SEAVAX - WATER TANK TEST FACILITIES

WATER TANK TESTING FACILITIES FOR SEAVAX and SEANET

 

  BRICKS & MORTAR - FILTRATION - GLASS & PAINT - GANTRY - HYDRODYNAMICS HISTORY - INSTRUMENTS - LABORATORY - LOGISTICS - OUR TEST TANK - SEAVAX TEST VIDEOS - SLUICE GATE - WAVE MAKING - WIND MACHINE

 

Prvate lake for testing the SeaVax Enterprise in private

 

PRIVATE TRIALS - We use secure (controlled) locations to test our vessels in Sussex, in private in the real world. The picture directly above looks for all the world like Lake Dumbleyung in Australia in this light. Lake Dumbleyung is where Donald Campbell set the first of his unbeatable double achievement (land and water world speed records in the same year). Though the location is secure, the conditions are not.

 

 

 

CONTROLLED CONDITIONS - On these pages you can see how we took a near derelict turn of the (last) century site and converted it into our tank test facilities between April and June of 2016. This is a major stage in the development of the SeaVax/RiverVax series of anti-pollution craft.

 

 

Water tanks and testing is hardly mainstream conversation, yet this highly specialized subject is also diverse, with each installation being virtually unique. For this reason we take a look at some of the variations, because we can learn something from every one - otherwise, they would all be the same of course.

 

Most tank testing facilities cost their institutions several million US $dollars or £pounds sterling. We simply do not have that kind of money for design confirmation tests. We pride ourselves on getting a job done as economically and simply as possible. Where the US Navy MASK test tank is probably the largest water basin in the world, it is possible that we are the smallest and most economical tank test facility in the world. We estimate conversion and equipment costs to be around $47,400 (including some shared equipment with the robotics lab).

 

 

 

CHRIS HAS THAT FRIDAY FEELING - On the 29th of July, our proof of concept model made it into the test tank, sucked up plastic and filtered it out, passing clean water back into the tank. our sluice gate worked superbly with just a dribble on the left hand corner. We are fixing that by using more flexible 13mm thin wall silicone tubing. We tried a thick soft rubber hose (18mm) first and then a garden hose pipe (that strangely worked quite well), but the radius in the corners caused a kink that would not come out. Copyright © July 29 2016, all rights reserved. You will need permission from Bluebird Marine Systems Ltd to reproduce these photographs.

 

 

 

 

HYDROCYCLONES - [LEFT] Here we can see the hydrocyclones in action. We scattered plastic fragments onto the surface of our test tank and allowed the SeaVax to trawl slowly for a couple of minutes. You can see the plastic spinning in the twin chambers as water passes through. [RIGHT] Out of the water, we can see the solid plastic waste we have collected at the bottom of the chambers. For legal reasons we cannot reveal more about the processing at this stage. Copyright © July 29 2016, all rights reserved. You will need permission from Bluebird Marine Systems Ltd to reproduce these photographs.

 

 

 

FRIDAY 29th JULY 2016 - Chris Close, watches plastic being sucked into the SeaVax development model. It was a hot day but still the water was cold. That is why we are heating it for our testing programme. Copyright © July 29 2016, all rights reserved. You will need permission from Bluebird Marine Systems Ltd to reproduce these photographs.

 

 

ECONOMICS 

 

What are the savings to the project? By way of example, the Berkeley Wave Tank (circa 1930's), which is basically a long narrow tank designed for pull testing of ship hulls costs about $1500/day to hire. A more modern wave tank costs around $10,000/day. As we will be conducting tests on our robot vessel routinely we would be looking at $300,000 dollars for 30 days of testing in 2016 - that is if we were to go the hire route.

 

 

 

CONSTRUCTION - Putting up the stainless steel beams and uprights is a lot quicker than cutting the beams to size and fabrication. On site welding skills are the essential ingredient - that and a reliable tape measure and a spirit level.

 

 

Why do we need tanks to test out SeaVax when we have two ponds nearby for open water tests?

 

You are right to ask such a question - and yes the SeaVax floats perfectly as you can see from our open water test pictures. The answer though, is that in open water tests, there are many uncontrollable variables, due to the vagaries of nature. Far too many to run a series of tests on a low budget in a short time. On a pond (or even in the sea) we cannot create storm conditions and above on demand. Nor can we measure the forces on the boat as accurately - and recording the data is much harder. Most important of all, we cannot introduce plastic and other waste into a pond full of wildlife.

 

We must though establish some values to compare with the full size SeaVax. We are bound to find out more about the vessel's performance with these tests, that we cannot afford to find out full-size, when modifications become rather expensive. In a controlled environment we can see how effective SeaVax is at filtering out plastic and other contaminants. With a sluice gate for rapid emptying and cleaning, we can be back in business with clean water in a couple of hours.

