Ship thrusters to be used in flood drainage

[mettech]

Tell you I have been on deep sea ship and we had thrusters  and it work for  getting away from the wharf but to be plunged into the water it will do like a blinder an it will cavitate that will be something to see in action.

Hope it work because these people are very resilient and they have no choice but to stay close to their home.

[peter267]

What we see all over Thailand - that is pretty unique -  but part of the local  fabric  are the tubular irrigation pumps 4-6m long tube from 6" to 18" diameter  set at angle on a canal bank - this has a single propeller at the base connected by a drive shaft to an engine.  These produce a very high output  to lift water up a low lift/head  to irrigate huge area of fields.  They are adapting to flood relief what 100,000's Thai farmers practice daily.

 

Its just a question of scale - put enough rotating  thrust propellers in a contained - banked or walled khlong/canal river will induce water to flow in one direction.  OK its about emptying huge volume of flood waters lying close to ocean level (minimal pump head - or lift required  - and these conditions are what exist here in Thailand.    Get enough power - sufficient for the purpose - it will move a lot of water very fast down existing channels.

 

Its an easy effect to see if leisure boating in the English waterway system of  the old narrow canals in a line of boats all moving one way in a canal system.  Dog walkers etc will notice a distinct current and flow in what should be a neutral no flow system.   Or if you are mopping out flood water off a flat floor - you will see people just sweeping back wards and forwards in one place  to simply induce the water to flow in one direction off the flat floor 

 

It is easy to measure effect - simply measure the flow of water flowing under gravity into the ocean and then its increase due to the application of the rotating propellers.  A ship thruster will be sized to produce a one way push of so much force =  water thrust  - to move a vessel of so many tons based on the energy being delivered.

 

Sure lots of imponderables on friction over distance, tide and efficency - but this really not such a dumb idea.  Water will be moved.

 

 

 

 

 

 

 

 

[ksamuiguy]

it is a propeller it provides thrust, it is not a pump!

[CGW]

Sure they are going to move "some" water, but the percentage compared to the volume would be negligible! Thrusters would be engineered to produce "torque" not push large volumes of water, reckon this engineering feat is based more on financial gain than good engineering practice?

[boomerangutang]

2 hours ago, fruitman said:

I don't agree.

 

It's sure possible to pump water into a basin which has the same level...If you have a dam with the same level of water at 2 sides and put a row of thrusters on one side it's possible to push water through an opening in the dam. Just make sure it won't flow back at another spot.

 

Just look at the waves behind a longtailboat, it's elevated water..Thrusters are more powerfull and will create higher waves and a strong flow.

 

It sounds like you're referring to a continual high-pressure, high-volume pumping.  It's impractical.  Even if that worked, it would only work, at most, for a few cm in height, and would entail a shitload of power supply.   Any interruptions in power, and the water would flow back to a lower level. 

[elgordo38]

3 hours ago, steven100 said:

hmmm ...  never ever heard of this before ....  hope it works 

 

not sure how because water will either flow to or sit at the lowest point.  

It falls into the same category as cloud seeding. Maybe they overdid the cloud seeding in the south. Some adjustments might be called for. Would be nice to see a government baht for baht scheme where they match any contributions by the public. Scratch that idea we do not want to endanger the submarine money. 

[zaphod reborn]

 

[Redline]

I would love to think this is fake news.  Why just not tell everyone to blow on the water in the direction they want it to go?

[ChrisY1]

Thailand has serious issue moving sewage....let alone moving millions of tons of water!

[jerojero]

Fighting gravity? If the land flooded is higher elevation than the sea, ok ok. But otherwise..

[Reigntax]

4 hours ago, fruitman said:

 

I don't agree.

 

It's sure possible to pump water into a basin which has the same level...If you have a dam with the same level of water at 2 sides and put a row of thrusters on one side it's possible to push water through an opening in the dam. Just make sure it won't flow back at another spot.

 

Just look at the waves behind a longtailboat, it's elevated water..Thrusters are more powerfull and will create higher waves and a strong flow.

