attachment)

Because there is no such thing of "Velocity is conserved, cannot be created nor destroyed". Have you ever heard "the law of conservation of velocity?" ....Just joking. In this case you have to view the problem around conservation of momentum to get a clear picture. Tell me if you need further explanation.

A boat propeller is purposely designed to have axial flow at its entry and exit with least pressure rise across it. You you can expect minimum radial component to the linear velocity of the propeller, especially at its optimum RPM . This gives optimum angle of attack at point of entry and exit of the propeller. Thus, you can expect a very efficient energy transfer. Then, we have another laws of physics that govern exit velocity of the propeller.......

[MaxYakov]

"If this model can be considered anywhere near indicative of what is happening to the Minister's boats' prop wash, then the next question is why do the downstream velocities diminish in the manner they do as illustrated in Figure 1 (attachment)

Because there is no such thing of "Velocity is conserved, cannot be created nor destroyed". Have you ever heard "the law of conservation of velocity?" ....Just joking. In this case you have to view the problem around conservation of momentum to get a clear picture. Tell me if you need further explanation.

A boat propeller is purposely designed to have axial flow at its entry and exit with least pressure rise across it. You you can expect minimum radial component to the linear velocity of the propeller, especially at its optimum RPM . This gives optimum angle of attack at point of entry and exit of the propeller. Thus, you can expect a very efficient energy transfer. Then, we have another laws of physics that govern exit velocity of the propeller.......

I knew it! I just knew there was a sense of humor submerged deeply within Reservoir X.

Before we get too carried away slapping each other on the back and before another less-than-casually-observing poster jumps on it, maybe we should take a look at what some other government agencies (Smithsonian/NASA) have been up to while probably nobody has been paying much attention: A conservation-of-velocity law for inviscid fluids . Another fine example of tax-payer's money well-spent invested.

The Euler equations for an inviscid barotropic fluid (rho = rho)(p) lead to a conversation law for the tangential component of surface velocity. The conservation law has been invoked in an approximate way in the past without having been explicitly stated. Here we derive the general form of the conservation law and, for irrotational flows, point out its relation to Bernouli's law. We then illustrate its use in a nonlinear surface wave model and compare results with experimental profiles for solitary waves in converging/diverging channels. The Korteweg-deVries theory originally used to interpret the experiment does not account for some features seen in the data, such as an oscillatory tail produced when a solitary wave moves through a diverging channel. By contrast, results given here, which derive from a model that explicitly conserves mass and velocity, faithfully reproduce the prominent features of the experiment.

Do you suppose there is much 'inviscid barotropic fluid' in the Chao Phraya these days? Anyway, I thought you might appreciate this since it mentions Bernouli's law. Just joking!

[rubl]

So, given the last couple of posts from Max and Res, can we conclude that this project and the way that it has been implemented has been pointless, or as close to pointless as you can get while looking like there is one.

Plus, it has wasted a large amount of fuel and used resources that would have been much more beneficial elsewhere.

Always look on the bright side. These fools, idiots and other useful people while busy with their very interesting scientific experiment were not in the way obstructing others who were busy helping with sandbags, refugees, handing out food packages, etc., etc.

[ResX]

"If this model can be considered anywhere near indicative of what is happening to the Minister's boats' prop wash, then the next question is why do the downstream velocities diminish in the manner they do as illustrated in Figure 1 (attachment)

Because there is no such thing of "Velocity is conserved, cannot be created nor destroyed". Have you ever heard "the law of conservation of velocity?" ....Just joking. In this case you have to view the problem around conservation of momentum to get a clear picture. Tell me if you need further explanation.

A boat propeller is purposely designed to have axial flow at its entry and exit with least pressure rise across it. You you can expect minimum radial component to the linear velocity of the propeller, especially at its optimum RPM . This gives optimum angle of attack at point of entry and exit of the propeller. Thus, you can expect a very efficient energy transfer. Then, we have another laws of physics that govern exit velocity of the propeller.......

I knew it! I just knew there was a sense of humor submerged deeply within Reservoir X.

Before we get too carried away slapping each other on the back and before another less-than-casually-observing poster jumps on it, maybe we should take a look at what some other government agencies (Smithsonian/NASA) have been up to while probably nobody has been paying much attention: A conservation-of-velocity law for inviscid fluids . Another fine example of tax-payer's money well-spent invested.