 

Robotics laboratory and test tank installations

 

DEVELOPMENT FACILITIES - A diagram drawn to scale showing the proposed SeaVax laboratory (left) in relation to the test tank (right). These are in progress improvements to protected facilities that are being undertaken by volunteers as of late March 2016. SeaVax engineers need space to develop the electronics in a lab that is not subject to welding fumes, grinding grit and other dust that general purpose workshops suffer. It will be handy to have a test tank convenient to a robotics lab, that will save time out, transport costs and hire charges for water trials, such as docking and waste clearance performance trials. By making these building modifications ourselves, we will also save the project a shed load of money.

 

 

 

TANK TEST DOCKING - Shown in this diagram is a 1/4 section of a Handymax hull in 1/20th scale as a grey onlong, with our SeaVax proof of concept boat readying itself to dock. At this scale a complete Handymax (PlastiMax) hull would be around 7.7 meters (25ft) long. An overhead gantry will provide facilities to mount both the SeaVax and Handymax hull sections using three-axis mounts and a mix of sensing electronics, simple balances, and heel angle indicators including strain gauges for precise measurements. This view does not include the overhead gantry.

 

 

 

RECIRCULATING MODE - Twin pumps and a vane guide system are inserted into the water tank for hydrodynamic hull evaluations. This makes a closed loop water-chamber that offers a lot of options for experiments for considerably less expenditure. The results are sure to be less accurate compared to the $multi-million dollar installations seen on this page, but we can interpret our results to obtain meaningful data.

 

 

NECESSITY IS THE MOTHER OF INVENTION

 

There are two types of test tank:

 

A. Where the a boat model moves (is towed) through stationary water and

B. Where circulating water moves around a stationary (suspended) model.

 

The largest and most expensive fall into category A. A tow tank, or water testing basin is basically like a long swimming pool, usually with a substantial steel gantry overhead to be able to suspend a model from and propel it across the water. Such a facility usually incorporates wave making facilities.

 

At time of writing (2-4-16) we cannot afford to hire conventional tow tanks for our testing, and we'd make rather a mess of them if we did, because we need to evaluate the mouth of the SeaVax vacuum head for collection performance - and this involves scattering plastic waste on and under the water surface. We also need to perfect our docking system, and that needs to be done before getting anywhere near the final (detail) design stage.

 

 

 

HOW MUCH? - From January to November  of 2015, it cost us £138,000 to go from a clean sheet of paper to get to this stage (above) and attend our first exhibition in London. We can trickle along with our development never showing this or a full size demonstrator in public. But, with the support that has been demonstrated by the recent Avaaz campaign, we feel sure that we can keep up our present development pace, aiming for a the full size prototype, or at least making preparations for build towards the end of this year (2016) for 2017. We have found what we think is a suitable launch site not too far away from our workshops in Sussex. We still need more backing, but are hopeful that there are philanthropic corporations who may be able to top us up as we need it, or who might see this project as a priority for world food security.

 

 

 

 

TESTING, TESTING - An unusual use for a model ship basin, but 'Q' (Jamie) needed to check out the sound and video qualities of the test tank, before water is introduced into the equation. Chris is a qualified public speaker, so welcomed the chance to voice his opinions - in the process helping our techie familiarize himself with this equipment. Copyright © May 15 2016, all rights reserved. You will need permission from Bluebird Marine Systems Ltd to reproduce these photographs.

 

 

WHERE THEN?

 

The next question is where then to test SeaVax? We scouted pools all over Sussex, coming up against mess and clearance issues every time. Plus of course, some of our tests need to be conducted in private because of patent laws prohibiting publication before application in the UK (NOTE: In the USA they have a different system). Maintaining privacy would mean hiring a whole building and barring the owners staff, and that also, would not go down too well. The closest test facilities to us are in London Southampton and Plymouth.

 

The solution is to make a temporary tank at a location where we are permitted to make changes, provided that we restore the situation on completion of our testing programme. We found a suitable area that was difficult to get to, but this problem will be cured with the making of some steps.

 

We can also add water circulating pumps and guides. If we decide that this is beneficial, our tank will become a "circulating tank" and will allow us to calculate hull drag, without needing to tow the hull across a long tank. Well, as you can see we don't have any great length to play with, leaving us with little choice but to improvise.

 

 

 

GROUNDWORKS TIME LAPSE - In this video you can see how we took the base of an old building that had become overgrown and neglected, and removed the flora and accumulated rubbish to enable us to modify the layout for our test tank.

