Changes between Version 21 and Version 22 of WikiStart


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Timestamp:
Sep 11, 2017, 2:40:50 PM (3 years ago)
Author:
steiger5na
Comment:

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  • WikiStart

    v21 v22  
    115115The images are divided into the two different cameras as PCO1/ and PCO2/.
    116116
    117 ''[[Image(Topography_with_PositionCameras.png, 300px)]]''
     117''[[Image(Topography_with_PositionCameras.png, 900px)]]''
    118118
    119119''This sketch shows the topography together with the view of the two cameras.''
     
    150150=  =
    151151= 7 - Diary: =
     152'''Thursday 07 September'''
     153
     154The cameras still have to be adjusted. After that is done, we take photos with the calibration grid in the horizontal and in 3D with both cameras that are fixed on the roof. With PIV, we conduct the calibration of both cameras as described in 4.1.
     155
     156'''Friday 08 September'''
     157
     158To verify the calibration, we took photos with both cameras with one ruler to see if the calibrations of the cameras agree (which it does!). Then, we added a wall into the tank to prevent the water of the freshwater experiments to return to the source. The laser height was adjusted.
     159
    152160'''Monday 11 September'''
     161
     162The table starts rotating for the first time with a velocity of 50 rounds/ sec. It gets slowly filled with water to a level of 60 cm. This takes about 3h. Before we can start the experiments, the lasers first have to be adjusted. To check how long the water stays in the water, we conduct a little experiments with water (from the tank) that is enriched with particles. After about 2 hours a 4 mm thick clear surface layer develops.
    153163
    154164''First day of experiment ! We have many difficulties to get an homogeneous distribution of particles at the level of the laser sheet (located in the dense lower layer). We first spray at the surface the particles (30 microns, 1013 g/l) diluted with quite dense salty water. But after waiting one hour the particles never reach the level of the laser sheet... Hence, in order to be able to visualize something we started to inject directly inside the lower layer with the sprayer. We then succeed to disperse high concentration of particles at the level of the laser sheet.''