The Euler equations for an inviscid barotropic fluid (rho = rho)(p) lead to a conversation law for the tangential component of surface velocity. The conservation law has been invoked in an approximate way in the past without having been explicitly stated. Here we derive the general form of the conservation law and, for irrotational flows, point out its relation to Bernouli's law. We then illustrate its use in a nonlinear surface wave model and compare results with experimental profiles for solitary waves in converging/diverging channels. The Korteweg-deVries theory originally used to interpret the experiment does not account for some features seen in the data, such as an oscillatory tail produced when a solitary wave moves through a diverging channel. By contrast, results given here, which derive from a model that explicitly conserves mass and velocity, faithfully reproduce the prominent features of the experiment.

Do you suppose there is much 'inviscid barotropic fluid' in the Chao Phraya these days? Anyway, I thought you might appreciate this since it mentions Bernouli's law. Just joking!

Res=Reservoir? What should I say?

[ResX]

I think you're in safe waters with the pressure gradient explanation, ResX. However you (understandably) begged the question of:

Any turbulence on its surface (caused by boat propellers) will speed a comparative tiny amount of surface water for ten or twenty meters, until it hits a wall of water at its same level, and quickly eddies down to the river's ambient speed. The overall gain in momentum is zero.

Which, it seems to me, is the crux of the Minister's experiment and would mean that the energy transformation would have to be to heat (or some other form?) if 'gain in momentum' (in any/all directions?) is 'zero'. I think I'm having deja vu here, but aside from the issue of the scale of the energy provided to the river, the only one remaining is this one (actually, two or three):

Will it materially increase river water velocity in the downstream direction and, if so, how much and with what (percent of prop output) efficiency?

I'm also having a little trouble with his terms 'hits a wall of water' and 'quickly eddies down'. Details, details.

It strikes me as a good 'MythBusters' candidate (as it has others), but they'd probably opt out for political reasons.

After all, didn't they demonstrate empirically that a lead (Pb) balloon could float in air, ignoring how utterly impractical it was to do so?

Could this 'lead balloon' experiment be analogous to the Minister's 'water diversion' experiment performed by conscripted diesel boats on the CP?

First of all about efficiency of the propeller. It could be greater than 85% if the boat is throttled at the most efficiency RPM. I might get it wrong before by predicting it was well below 15%. But then I knew for sure that it has higher than 85% even when I predicted it was well below 15%. I just lumped with potential loss of energy due to drag. To put in right perspectuve, we better make clear separation about what the propeller can deliver and what end result. Overall, energy conversion efficiency from fuel to propeller efficiency, I think you can refer your own post.

"I think you're in safe waters with the pressure gradient explanation, ResX. However you (understandably) begged the question of:

Any turbulence on its surface (caused by boat propellers) will speed a comparative tiny amount of surface water for ten or twenty meters, until it hits a wall of water at its same level, and quickly eddies down to the river's ambient speed. The overall gain in momentum is zero.

Which, it seems to me, is the crux of the Minister's experiment and would mean that the energy transformation would have to be to heat (or some other form?) if 'gain in momentum' (in any/all directions?) is 'zero'. I think I'm having deja vu here, but aside from the issue of the scale of the energy provided to the river, the only one remaining is this one (actually, two or three):"

Have you ever realized that I didn't say the way the initiative is carried out currently is going to work. Why? You have just mentioned one of the probable scenario. But this is the only possible scenario and it has little thing to do with "the propeller capability" to increase water velocity & flow rate. Let me elaborate further.

One of the posters modelled the body of water at the back of the propeller is a solid wall. The propeller can increase water velocity before hitting the wall. The water needs huge amount of energy to pass through the wall. It does not have it. It requires far less energy to move back to the entry of the propeller. Then we have a complete recirculation scenario. Net volume leaving the walled section is zero. This is clear cut "it doesn't work scenario". Now let me present a "100% sure it is going to work scenario". Put the propeller just before the flow bottle neck cross section for any flood plain. Just after the bottle neck of that flood plain it follows by a hydraulic jump 2m down. When the propeller pushes the water down this hydraulic jump. There will be no more issue regarding zero net momentum. The water cannot reverse back. No matter what we can draw down this flood plain faster. But the flood level for subsequent flood plain will increase. If it is okay with it why bother. If it is not okay then employ the same procedure at its bottle neck too.