 

 

SEAVAX TANK SPECIFICATIONS

 

With a very limited budget, our shopping list will be curtailed:-

 

1. We need a water tank that is deep enough for our scoop to deploy fully underwater and allow us to film the boat in motion subsurface - while it is scooping up plastic.

 

2. We need to be able to empty and clean the tank quickly to get rid of one type of plastic and try other sizes and formulations. As far a we know this is unique to us.

 

3. We need to be able to cover the tank at night to stop birds and plant debris contaminating our experiments.

 

4. We need overhead and underwater lighting to be able to focus on experiments and capture every detail.

 

5. We need to be able to simulate storm conditions to test vessel stability and safety features, such as solar wing and wind turbine folding/furling - and the effectiveness of floodable compartments as a sea anchor.

 

6. We need to be able to measure forces on the SeaVax scale hull in these conditions, as well as calculating when plastic is collected most efficiently.

 

7. We need to be able to record footage of the SeaVax proof of concept boat in difficult conditions on the surface.

 

8. All of the above has to be achieved at the lowest cost to the project - and the site will have to be returned to an original state once the project is complete. It is to be a temporary installation.

 

 

 

RENDERING & BASE FRAMES - In this time-lapse video we compress up another team building bash, where the final rendering is complete, ready for us to install the repaired timber base frames. The next few videos will show the gantry supports going in and then finally we'll come on to developing the SeaVax proof of concept model. Hopefully, in June of 2016. The build has slightly overrun with some delay in sourcing materials. We made up for this by doing a feasibility study of the AmphiMax™, an amphibious launch platform that will save us a lot of time and money - if we can refine the design and cost it economically.

 

 

 

WATERPROOF LINER - These flexible sheets are available at most garden centers in a wide range of sizes and qualities. With a bit of clever design and landscaping, an unattractive feature can be brought back to life and made into something useful.

 

 

 

RENDERED WATER BASIN - If you have a smooth rendered facing to your tank, you may be tempted not to use an underlay, but it is recommended.

 

 

A 270 meter long tow tankJere A Chase Ocean Engineering Laboratory at the University of New Hampshire

 

WOW! A 270 METER TOW TANK - [LEFT] This is one of the longest tow tanks in the world. We can just begin to wonder at the cost of building such a superb installation. [RIGHT] The Jere A Chase Ocean Engineering Laboratory at the University of New Hampshire. This tank features a wave making machine. These are both examples of research facilities that only academic institutions and big business can afford, costing £millions of pounds to build.

 

 

 

NEAT - The test tank at University College London has glass sides for observation.

 

 

 

MAKING WAVES - Boyan Slat's Ocean Cleanup team began testing the barrier in different water conditions at the Maritime Research Institute Netherlands (MARIN) in October 2015. They were able to simulate extreme wave conditions to see what the ocean array could withstand. The engineering team are hoping to learn some more valuable lessons from the open water test in the North Sea this year. The first fully operational test Coastal Pilot is set to be deployed off the coast of Tsushima Island in Japan in late 2016; it will be anchored to the ocean bed. MARIN, is one of the leading institutes in the world for hydrodynamic research and maritime technology. The services incorporate a unique combination of simulation, model testing, full-scale measurements and training programmes. MARIN provides services to the shipbuilding and offshore industry and governments. Customers include commercial ship builders, fleet owners, naval architects, classification societies, oil and LNG companies and navies all over the world. MARIN, 2, Haagsteeg, 6708 PM, Wageningen, The Netherlands. Phone +31 317 49 39 11, Fax +31 317 49 32 45, E-mail info@marin.nl

 

 

 

ROUGH WEATHER - Over 100mph winds and 30 foot waves crashing over Brighton Marina on the Sussex coast, English Channel. We need to be able to simulate storm conditions in our test tank to be sure that SeaVax can cope as the wind speeds rise. How we are going to achieve this is not yet cast in stone, but we do have a micro-light propeller and some hefty electric motors - so we should be able to whisk up a storm - with a electronic controller to give us variable wind speeds and suitable swivel mountings in a steel frame, to give us directional control. We can then measure the forces on the hull with wings open and folded, using a variety of instruments, to include strain gauges. We can also flood the hulls as per the full size vessel to simulate sea anchors. The other very important feature to explore, is how the wind turbines will cope deployed and fully furled. Brighton Marina is built to handle such gales with ease. Have you noticed that with climate change, storms are a lot more frequent?

 

 

 

STORM KATIE - Over the Easter Bank Holiday period, March 2016, the south of England suffered storm conditions. This coincided with us clearing the site and picking up materials. Even the our tough little Micra would not have survived this tree. See below.