 

 

 

Sorry this is a joke. Simple hydrodynamics. You lose 1 velocity head entering a sump. As the mass of water down stream of the thruster is stationary or having next to zero velocity the affect is ziltch unless in a pipe or semi filled culvent.

Edited January 9, 2017 by Reigntax
Typo

[Reigntax]

2 hours ago, peter267 said:

What we see all over Thailand - that is pretty unique -  but part of the local  fabric  are the tubular irrigation pumps 4-6m long tube from 6" to 18" diameter  set at angle on a canal bank - this has a single propeller at the base connected by a drive shaft to an engine.  These produce a very high output  to lift water up a low lift/head  to irrigate huge area of fields.  They are adapting to flood relief what 100,000's Thai farmers practice daily.

 

Its just a question of scale - put enough rotating  thrust propellers in a contained - banked or walled khlong/canal river will induce water to flow in one direction.  OK its about emptying huge volume of flood waters lying close to ocean level (minimal pump head - or lift required  - and these conditions are what exist here in Thailand.    Get enough power - sufficient for the purpose - it will move a lot of water very fast down existing channels.

 

Its an easy effect to see if leisure boating in the English waterway system of  the old narrow canals in a line of boats all moving one way in a canal system.  Dog walkers etc will notice a distinct current and flow in what should be a neutral no flow system.   Or if you are mopping out flood water off a flat floor - you will see people just sweeping back wards and forwards in one place  to simply induce the water to flow in one direction off the flat floor 

 

It is easy to measure effect - simply measure the flow of water flowing under gravity into the ocean and then its increase due to the application of the rotating propellers.  A ship thruster will be sized to produce a one way push of so much force =  water thrust  - to move a vessel of so many tons based on the energy being delivered.

 

Sure lots of imponderables on friction over distance, tide and efficency - but this really not such a dumb idea.  Water will be moved.

 

 

 

 

 

 

 

 

 

The only problem is the water level is higher than the canals therefore the kinetic energy (velocity head) is non directional after the energy is dissapated by outwards flow as distance from the source increases.

[StefanBBK]

Royal Thai Navy: "If only we had a submarine, then we could easily locate the plug and drain all the water! In the meantime we will push..."

Really funny. Thanks Klaus!

[bluebluewater]

I'm in favor of a low powered thrust from time to time.

 

It appears that the Bangkok Yacht Club of 2011 is going to do their bit again in 2017 where those "thrusters"  helped so much.  The Spirit of Plod indeed!

 

My suggestion in 2011 was that everyday citizens be stationed a meter or so apart along the banks of the flooding with boat paddles or tennis rackets and whatever was handy and that everyone paddle in unison and soon that water would be wisked away.

[fruitman]

2 hours ago, Reigntax said:

 

Sorry this is a joke. Simple hydrodynamics. You lose 1 velocity head entering a sump. As the mass of water down stream of the thruster is stationary or having next to zero velocity the affect is ziltch unless in a pipe or semi filled culvent.

 

There are rivers so they flow downstream to lower land. Pushing the water in those rivers will help and the more power pushing it the better it flows downstream. A whole row of thrusters across the river will have some effect.

 

Also it's sure possible to pump water out of lower laying land into sea, the Dutch are experts in it.

 

Thailand needs to invest in a good waterflow system but that discussion has been several times on this forum...so far nothing constructive is done....yes the officials have visited Holland to see how they do it there and the Japanese experts have been in Thailand to teach them...but nothing is built yet.

 

 

[impulse]

5 hours ago, ksamuiguy said:

it is a propeller it provides thrust, it is not a pump!

 

Propeller is another word for axial flow impeller.   Many different designs for specific purposes, but make no mistake, they move water.  They're pumps.

[Thailand]

I believe that during the dry season they can detect explosives so dual purpose.  

[impulse]

2 hours ago, Reigntax said:

The only problem is the water level is higher than the canals therefore the kinetic energy (velocity head) is non directional after the energy is dissapated by outwards flow as distance from the source increases.

 

Velocity is a vector quantity, not a scalar quantity.