In reality what we have down there is something in between "it doesn't work scenario" and "100% sure it is going to work scenario". Whatever it may be case, we only can know the final outcome by understanding site conditions.

"I'm also having a little trouble with his terms 'hits a wall of water' and 'quickly eddies down'. Details, details."

I have explained this before, I think. Quite a long explanation that we can derive from Bernoulli Continuity Equation. Again what ever the case, it is procedural issue rather than conceptual.

I eliminated 'propeller efficiency' in my posted-earlier ideal model by specifying 1000 HP at propeller output (not shaft input) in order to evade distracting discussions of it. The only reason I used HP at all was so that readers could relate to the power rather than to joules or watts.

I agree that dumping the water into a potential energy well would eliminate any potential for re-circulation, but isn't that changing things a bit too much from the Minister's experiment?

I believe that this is both a conceptual and procedural issue. One cannot establish the procedural issues, until the conceptual issues have been reasonably resolved. Unless one is spending other people's (tax-payers) money, that is.

As far as the 'hit the wall' hypothesis goes, I something in this Proceedings of the First U.S. Waterjet Conference that has a different model for submerged water jets:

THEORY OF SUBMERGED JETS

A submerged jet is the fluid flow issuing from a nozzle into a surrounding of the same fluid. In particular, a free jet is defined as a submerged jet issuing into a stagnant medium. The velocity at the nozzle exit is approximately uniform and a potential core can be observed which maintains a constant velocity, but decreases in size until finally it vanishes. A growing boundary layer appears, which is due to mixing and entrainment effects between the stream issuing from the nozzle and the surrounding fluid, see Figure 1. The flow field of a circular laminar jet can be found by solving the following system of equations for u (r, z) and v (r, z).

It can be argued, I suppose, that a recirculation path does not exist in this particular illustration of 'Theory of Submerged Jets', but I would think that, given the velocities and the law of inertia, that recirculation is unlikely, as well, with a propeller example. Even more unlikely if it is a ducted propeller. Also, there is the current of the river itself that would have to be overcome in order to support recirculation, no?

However, one caveat is that the absolute jet velocities for this model were not mentioned. Another is that the propeller produces a 'solid wall' of water. I believe from the document I posted that it is a little more complicated than that. Is anyone willing to don a scuba outfit and go down to the river for some empirical measurement? Or shall we wait for the 'MythBusters'?

If this model can be considered anywhere near indicative of what is happening to the Minister's boats' prop wash, then the next question is why do the downstream velocities diminish in the manner they do as illustrated in Figure 1 (attachment).

If you believe no recirculation is going to take place, then we have a lead. Before that let me explain your concern why that velocity is faded away after some some distance. Assuming swept area of cylinder liked velocity that is produced by the propeller is 1m2. The water has exit velocity of 3m/s relative to stationary frame of reference. As it travels away from the stationary propeller the velocity cylinder will drag the surrounding water to move together. The flow model is definitely viscous flow. Not inviscid. As the the water moves further, the surface area of contact with slow moving water will become bigger. Eventually at some distance away, the exit velocity has become very small.

From conservation of momentum, if you can plot average velocity versus distance from the propeller exit point, for two cases namely with the propeller and without the propeller , you can see that the velocity at the same distance from exit point of the propeller will always higher in favor of with the propeller. But then both velocities approaching almost the same value as the distance gets further. Theoretically they never be the same. Otherwise, conservation of momentum is violated. Practically, they looked the same.

Let say after 50 m after propeller exit, there is no significant change in river velocity. What happens if you put another propeller to supply kinetic energy to the moving water at this point? Then another one 50m down stream .... until river mouth? If you believe no recirculation will take place, how you are going to argue that conceptually the flow remains the same? You can see it clearly that the water at that particular stream moves faster then as if the propellers are not there. Next, how about the second series of propellers. The third one... the fourth one. .. You can place all the way across the the river stream. After all you have 1000boats with you.

I think you can still recall the image that illustrated the concept to vent exhaust gasses from a road that you posted a few days ago. The concept works well for a road tunnel. Why the same concept cannot work for a river? The physics behind it, as far as I can see, are exactly the same.