 

 

 

TONKA TOY - It happened to us in a smaller way. Not many cars could take this kind of a bashing and be ready for work the next day. A very large branch (the size of a small tree) was blown down in August 2014, landing on the roof of our little workhorse. At about 2:00 am in the morning, someone heard the commotion and we went out to cut the Nissan free. There was a dent in the roof as evidence of the encounter, but otherwise this incredibly tough little car was unscathed. In 2014 she was not fitted with our custom built roof rack - as she is today in 2016.

 

 

 

PAVING SLABS - Access to the test tank requires the making of steps where there is only a grass hill at the moment. Paving slabs would be ideal for this purpose. These slabs were donated to the cause on Sunday 27th March, but had to be collected from Burgess Hill using a trailer that already needed attention. Although only 26 miles away, the winding country roads made journey times longer - and it was raining (Storm Katie) and blowing a gale while loading and roping up, but we escaped the brunt of the storm. They were not so lucky in Brighton, with 106 mph winds lashing the coast, and a tree crushing the car seen above. 

 

We are making the lab more accessible in wet weather by making steps, where at the moment there is just a grassy slope that gets slippery when it rains and let's not mention the mud. We needed to borrow the MDs car for this run, because none of the project vehicles (with towbars) are insured, MOT'd and taxed as yet (in the UK you must keep untaxed vehicles off-road on a SORN declaration). Our VW bus is fitted with a towbar, but is due for a makeover so that we may attend events later this year, hence is de-commissioned at the moment. The VW will include a custom built rig to display our robot boat on the revolving stand we built last year for Innovate 2015 (also on a shoestring budget), together with video presentations and a PA system to make us a fully functional educational ocean roadshow.

 

 

 

ARCHIVE -  We are using GoPro cameras in waterproof housings, so getting wet will be par for the course. The HERO 4 Black Edition Action Camcorder shoots in 4k Ultra HD 3840 x 2160 footage for true-to-life pictures with razor sharp resolution and high fidelity audio. Our IT expert, Jamie, used this to capture the action in time lapse for a Youtube release in due course.

The GoPro shoots at 30 frames per second for a smooth and realistic motion, ideal to capture every detail of the SeaVax vacuum head. If this is not enough you can increase the frame rate by shooting at 2.7K, allowing you to capture 50 frames per second for beautiful cinematic edits. You even have the option to increase the frame rate to 120 fps when you record at Full HD 1080p for extreme slow motion footage. This will be useful for studying vehicle behaviour and docking in simulated rough conditions.

The GoPro weighs just 110 grams and is waterproof to depths of 40 m, with built-in WiFi and Bluetooth to control the camera remotely. The ultra-wide angle lens is particularly well suited to time-lapse imaging. Capture shots at staggered intervals of 0.5, 1, 2, 5, 10, 30 or 60 seconds to create clips of slow moving events that can lend your filming a professional quality. GoPro is compatible with up to 64 GB microSD cards and has a 2.5 hour battery life. A USB interface means that you can connect the HERO to both PC and Mac computers to upload your files.

 

 

Solar water heating glass tubes

 

SOLAR WATER HEATING - These solar water heaters arrived on Good Friday (25-3-16), donated to the cause by a local benefactor, with our grateful thanks.

 

 

Solar collectors array of 12 tubes feeding into a manifold.

 

ROOF MOUNTING - Here are the same vacuum tubes, now (28-3-16) mounted on the roof of a convenient outbuilding and ready to start supplying heated water to our underground storage tank. Yes, their is a large domed water tank, that just needs lining. The accumulated heat mass can then be used to heat our test tank, or the SeaVax Laboratory as and when needed. A wind turbine mounted on the end of the lab, will generate electricity for our experiments. This is truly a solar powered research facility. Things were blown about a bit on site from Storm Katie, but there was no damage, save to some fencing that was quite old.

 

 

 

FROSTY MORNING - And once again, the same tubes the following morning. You can see the sun coming up over the adjacent fields, but that the tubes are covered in frost. This highlights the importance of a large heat store (sink). We have a large underground tank that is to be used for this purpose. Until the sun rises, all solar operated equipment is simply on standby.

 

 

WATERPROOFING - POND LINING

 

A pond liner is an impermeable geo-membrane used for water retention, including the lining of lakes and garden ponds. Pond liners need to be protected from sharp objects (for example, stones) below the liner and from being punctured by any objects in the water body. A softer underlay can be used as a precaution, even with a relatively smooth deck. Pond liners are manufactured in rolls. Strips of liner can be seamed or welded together on site.

