Changes between Version 47 and Version 48 of WikiStart

Sep 15, 2017, 5:08:31 PM (3 years ago)



  • WikiStart

    v47 v48  
    270270When scanning dt was set to 100 ms, but only every second photo was aquired so dt= 2 x 100.
    272 '''7.6 Thursday 14 September'''
     272=== '''7.6 Thursday 14 September''' ===
    274274=== Experiment EXP08 ===
    348348=== Experiment EXP14 ===
    349 We increase the influx to a desired value of 80 l/min with still the higher water level and increased rotation rate.
    351 Due to the high flux rate, we use an exposure time of 30 ms.
     349We increase the influx to a desired value of 80 l/min with still the higher water level and increased rotation rate. Due to the leak there are water bubbles at the surface of the water at certain places.
     351Due to the high flux rate, we use an exposure time of 30 ms and a dt of 100ms.
    353353Notes: The water level increased constantly. After this experiment, we had to adjust the sink to let out more water. It takes some time, so we had to wait until the water level was good again.
     355Water level on the screen : 63.4cm. The desired flux rqte was 80L/min, we used the 16mm diaphragm and measured a rate of 94.7L/min.
     357Observations : The flow took 20s to reach the first corner, nothing crosses the shelf, a circulation is created on the shelf by water turning on the 1st or 2nd corner.
     359After a while some part of the current started following the slope after the 2nd corner.
     362=== Experiment EXP15 ===
     363We wait for the water level to decrease (for about 2 hours) and reach 62.7cm on screen.
     365The desired flow rate is 50L/min and with the diaphragm of 12.6mm we measured a flow rate of 52.2L/min.
     367Observations : The flow reaches the first corner very quickly, then turned to the left and circulated on the shelf quite fast. Then a second branch started circulating inside the depression following the bathymetry.
     369After that a third smaller branch started to follow the slope.
     371Note : After this experiment, inertial oscillations appeard and the water started to move so we had to wait until further experiments.
     374=== Experiment EXP16 ===
     375When we started this experiment the inertial oscillations were reduced but not suppressed.
     377The desired flow was 35L/min, with the diaphragm of 10mm we measured 36L/min.
     379Observations : At the first corner a larg part of the flow turned left and went on the shelf, circulating in a larger vein than the previous experiment.
     381Some water reaches the 2nd corner spliting in a major part entering the depression and a smaller and slower part flowing along the slope.
     383There was no recirculation inside the depression, all the flow was evactued at the end of the depression bypassing the "land".
     386=== Experiment EXP17 ===
     388At the beginning of the experiment there were almost no oscillations left.
     390The desired flow was 20L/min, with a diaphragm of 8.2mm we measured 21.6 L/min.
     392Observations : At the 1st corner the flow continued straight ahead. At the 2nd corner the flow splited in 2 branches of equal size, one following the slope and on entering the depression.
     394There was a very clear a very clear and narrow jet following the bathymetry inside the depression, with a lot of meanders on its sides.
     396After a while a branch detached from the slope current at the western corner of the depressionm entered the depression and recirculated joining the eastern side of the depression (drawing on the experiment paper).
     398We wanted to keep the same setup and to inscrease the flow rate to 80L/min in order to have consistency but unfortunately we were running out of time.
    355399  '''' ''6 - Table of Experiments: '''''