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Curved Tank

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The Curved Tank was finished in June 2002. We built the new beaches during the spring of 2003. Here's my favourite picture of the new tank with the new beaches and was taken during December 2003. I got this nice glossy effect by combining many digital images - each taken with a hand-held flah in a different place. Click on the photo to get a larger version. We're also have a webcam if you want to see what's happening there right now.

The curved tank is a replacement for our much-loved Wide Tank of 1977 which was the first multi-directional wave tank that was suitable for testing crest-spanning wave energy devices.

If you'd like to know more about the tank, ` papers that that you can read in 'pdf' format:

Paper from the 5th European Wave Power Conference which was held in Cork, Ireland during September 2003: The Edinburgh Curved Tank. This paper describes the new tank in the historical context of earlier Edinburgh tanks and the development of the absorbing wavemaker. It also looks forward to a future 'circular tank' with combined waves and currents.

Final short report with drawings and photos to the EPSRC (the UK's Engineering and Physical Sciences Research Council) who financed the construction: Relocation of a Multidirectional Mixed Wave Spectrum Test-Tank with Modifications for Reduced Area and Minimum Cross-wave Errors

 

Curved Tank - Construction diary (in reverse time order)

28th June 2002. The new curved tank made its first waves this week! Here's a photo sequence taken over the last few months showing some details. If you click on any of the images you'll get a bigger picture.

The tank is financed by the Engineering and Physical Science Research Council and has been built by our spin-off company Edinburgh Designs Ltd..

The tank is designed principally for work with models of 'solo' wave energy devices. However, once a planned rotating towing arm is installed, we hope to also study tidal current turbines.

The space available for the tank was very limited in the 'fetch' direction, but the curved paddle array should give outstanding representations of waves from a wide directional spread. It should also be possible to make 'extreme' waves of greater height than in our old wide tank.

The large glass window will give researchers the kind of intimacy that is essential for optimising wave energy devices. However, at times its wave reflections will have to be controlled by placing additional beaches in front.

Test tanks precise enough for wave energy work were made possible by the development of the 'absorbing' wave maker at Edinburgh in the early 1970s. These wave makers act as beaches even while they make waves. In the curved tank, their ability to rapidly calm down the water surface after the finish of a wave sequence is more apparent than ever.

         
28th June 2002
 

Stephen Salter, Derek Jardine, Penelope Parkin and Win Rampen admire the first 'sneak' wave of the new curved tank. Our initial impressions of the tank are very positive. It feels as if it will be a worthy successor to our 'wide tank' which we dismantled 10 months ago.

The beaches on the left are our old 'Expamet' ones from the wide tank, but we plan new ones made from 'reticulated' foam.

         
28th June 2002
 

The sneak wave was a favourite in the wide tank. An entire directional spectrum is focussed on a specified XY point in the tank and breaks at the specified time.

The computer seen here is from the wide tank. Doug Rogers only needed to update the 'configuration' file of his wavemaking software with the new wavemaker coordinates and angles. After recompiling, we saw our favourite waves again, but this time coming out of the curved line of wavemakers.

       
May 2002
    Edinburgh Designs installing the wavemakers. The curved tank uses 48 of these. They're from the wide tank. The amplifiers are already in position on the platform above. The yellow nylon / polyurethane 'gusset' or 'membrane' is in place. It keeps the backs of the paddles dry.
       
April 2002
    The day after the spraying of the waterproof polyurethane lining by John Metcalfe Ltd . Our old wide tank initially had a fitted terylene / polyurethane lining. We later installed a glass fibre lining.
       
March 2002
    A lone wavemaker paddle rests against the galvanised steel 'piano' units. The curved beam and the motors are in place. The beam curve is of a smaller radius than the wavemaker curve. We plan to later fit a rotating towing arm, the free end of which will nearly kiss the curved beam.
       
March 2002
   

Matthew Rea's piano units have just been installed, the curved beam is on the floor. Each of the 8 pianos holds 6 wavemakers. The angle between wavemakers is 2.5 degrees.

Why have a curved line of wavemakers?
a. Avoidance of parallel tank walls reduces hard-to-damp seiches.
b. Great for multi-directional wave spread and extra power for focussed waves

         
February 2002
    The shuttering is still in place for the truncated concrete wall which will support the extra large glass window. Being able to easily see underwater is very important for wave energy research.
         
February 2002
    Simon Owen at left installing the concrete modules that will form the south wall of the tank. All four walls of the wide tank were made from such modules.
         
November 2001
    The old laboratory nearly cleared out. We were fortunate to be able to use an existing laboratory which is near to our offices. The tank and its activity will be highly visible to students and visitors. There is very good daylight from a lot of windows. This is good for morale but it may encourage too much biology in the water and complicate photography. We will install roller or venetian blinds.