The edge of the pond liner can be rolled over and secured in a trench or we can fixed it to a vertical wall. The vast majority of flexible pond liners available commercially are manufactured of EPDM, butyl rubber or PVC, with EPDM being the most popular at the moment due to cost. The oldest material used for pond liners are made of clay which can be spread and mixed directly into soil to seal a pond. Clay has the longest life span of all pond liners due to its inert mineral composition that can remain stable for thousands of years.

 

SeaVax ships docking to offload haversted plastic waste

OCEAN TRANSFER - In this diagram we see a 180 x 28 meter Handysize bulk carrier (drawn to scale), and five SeaVax ships docking to unload their plastic haul. If one Handymax can handle around 50,000 tons of plastic waste, it would then take 66 SeaVax transfers (in multiples of five as shown) @ 750 tons each, to fill up one cargo ship. A Handymax would cruise between SeaVax fleets, emptying them in sequence, or as requested by the SeaVax vessels themselves - to make a virtual conveyor belt to land. Our testing tank will not be big enough for five SeaVax ships, nor a proportional model of a PlastiMax. We will be using a half size model ship to keep the exercise containable and just one SeaVax boat. The test tank has to be deep enough to allow the bulk carrier to sink to its maximum displacement line.

 

 

How do you transfer bulk cargo at sea?

 

DOCKING PROCEDURE - The docking couplings and method of transfer are not shown or explained here in any detail for legal reasons. Having said that, we can show you the basic principles. The SeaVax and PlastiMax (a converted bulk carrier) on the left are shown together with the hold of the bulk carrier about one third full with the PlastiMax floating high in the water. As the cargo hold fills up with plastic the ship displaces more water and sinks deeper into the seawater. A special coupling and transfer technique is needed to make this work. The same system will work just as effectively when SeaVax is transferring its cargo in harbours, ports and rivers. Read more on this by clicking on the picture.

 

 

     

 

STRAIN GAUGES - A strain gauge (SG) is a device used to measure strain on an object. They are particularly suitable for model hull tank testing as part of an overhead mounting. The most common SG was invented by Edward E. Simmons and Arthur C. Ruge in 1938. This consists of a metal foil in a grid pattern, bonded to a flexible plastic film (polyimide insulator) that reinforces and insulates the foil from the item being measured. Typically, SGs are laser cut for accuracy. You can see a diagram above and a picture of the actual item as supplied by Radio Spares (RS). RS also do a neat amplifier that multiplies a signal (gain) x 1,000. The above assembly costs in the region of £60. You will need an amplifier and PCB + all the resistors and capacitors to assemble the above board, one for each movement to be measured.

 

The gauges (in multiples of four) are attached to the object to be monitored by a suitable adhesive, such as cyanoacrylate and the whole installation coated in epoxy resin. When an electrical wire (conductor) is stretched the decrease in diameter increases electrical resistance, measured in ohms. Conversely, if compressed, the increase in diameter decreases resistance. To increase the effective length of wire being stretched or compressed, a zig-zag pattern of parallel lines is used, producing a larger measurable change in resistance than would be observed with a single straight-line conductive wire - that would in any case be impractical.

 

 

SLUICE GATE

 

A gate that we can lift, that is also see-through, might be an advantage. To fill our testing tank the sluice gate is slotted in place and a rubber sealing ring is inflated. The tank is then filled with water from an onsite water supply. To empty the tank, we will lift the right had sluice gate a small amount, when the water will empty on the other side into a storm drain. We do not need particularly deep water for our tests, reducing the water used, some of which comes from a rainwater collection system nearby.

 

Our sluice gate is constructed of a treated wooden frame with a thick sheet of structural plywood as the barrier. We are looking at incorporating a glass portal in one of the gates as some time in the future.

 

 

 

SLUICE GATE - Here you can see our sluice gate under construction. We've used treated 4" x 2" timbers to make a sturdy frame that is held together with 6" steel pins. April 14 2016. Read more about this by clicking on the picture above.

 

 

 

OVERHEAD VIEWING - To be able to see and so understand what is happening to SeaVax in simulated sea-storm conditions and high winds from above, this bridge has been installed as a convenient observation platform for scientists - and a popular viewing point for visitors. Copyright © January 3 2017, all rights reserved. You will need permission from Bluebird Marine Systems Ltd to reproduce this photograph except for private research and educational use.

 

 

 

 

PLYMOUTH UNIVERSITY

Housed in the new Marine Building at Plymouth University, the Coastal, Ocean And Sediment Transport (COAST) laboratory provides physical model testing with combined waves, currents and wind, offered at scales appropriate for device testing, array testing, environmental modelling and coastal engineering. This is a flexible facility with the capability to generate short and long-crested waves in combination with currents at any relative direction, sediment dynamics, tidal effects and wind. The Ocean Basin is 35m long by 15.5m wide with a moveable floor that allows different operating depths of up to 3m.

