Changes between Version 36 and Version 37 of WikiStart


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Timestamp:
Sep 13, 2017, 11:28:44 AM (3 years ago)
Author:
steiger5na
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  • WikiStart

    v36 v37  
    170170=  =
    171171= 7 - Diary: =
    172 '''Thursday 07 September'''
    173 
     172== '''7.1 Thursday 07 September''' ==
    174173The 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.
    175174
    176 '''Friday 08 September'''
    177 
     175== '''7.2 Friday 08 September''' ==
    178176To 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.
    179177
    180 '''Monday 11 September'''
    181 
     178== 7.3 Monday 11 September ==
    182179The 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.
    183180
     
    222219When turning to the horizontal cameras it was decided that sloping topography gave too many uncontrolled reflections that made it unsafe to increase the intensity. To remove these,parts of the bathymetry has to be Paint in black. The tank was set to empty during the night, while recycling the water.
    223220
    224 '''12 September'''
    225 
     221== '''7.4 Tuesday 12 September''' ==
    226222The bathymetry has been painted black, a pipe has been introduced into the source and the drain has been lowered to that it can be used also for 60 cm water depth.
    227223
     
    246242We repeated the HS with a reduced time to 200 ms between the photos and and exposure time of 30ms'''. We realized afterwards that the cameras only took every second photo, so with a time interval of 400ms! '''
    247243
    248 '''13 September'''
    249 
     244== '''7.5 Wednesday 13 September''' ==
    250245The cameras are fixed now and taking every photo and the particles are spread out in the ambient water.[[BR]]So, we start the next experiments.
    251246
     
    256251'''Experiment EXP04'''
    257252
    258 We started a new experiment at !10:25 with a reduced flow rate of about $Q = 20 l/min$ (diaphrama diameter of 6.8 mm). The first HS is run for 15 min now. We waited for 5 more minutes until the flow is more established until we start the scan. 
     253We started a new experiment at !10:25 with a reduced flow rate of about $Q = 20 l/min$ (diaphrama diameter of 6.8 mm). The first HS is run for 15 min now. We waited for 5 more minutes until the flow is more established until we start the scan.
    259254
    260255Note: During the scan, the laser is shaking too much! This needs to be changed.
    261256
    262 Observations: The bubble at the source disappeared due to the lower flow rate. The current follows along the slope and turns left at the 2nd curvature into the trough. After the 15 min after the flow was turned on, the flow bifurcates at the continental coast and at the trough and fills up the trough. The return flow does not follow along the upstream slope of the trough, but occurs in the middle of the trough. The main current along the slope is getting wider with time. [[BR]]''''''
     257Observations: The bubble at the source disappeared due to the lower flow rate. The current follows along the slope and turns left at the 2nd curvature into the trough. After the 15 min after the flow was turned on, the flow bifurcates at the continental coast and at the trough and fills up the trough. The return flow does not follow along the upstream slope of the trough, but occurs in the middle of the trough. The main current along the slope is getting wider with time. [[BR]]''''''''''