[realthaideal]

I appreciate Max Yakov's and LetItBe's efforts to carry on a rational explanation of things. However, I'm also a fan of less rational caricature as LetItBe has started to explore. Enough of Bernouli, and on to Plodprasop's Principle, I say ! Or how about the minister's mathematics ? Who can start to craft an equation wherein 1,000 boats move 1,000,000 cubic meters of h2o ?

[Thaddeus]

So, given the last couple of posts from Max and Res, can we conclude that this project and the way that it has been implemented has been pointless, or as close to pointless as you can get while looking like there is one.

Plus, it has wasted a large amount of fuel and used resources that would have been much more beneficial elsewhere.

Always look on the bright side. These fools, idiots and other useful people while busy with their very interesting scientific experiment were not in the way obstructing others who were busy helping with sandbags, refugees, handing out food packages, etc., etc.

I always look on the bright side mate (that song is my sign off tune on the radio, it's become more poignant recently)

I have another question for the Chuckle Brothers which will follow shortly.

[Thaddeus]

Question One.

If you were to take every Government appointed individual from Poo Yai up to PM and space then equidistant on the banks of the CP river, what would be the distance between each individual?

Question Two.

If each appointed individual then spoke at length about his/her qualifications/beliefs and plans for the future, would the amount of hot air generated start to evaporate the water? if so, at what rate?

Question Three.

If a couple of members of a forum joined in with similar amounts of hot air, how much effect would it have?

Question four.

If everyone standing on the banks of the CP river at this time were pushed in, how loud would the cheer be?

[rubl]

Question One.

If you were to take every Government appointed individual from Poo Yai up to PM and space then equidistant on the banks of the CP river, what would be the distance between each individual?

Question Two.

If each appointed individual then spoke at length about his/her qualifications/beliefs and plans for the future, would the amount of hot air generated start to evaporate the water? if so, at what rate?

Question Three.

If a couple of members of a forum joined in with similar amounts of hot air, how much effect would it have?

Question four.

If everyone standing on the banks of the CP river at this time were pushed in, how loud would the cheer be?

I assume within Q4 you mean all those government appointed persons as mentioned in Q1/Q2?

Having studied mathematics with some fun stuff like electricity, aerodynamics and some such thrown in, I still have the tendency to only apply things and fill-in normal, real, or imaginary numbers to replace x, y, z when I had a few beers and feel naughty

[cloudhopper]

The physics behind it, as far as I can see, are exactly the same.

That is sadly incorrect.

[MaxYakov]

Question One.

If you were to take every Government appointed individual from Poo Yai up to PM and space then equidistant on the banks of the CP river, what would be the distance between each individual?

Question Two.

If each appointed individual then spoke at length about his/her qualifications/beliefs and plans for the future, would the amount of hot air generated start to evaporate the water? if so, at what rate?

Question Three.

If a couple of members of a forum joined in with similar amounts of hot air, how much effect would it have?

Question four.

If everyone standing on the banks of the CP river at this time were pushed in, how loud would the cheer be?

What is this? Thaddeus' Big Questionnaire Part Deux? Why should I answer these when you couldn't be bothered to answer mine about what values you plugged into my QOPF formula? You're keeping us under very stressful suspense.

Tell you what, why don't you do something useful? Why don't you take some questions and run them over to the river to see and see what kind of answers you get from the Minister's 'water diversion' boat operators:

1) Engine specs.: how many horsepower, type, etc.

2) Nominal engine RPM

3) How many operating hours/day at that RPM

4) Operating hours/day at other RPMs

5) Fuel consumption

6) Propeller diameter/type

7) Hull displacement

8) How obtains fuel, how reimbursed for fuel

9) How operator feels about the project and any particular problems they've had

10) Anything else you can think of that might tells us &lt;deleted&gt; is going on with them.

You know, trivial questions like that. You should be familiar with those by now, doncha think?

In the likely turn-down of this opportunity by Mr. T,, is there anyone else willing to volunteer?

Edited October 24, 2011 by MaxYakov

[Thaddeus]

Question One.

If you were to take every Government appointed individual from Poo Yai up to PM and space then equidistant on the banks of the CP river, what would be the distance between each individual?