 

The Plymouth University Marine Building project is one of the largest most complex wave and current test facilities that Edinburgh Designs has produced. It was designed for both academic and commercial research and is capable of simulating a wide variety of wave and tidal situations. The facility includes four separate tanks: a deep water ocean tank; a shallow water coastal tank, a sediment flume and a tilting flume. All four tanks are equipped with wavemakers and current generators. The ocean tank has a hydraulic moving floor for ease of access and to simulate different ocean conditions.

 

 

 

 

The new £19m Marine Building at Plymouth University is a world-leading hydrodynamics laboratory that provides flexible, state-of-the-art research, testing, work and education facilities for marine study as well as a business innovation centre for marine renewable technology.

Designed by Burwell Deakins Architects, the new facility forms the centrepiece of the South West Marine Energy Park. But its own centrepiece and the source of its pioneering contribution to the world of movable-floor technology are the Coastal Ocean and Sediment Transport (COaST laboratories where scientists and engineers can run tests within simulated wave, wind and current conditions and then model and analyse the data produced.

The laboratories house two innovative concrete water tanks. The smaller upper tank models coastal water conditions and can simulate waves up to 1:200 and 1:100 scale. Sand and sediment can also be added to more accurately replicate coastal conditions. The larger ocean tank can simulate waves up to 1:20 scale and is one of the largest energy wave test sites in the world.

 

 

 

 

The floor itself is a stainless steel frame with a platform comprising GRP panels that sits within the in-situ ocean tank. Though primarily solid, the floor is strategically perforated to allow water to flow through it when it is being raised. The floor is lifted by six hydraulic rams fixed to its underside that lift the platform into its required position. These rams have been procured from North Sea oil rig fabricators and use the same technology that would be used in the underwater oil extraction process. Brushed steel components along the perimeter of the floor glide against runners fixed to the tank wall surfaces and assist the floor lifting operation.

The tank is also ramped at either end and the waves are generated by more than 20 2.7m-high paddles that are hinged to the tank base. This means that wave conditions can still be present while the floor is in motion. Multi-directional deep-sea and surface-water currents can also be produced by customised recirculation ducts and ship propellers installed in the tank. Again, none of these impinge upon the floor-raising process.


Plymouth University Address: Drake Circus Plymouth Devon PL4 8AA United Kingdom. Tel: +44 1752 600600

 

 

 

STUDY - This picture is a great example of why tank testing is so important. You could not see this pattern, let alone study it in detail without the facilities to capture the shot. Such runs can be carried out at different speeds to find the best operating speed for a hull. Alternatively, a hull can be modified to improve performance. 

 

 

KEMPF & REMMERS - UNIVERSITY OF DUISBURG-ESSEN, CIRCULATION TANK 1961

 

In shipbuilding, model tests are still common to assess new and converted ships and to optimise the hull geometry. Unlike in the automotive sector, the design of prototypes in shipbuilding is not economical due to the size of the vessels.

Therefore, together with a scaled model of the ship and the propeller, the required test data is recorded in three main tests. One of these is the resistance test by which the ship’s resistance can be determined. The ship’s resistance is of special importance for the installation of a suitable propelling engine as the completed ship has to achieve a service speed fixed by contract. The characteristics of the propeller can be determined by means of an open-water test and the ship-propeller interaction can be investigated with the so-called propulsion test. In this test the thrust and torque values are recorded.

 

 

Institute of ship technology

 

UNDER TOW - This model hull glides through the water under tow at the Institute of Ship Technology.

 

 

 

LANCASTER UNIVERSITY - Another approach is to construct a tank in steel sections and bolt it together. We like the glass viewing ports in this unit.

 

 

http://www.umd.edu/

 

MARYLAND UNIVERSITY - The Jones Laboratory is an experimental aerodynamics laboratory in the Department of Aerospace Engineering at the University of Maryland. Their research focuses on unsteady, separated, and three-dimensional flows on flapping wings, 
rotorcraft, and wind/water turbines. They perform experiments in water tanks and wind tunnels to better understand the flow physics and vortex dynamics of these flows. University of Maryland, College Park, MD 20742, USA / Phone 301.405.1000

 

TOWING TANK - A new 1.5m x 1.2m x 7m towing tank with a 4-axis motion control system (pitch, plunge, translation, and rotation) has been designed and constructed under a DURIP sponsored by AFOSR. The tank is also equipped with a set of 33 gust generators to produce an unsteady flow field for experiments on gust encounters. Multiple ATI submergible Force/Torque sensors are used for 6 degree-of-freedom, comprising of Nano25s and Mini40s.

