# Changes between Version 85 and Version 86 of WikiStart

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Jan 30, 2020, 3:59:20 PM (7 months ago)
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 v85 = 2 - Experimental setup: = == 2.1 General description == The two Barriers - the shelf break and the ice shelf front - will be studied in two separate sets of Experiments. The two Barriers - the shelf break and the ice shelf front - will be studied in two separate sets of Experiments: '''Part I: Shelf break experiments''' By definition we will use Ox and Oy axis to define the along slope and the cross slope axis. The central reference point (0,0) along the slope is chosen to be the first "land" corner downstream of the source. Positive u - direction corresponds to the along slope flow direction, while positive  v - direction is directed onshelf. The position of the topography relative to this coordinate system is shown in 2.2.1 == 2.3.2 Reference axis for ice front experiments == === 2.3.2 Reference axis for ice front experiments === By definition we will use Ox and Oy axis to define the along channel and cross channel axis. The central reference point (0,0) is chosen to be at the front of the ice shelf and in the middle of the channel. Positive u - direction corresponds to the flow direction towards the ice shelf and positive v - direction is directed to the "west". By definition we will use Ox and Oy axis to define the along shore and the cross shore axis. The central reference point (0,0) along the wall is chosen to be the closest point to the center of the tank. Positive direction corresponds to the mean wave or the mean flow direction. __''We measure the water level at the wall and in the center of the tank to quantify the impact of the free surface deformation.'' We also measure the height of the horizontal laser to determine the possible vertical deviation of the laser sheet???''__ We measure the water level at the wall and in the center of the tank to quantify the impact of the free surface deformation. We also measure the height of the horizontal laser to determine the possible vertical deviation of the laser sheet. ''[[Image(DSC_0811_00001.jpg)]]'' == 2.5 Parameters for Shelf Break Experiments == == 2.5.1 Fixed Parameters == ||'''Notation'''||'''Definition'''||'''Values'''||'''Remarks'''|| ||$H_{shelf}$||Shelf height||$0.5\ m$|||| ||$H_{through}$||Trough height||$0.42\ m$|||| ||$W_{trough-slope}$||Width of slope in trough||m|||| ||$s$||slope||!1:2(Height:Width)|||| ||$\nu$||Viscosity||$10^-^6m^2s^-^1$ ^|||| ||$L$||Total length of the wall||$\ m$|||| ||$W_{Source}$||Width of source (inner)||$23\ cm$|||| ||$H_{shelf}$||Shelf height||0.5 m|||| ||$H_{through}$||Trough height||0.42 m|||| ||$W_{trough-slope}$||Width of slope in trough||10 cm|||| ||$s$||slope in trough||!1:2(Height:Width)|||| ||$\nu$||Viscosity||10^-6^ m^2 ^s^-1^|||| ||$L$||Total length of the wall||3 m|||| ||$W_{Source}$||Width of source (inner)||23 cm|||| == 2.5.2 Variable Parameters == ||'''Notation'''||'''Definition'''||'''Unit'''||'''Initial Estimated Values'''||'''Remarks'''|| ||$T_{rotation}$||Rotation period||$s$||50, 30|| || ||$H_{water}$||Total water depth||$cm$||60 - 70||At the point where waterlevel is not influenced by rotation: r=?? m.|| ||$H_{shelf}$||Depth on shelf||$cm$||10 - 20||estimated where?|| ||$R_c$||Radius of curvature||$m$||0 - 0.5|||| ||$Q$||Flux||$L min{-1}$||20 - ??- ?? - 135|||| ||$\Delta \rho$||Density difference (ambient - inflow)||$kg$||0 - 3 - 10|||| ||$T_{rotation}$||Rotation period||s||30, 50|||| ||$H_{water}$||Total water depth||cm||60 - 70|||| ||$H_{shelf}$||Depth on shelf||cm||10 - 20|||| ||$R_c$||Radius of curvature||m||0 - 0.5|||| ||$Q$||Flux||L min^-1^||5, 10, 20, 35, 50, 80, 110, 150|||| ||$\Delta \rho$||Density difference (ambient - inflow)||kg m^-1^||0, 3, 5, 10|||| == 2.6 Parameters for Shelf Break Experiments == == 2.6.1 Fixed Parameters == ||'''Notation'''||'''Definition'''||'''Values'''||'''Remarks'''|| ||$L$||Channel lengthh||5 m|||| ||$W$||Channel width||1 m|||| ||$H$||Channel height||0.5 m||depth of channel center to flanks|| ||$\alpha$||Slope of channel walls||45^o^|||| ||$\beta$||Slope of channel||1.15^o^|||| ||$H_{iceshelf}$||Ice Shelf thickness||0.4 m|||| ||$\nu$||Viscosity||10^-6^ m^2 ^s^-1 ^|||| ||$W_{Source}$||Width of source (inner)||23 cm|||| ||$H_{water}$||Total water depth||90 cm|||||| == 2.6.2 Variable Parameters == ||'''Notation'''||'''Definition'''||'''Unit'''||'''Initial Estimated Values'''||'''Remarks'''|| ||$T_{rotation}$||Rotation period||s||30, 60|||| ||$dH_{iceshelf}$||ice shelf draft||cm||0, 5, 10, 15, 20, 30, 30-0, 15-0||30(15)-0 means tilted ice shelf|| ||$Q$||flow rate||L min^-1^||15,30,50,60|||| ||$\Delta \rho$||Density difference (ambient - inflow)||kg m^-1^||0,1,2|||| == 2.7 Definition of the relevant non-dimensional numbers == '''Conductivity Sondes (CS)''' '''Particle Imaging Velocimetry (PIV)''' A Spectra-Physics Millennia ProS 6W YAG continuous laser (532 nm) in conjunction with 2 cameras was used to provide PIV images. The laser light sheet was brought in parallel to the bottom of the tank in case of the slope front experiments and tilted by 2% to match the slope of the channel in case of the ice front experiments. The light sheet can then be racked in the vertical through a series of steps through the use of a motorized traverse and a mirror set at 45 degrees. The laser has another set of optics to point the light sheet down at the mirror, producing the light sheet. The laser light sheet positions are then synchronized with the PIV cameras. The laser light sheets cover the whole topography, but are slighlty bended towards the sides, so that they are closer to the bottom at the source and at the end of the topography compared to the middle. Also a vertical laser was used together with a vertical camera to observe the flow in a cross section. The three PIV cameras consist of: '''Particle Imaging Velocimetry (PIV)''' A Spectra-Physics Millennia ProS 6W YAG continuous laser (532 nm) in conjunction with 2 cameras was used to provide PIV images. The laser light sheet was brought in parallel to the bottom of the tank in case of the slope front experiments and tilted by 2% to match the slope of the channel in case of the ice front experiments. The light sheet can then be racked in the vertical through a series of steps through the use of a motorized traverse and a mirror set at 45 degrees. The laser has another set of optics to point the light sheet down at the mirror, producing the light sheet. The laser light sheet positions are then synchronized with the PIV cameras. The laser light sheets cover the whole topography, but are slighlty bended towards the sides, so that they are closer to the bottom at the source and at the end of the topography compared to the middle. Also a vertical laser was used together with a vertical camera to observe the flow in a cross section. The three PIV cameras consist of: - one Falcon1 camera ''(Falcon 4M, CMOS 2432*1728 pixels, 10 bits)'' as the vertical camera – with a 35 mm objective lens.[[BR]] During horizontal PIV, the vertical camera was turned on (with the same acquisition as the PCO1 and PCO2) to produce an .xml file that contains information on the time, dt, exposure time, times for the scanning. During some experiments, this .xml file was missing (technical mistake or if we stopped the acquisition before it was done), so that .xml files from other experiments have to be used and modified to fit the setup. However, the starting time is not correct then. = 4 - Methods of calibration and data Processing = The PIV data will be processed using the MATLAB tool UVMAT available  on !http://servforge.legi.grenoble-inp.fr/projects/soft-uvmat. All  images from the experiments will be stored in the directory  /fsnet/projects/coriolis/2017/17ICESHELF/DATA under the name for the  experiment. == 4.1 Calibration for shelf break experiments == The images for PIV (PC01, PC02) are calibrated from images of a horizontal grid, in 3D with an inclined grid (tilted angles) and in the vertical for the camera fixed on the tank wall.[[BR]]The calibrated images with the grids are stored in 0_REF_FILES/CALIB1 with the [[BR]]- 2D calibration in the directory CALIB_07_09[[BR]]- 3D calibration in the directory CALIB_07_09_3D[[BR]]- Vertical calibration in the directory CALIB_VERTICAL_08-09 ''[[Image(Bathymetry_with_PositionCameras.png, 900px)]]'' ''This sketch shows the topography together with the view of the two cameras.'' ''This sketch shows the topography of shelf break together with the view of the two cameras.'' The  3D calibration is done with the geometric calibration function on UVMAT  to create 'intrinsic parameters' for each camera that will be used for  all images. Calibration points along the inclined grid are marked and  translated from image coordinates to physical coordinates defined in  section 2.3.1 to later take into account the different height of slices. See http://servforge.legi.grenoble-inp.fr/projects/soft-uvmat/wiki/UvmatHelp#GeometryCalib  for details of the method. The calibration parameters are copied in a  xml file beside the folders of each camera (for instance PCO2.xml for  PCO2/). The xml files also containing all the timing information and  have to be copied next to the folders of all images, to use the same  intrinsic calibration data for each image taken with the corresponding  