Question Two.

If each appointed individual then spoke at length about his/her qualifications/beliefs and plans for the future, would the amount of hot air generated start to evaporate the water? if so, at what rate?

Question Three.

If a couple of members of a forum joined in with similar amounts of hot air, how much effect would it have?

Question four.

If everyone standing on the banks of the CP river at this time were pushed in, how loud would the cheer be?

I assume within Q4 you mean all those government appointed persons as mentioned in Q1/Q2?

Of course.

[MaxYakov]

If you believe no recirculation is going to take place, then we have a lead. Before that let me explain your concern why that velocity is faded away after some some distance. Assuming swept area of cylinder liked velocity that is produced by the propeller is 1m2. The water has exit velocity of 3m/s relative to stationary frame of reference. As it travels away from the stationary propeller the velocity cylinder will drag the surrounding water to move together. The flow model is definitely viscous flow. Not inviscid. As the the water moves further, the surface area of contact with slow moving water will become bigger. Eventually at some distance away, the exit velocity has become very small.

From conservation of momentum, if you can plot average velocity versus distance from the propeller exit point, for two cases namely with the propeller and without the propeller , you can see that the velocity at the same distance from exit point of the propeller will always higher in favor of with the propeller. But then both velocities approaching almost the same value as the distance gets further. Theoretically they never be the same. Otherwise, conservation of momentum is violated. Practically, they looked the same.

Let say after 50 m after propeller exit, there is no significant change in river velocity. What happens if you put another propeller to supply kinetic energy to the moving water at this point? Then another one 50m down stream .... until river mouth? If you believe no recirculation will take place, how you are going to argue that conceptually the flow remains the same? You can see it clearly that the water at that particular stream moves faster then as if the propellers are not there. Next, how about the second series of propellers. The third one... the fourth one. .. You can place all the way across the the river stream. After all you have 1000boats with you.

I think you can still recall the image that illustrated the concept to vent exhaust gasses from a road that you posted a few days ago. The concept works well for a road tunnel. Why the same concept cannot work for a river? The physics behind it, as far as I can see, are exactly the same.

I'm saying that recirculation would be a minimal factor. If we could quantify it, we could deduct it from the ideal's percent energy value.

Your description of propeller exit flow matches the Jet Stream Theory in my previous post, but avoids describing it as a velocity-matching situation where when faster, prop wash water adds momentum in the from of velocity to the slower water. If I may adjust your statement slightly by saying that 'both velocities approaching almost the same, but slightly higher, velocity than the river's previous velocity'. Or some such. If we don't get the acceleration of river water, however slight, this model will fail. As you say, it cannot violate conservation of momentum law, except with the transformation of energy to heat in the velocity-matching process.

Any increase in river velocity from one boat would probably be considered insignificant, but it's only 1/1000 of the available energy. Placement of boats to maximize energy use would be an interesting subject. I would say the boats should be placed in center channel where shore/boundary losses are less and river velocity is greatest. They could be daisy chained from a relatively few mooring points. One problem with this is keeping them in mid-channel. The widening energy dispersal cone could cause undue losses to lower-velocity water, but, hopefully, not due to contacting the shore/boundary layer. Undue stress on the boats might also be problematic especially with the final boats or boats in the daisy chain

Yes, I recall the serially-arranged road vent fans an exact analogy with the river, because there is not an existing stream velocity and the fluid (air and CO) has much less momentum than water. For any distance, the airflow would have to be re-energized to keep it moving at a decent velocity. Still, as you say, I don't see why the boats could not be arranged serially and at certain distance from each other.

If one wanted to test the Water Jet Dispersal model, it would be fairly easy to do. Deeply submerge a garden hose that has been restricted to provide a higher velocity flow (or a 3-4 cm fire hose would be even better) in the center at the deep end of a swimming pool, pointing toward the shallow end. Approach the hose from the shallow end using your body to detect increased water velocity from the hose. You might be able to detect the dispersal velocity degradation as you move away from the hose's axis (left, right).

Or maybe it would just be an opportunity for you neighbor confirm you insanity by seeing you playing with water hoses in a swimming pool (especially if you're using the apartment's 3-4 cm fire hose)

Edited October 24, 2011 by MaxYakov