DURIP - Defense University Research Instrumentation Program (DURIP) is administered through the US Air Force Office of Scientific Research, the US Army Research Office, and the Office of Naval Research. The DURIP program is for the acquisition of major equipment by U.S institutions of higher education to augment current or develop new research capabilities to support research in technical areas of interest to the DoD. DURIP is only open to U.S. institutions of higher education, offering degree programs in science, math, and/or engineering.

 

 

 

ALBERTA UNIVERSITY - Coanda was contracted by the University of Alberta to design and build a Stratified Towing Tank. This piece of experimental equipment is designed to provide the capability of studying the characteristics and effects of towing models through fluids that contain stratified layers of different densities. One of the features of this design is a system that provides the flexibility to fill the tow tank with distinct layers of different density fluids or a density gradient. Some other features include a movable interior partition that allows the channel length to be shortened and a computer controlled towing mechanism. Tow Tank Specifications: Length: 8m, Width: 0.8m, Depth 1m. Towing Capability 25kg at 0.5m/s

 

 

Qinetiq naval systems hull testing marine hydrodynamics technology

 

ROYAL NAVY - Qinetiq's tow tank is used to develop naval marine systems, here seen testing the hydrodynamics of a fairly conventional hull - in the process making this stunning picture. MOD funding budgets are copious and continuous, allowing their subcontractors to operate such expansive facilities almost free of commercial risk.

 

 

https://www.rivallab.com/facilities/

 

OTTER - The new Optical Towing Tank for Energetics Research (OTTER). With a cross-section of 1m x 1m and an overall length of 15m, the high-speed traverse system is able to hit Reynolds numbers on the order of a million. The ceiling is sealed to prevent free-surface effects (sloshing) but free-surface testing can be accommodated by lowering the waterline slightly. Optical measurement techniques such as time-resolved PIV and 4D-PTV are employed for direct flow measurements. An ATI Nano submersible six-component balance is used for direct force and moment measurements.

 

 

The Institute of Ship Technology and Ocean Engineering maintains a test facility of its own, enabling the students to gain an insight into model testing and the assessment of ship and propeller geometry.

Measuring section: 6000x1500x750mm (variable water depth up to 150mm)
Maximum fluid velocity: 2 m/s max.
Model sizes: 300–2000mm

The test data is recorded mainly mechanically by means of suitable measuring scales. Fluid velocities can be recorded mechanically as well as via a laser-doppler anemometer. At the institute, the circulation tank is used in teaching. The advantage of the traditional measuring technology is that additional effects like the added resistance due to flat water can be demonstrated very efficiently. 

 

University of Duisburg-Essen
Institute of Ship Technology, Ocean Engineering and Transport Systems 
47048 Duisburg, Germany
Phone: +49 (0)203/379-1173 
Fax: +49 (0)203/379-2779

 

 

US Navy MASK submarine tank testing facilities

 

MASK US NAVY UPGRADE - In 2007 Edinburgh Designs were awarded the contract to upgrade the Maneuvering And Sea Keeping (MASK) basin, the worlds largest wave test facility, for the US Navy. The original pneumatic wavemakers from the 1950s were replaced with 216 flap wavemakers which will provide more accurate wave generation and greatly reduce the amount of calibration users must perform to create the desired wave conditions. The installation was completed in December 2013. In the first six months of operation the machine clocked up over 600 hours of wave generation time. Imagine the energy bill for that!

 

 

 

 

NEWCASTLE UNIVERSITY - COMBINED WIND, WAVE & CURRENT TANK (WWC)

 

This combined Wind/Wave and Current Tank is one of only a handful of such facilities in the world, and was designed for use with any, or all, of the components with equal emphasis.

The Wind Wave Current Tank was designed with small scale model testing for renewable energy devices in mind. However, it is also suitable for standard resistance, sea keeping and wind loading tests experiments.

 

 

 

 

WWC SPECIFICATIONS

Flume length 11 m
Width 1.8 m
Normal water depth 1 m
Air clearance 1 m
Central measurement section 3 m
Maximum water velocity 1 m/s
Maximum wind velocity 20 m/s
Period range 0.8 - 4sec
Wave height 0.02 - 0.2m (period dependent)

For further information, contact: Peter Bowes (Facilities Manager)
Telephone +44 (0)191 208 6919
E-mail: peter.bowes@ncl.ac.uk

 

 

 

 

EDINBURGH DESIGNS - TIDAL WIND & FLOW TANKS

Edinburgh Designs design a variety of hydrodynamic test tanks that combine flow, waves and wind. We have designed and installed ducted propellers within flume tanks, and wide tanks. Their largest tank so far was for the Edinburgh University flow tank with a capacity of 28m³/s. ED desings specialize in designing and commissioning equipment to meet customers specifications.