[fish monger]

Why not declare specific areas of the country as UNINHABITABLE and be done with it...Ship thrusters....5555 Give me a break...!

[Reigntax]

31 minutes ago, impulse said:

 

Velocity is a vector quantity, not a scalar quantity.

 

Yes, hence magnitude and direction and any type of propeller, jet, thruster due to its geometry, in an open, unconfined situation produces  a proportion of outward discharge or flow uniformly away from the axis when rotated which increases with distance from the point of discharge.

 

Or simply, the velocity profile changes with distance and becomes less directional.

Edited January 9, 2017 by Reigntax
Typo

[boomerangutang]

To give you an idea of Thai engineering prowess:

 

About 15 yrs ago, my town of Chiang Rai decided to build a culvert under some streets to, you guessed it, facilitate flood drainage.  After the first attempt, including re-building the street with asphalt covering, it was found the water didn't drain. The culvert was at a bad angle.

 

A second job was done.  All the 1 km of streets were again torn up, new culverts put in, streets rebuilt and paved.  Yup, you guessed it. It didn't drain.

 

The third attempt worked. 

 

I thought of donating a 2 meter plumb level to the local engineering guys, but then I'd have to explain how to use it.

 

[fruitman]

1 hour ago, fish monger said:

Why not declare specific areas of the country as UNINHABITABLE and be done with it...Ship thrusters....5555 Give me a break...!

 

I also thought it would be these and mounted on a small boat which are on the trucks. But they are huge...

 

Edited January 9, 2017 by fruitman

[ddavidovsky]

9 hours ago, impulse said:

 

Look up "axial flow impeller".  They're used all over the world to move water at a high rate and low delta P.  They add energy to the water in the form of velocity, meaning the water gets to where it's going faster.

 

This is actually a proven concept, and not a bad idea.  Whether it's been properly engineered for the specific application?  I'd have to look at the numbers.

 

Maybe in a river channel but where flood water is dispersed over a wide area (imagine the satellite picture) how are a few 'impellers' going to help? Looks like total bs to me. I wonder how much those things cost the navy...?

[fruitman]

48 minutes ago, ddavidovsky said:

 

Maybe in a river channel but where flood water is dispersed over a wide area (imagine the satellite picture) how are a few 'impellers' going to help? Looks like total bs to me. I wonder how much those things cost the navy...?

 

I assume they will put them in the main riverchannel so the whole waterlevel will lower slowly....in and outside the rivers.

 

It doesn't matter what they cost, it's about keeping the nation together.

Edited January 9, 2017 by fruitman

[whaleboneman]

14 hours ago, mettech said:

Tell you I have been on deep sea ship and we had thrusters  and it work for  getting away from the wharf but to be plunged into the water it will do like a blinder an it will cavitate that will be something to see in action.

Hope it work because these people are very resilient and they have no choice but to stay close to their home.

Just thought I'd let you know that someone has used your photo as the "bargirl killer". I assume it's a mistake. It shows up at the bottom of the page in the photo links.

[gk10002000]

Isn't this the scheme they tried a few  years ago in Bangkok, where they were lining up five or six of these little boats abreast and they thought that would push the water out to the ocean?

[impulse]

8 hours ago, ddavidovsky said:

 

Maybe in a river channel but where flood water is dispersed over a wide area (imagine the satellite picture) how are a few 'impellers' going to help? Looks like total bs to me. I wonder how much those things cost the navy...?

 

The way you get the water out of the fields is to make room for it in the river channels.  The way you do that is to get the water in the river channels out to sea faster.  The way you do that is to increase the velocity (and therefore, the mass flow rate) of that water headed toward the sea.  Axial flow pumps are a widely accepted way to do just that.

[fruitman]

1 hour ago, impulse said:

 

The way you get the water out of the fields is to make room for it in the river channels.  The way you do that is to get the water in the river channels out to sea faster.  The way you do that is to increase the velocity (and therefore, the mass flow rate) of that water headed toward the sea.  Axial flow pumps are a widely accepted way to do just that.

 

Exactly, but that's too complicated for most TV-posters.