WIND WAVE & CURRENT TANKS - The University of Newcastle required a wind tunnel above the working zone of a water wave tank. The tank was designed for testing renewable prototypes, although it can also be used for standard resistance, sea keeping and wind loading experiments.

 

 

 

 

WATER CIRCULATING TANKS - Flow tanks are used to test static models in moving water typical applications include ships, marine structures and turbines. The flow propulsion system and return pipe work is specifically designed to match the flow conditions in the working zone. Sizes constructed so far range from 0.6 x 0.6 x 8m to 0.8 x 0.8 x 2m with a flow speed of 2m/s although other sizes are also possible.

 

Edinburgh Designs Ltd
27 Ratcliffe Terrace
Edinburgh, EH9 1SX
United Kingdom
+44 (0) 131 662 4748
info@edesign.co.uk

http://www.mcceexpo.co.uk/about/

 

 

 

PHYSICS - The National Physical Laboratory (NPL) opened its first ship tank on 5 July 1911. It was 150 m by 9 m wide and held 5000 tonnes of water with a centre depth of 3.75 m. A marine engineer and shipbuilder, Alfred Yarrow, provided £20,000 for the tank's construction to enable the testing of ship models.

It was originally known as 'The National Experimental Tank'; later the 'William Froude National Tank' after the engineer and naval architect; and finally 'No 1 Tank'.

The work of the Ship Division was broadly divided into two: investigations commissioned by shipbuilders, ship owners and other external organisations; and the Division's own programme of research.

Commissioned investigations were mostly design studies for new ships and unusual hydrodynamic problems related to existing ships; while the result of the Division's programme of research led to improvements in ship design.

The ship models were made of paraffin wax, first moulded to approximately the form required, and then shaped by a special cutting machine to reproduce exactly the lines of the ship. The use of wax not only enabled the quick and rapid construction of the ship but also allowed the form to be altered to test the effect of modifications.

The tanks included apparatus for producing 1 m high waves so that models could be tested in rough or shallow water.

As a result of increasing demands from industry, the Government provided funds for the construction of a second tank, which was completed in 1932. The record number of models tested at NPL in any one year was 190 in 1944.

A water tunnel (pictured below) to test propeller designs for cavitation (the formation of bubbles by a propeller in water) was provided by Sir James Lithgow in 1938.

 

 

The Emerald bulk carrier, Lloyds and Bestway Marine Engineering

 

TANK TESTING - This is an example of a tow tank, where the model of a ship hull is being tested for hydrodynamic drag and wave keeping performance. Most testing in tanks is to help designers to make hulls that are more efficient to reduce fuel bills. Our main aim is to ensure that a robot boat can couple with a converted bulk carrier. But before that, we need to be sure that our giant vacuum head can suck up plastic particles and filter them out to eject clean water back into the sea. It has worked in test rigs, but we need to be sure that it works well as an assembly.

 

 

Qinetiq's test tank at Haslar

 

UK NAVY - Qinetiq's test tank at Haslar is used to develop nuclear submarines and other naval warships. How can any country justify such expenditure when the oceans are so dirty? Keeping you house in order is sustainable good practice, going to war is a negative for the human race.

 

 

 

 

 

 

LINKS & REFERENCE

 

https://avaaz.org/

https://www.uni-due.de/IST/ismt_circulation_tank.shtml

http://www.edesign.co.uk/portfolio/plymouth/

https://www.plymouth.ac.uk/research/institutes/marine-institute/coast-laboratory

https://www.rivallab.com/facilities/

http://www.npl.co.uk/about/history/research/ship-tanks/

http://www.umd.edu/

http://www.building.co.uk/making-waves-plymouth-marine-laboratory/5069697.article

info@marin.nl

http://www.marin.nl/

https://en.wikipedia.org/wiki/Maritime_Research_Institute_Netherlands

https://www.coanda.ca/services/equipment/tow-tank/

http://www.designindaba.com/articles/creative-work/award-winning-ocean-cleanup-team-launch-their-first-open-water-test

http://www.bbc.co.uk/news/uk-england-35909651

http://stamco.co.uk/

 

 

Recirculating test tank drag testing diagram

 

PLAN VIEW - In this diagram we are looking through the glass roof into the the SeaVax test tank from above. We can see the overhead gantry, carriage and rails positioned so that the model is central in a (dual) converging continuously re-circulating flow of water.

 

 

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