camera. ''[[Image(Channel_with_CameraPositions.png, 900px)]]'' ''This sketch shows the topography together with the view of the two cameras.'' ''This sketch shows the topography of ice shelf together with the view of the two cameras.'' The   3D calibration is done with the geometric calibration function on  UVMAT  to create 'intrinsic parameters' for each camera that will be  used for  all images. Calibration points along the inclined grid are  marked and  translated from image coordinates to physical coordinates  defined in  section 2.3.1 to later take into account the different  height of slices. See http://servforge.legi.grenoble-inp.fr/projects/soft-uvmat/wiki/UvmatHelp#GeometryCalib   for details of the method. The calibration parameters are copied in a   xml file beside the folders of each camera (for instance PCO2.xml for   PCO2/). The xml files also containing all the timing information and   have to be copied next to the folders of all images, to use the same   intrinsic calibration data for each image taken with the corresponding   camera. ||850||85 cm|| ''[[Image(Conversion_MotorLevel_LaserSheet.png, 400px)]]'' An excel sheet to calculate all heights is saved in 0_DOCS/Ice_Shelf_docs.'''''''''' ''[[Image(Conversion_MotorLevel_LaserSheet.png, 400px)]]'' '''''''''' === Probes calibration === ''The laser for the vertical slices is turned on and off outside the wall, where the laser is located. Press the button in the lower right corner of the instrument in the photo.'' == 5.2 How to process the data == Note: At the beginning of the experiment, the water was not completely at steady-state in the trough. The scans were supposed to do 550 images, but only took 500. And it only did 10 levels, instead of 11, so the last level is missing! = 8 - Table of Experiments: = * will be updated from Excel sheet! = 8 - Table with Shelf Break experiments = * Mesurements and more detailed comments on experiments are saved in folder 0_DOCS. ||'''''Exp No.'''''||'''''Name'''''||'''''Valve opened'''''||'''''$H_{water}$'''''||'''''$T_{rot}$'''''||'''''$Q$'''''||'''''$R_{curvature}$'''''||'''''$\Delta \rho$'''''||'''''Diaphragme'''''||''''' Flowrate estimated'''''||''''' Type of photo'''''||'''''Height of HS'''''||'''''Heights of Scan and #'''''||'''''Time photo'''''||''''' Dye'''''||'''''Comments'''''||''' Notes'''|| ||4||exp04||13092017||||50||||0.50||0||6.8||||HS,Scan||||||200ms||no||Laser started vibrating for the scans||Elin|| = 9 - Parameter table with Ice Shelf Experiments = =  = =  = =  = =  = ||EXP||Date||T (s)||Q (l/min)||Corner||dRho (kg/m³)|| ||1||20170912 !14:38||50||50||no||0|| ||2||20170912 !17:02||50||50||no||0|| ||3||20170913 !08:53||50||50||no||0|| ||4||20170913 !10:31||50||20||no||0|| ||5||20170913 !14:02||50||80||no||0|| ||6||20170913 !17:55||50||80||yes||0|| ||7||20170913 !17:55||50||50||yes||0|| ||8||20170914 !09:23||50||20||yes||0|| ||9||20170914 !10:38||50||10||no||0|| ||10||20170914 !11:35||50||35||no||0|| ||11||20170914 !14:27||50||33||no||0|| ||12||20170914 !17:15||50||33||yes||0|| ||13||20170915 !09:16||30||50||yes||0|| ||14||20170915 !10:33||30||80||yes||0|| ||15||20170915 !13:12||30||50||no||0|| ||16||20170915 !15:11||30||35||no||0|| ||17||20170915 !16:02||30||20||no||0|| ||18||20170919 !11:31||50||50||no||0|| ||19||20170919 !14:13||50||80||no||0|| ||20||20170919 !15:08||50||80||no||0|| ||21||20170919 !15:47||50||110||no||0|| ||22||20170919 !16:45||50||110||yes||0|| ||23||20170920 !08:13||50||80||yes||0|| ||24||20170920 !10:08||50||150||yes||0|| ||25||20170920 !11:12||50||80||yes||0|| ||26||20170920 !14:01||50||50||yes||0|| ||27||20170920 !14:40||50||50||no||0|| ||28||20170920 !16:14||50||80||no||0|| ||29||20170922 !09:43||50||20||yes||10|| ||30||20170922 !11:06||50||50||yes||10|| ||31||20170922 !14:30||50||80||yes||10|| ||32||20170922 !15:16||50||50||no||10|| ||33||20170922 !16:05||50||20||no||0|| ||34||20170925 !09:34||50||20||no||5|| ||35||20170925 !10:30||50||50||mo||5|| ||36||20170925 !11:38||50||80||no||5|| ||37||20170925 !14:51||50||20||yes||5|| ||38||20170925 !15:11||50||80||yes||5|| ||39||20170925 !16:53||50||110||yes||5|| ||40||20170926 !9:38||30||20||no||5|| ||41||20170926 !10:22||30||50||no||5|| ||42||20170926 !11:37||30||10||no||5|| ||43||20170926 !14:22||30||5||no||5|| ||44||20170926 !15:32||30||5||no||5|| ||45||20170926 !16:43||30||20||yes||5|| ||46||20170927 !9:00||30||5||yes||5|| ||47||20170927 !10:32||30||50||yes||5|| ||48||20170927 !14:01||30||5||no||3|| ||49||20170927 !14:47||30||20||no||3|| ||50||20170927 !16:05||30||50||no||3|| ||51||20170928 !09:30||30||5||yes||3|| ||52||20170928 !10:45||30||20||no||3|| =  = =  = = 9 - Table with Ice Shelf Experiments = ||EXP||Date||T (s)||dH (cm)||Q (l/min)||dRho (kg/m³)|| ||1||09/10/17 16:57||60||0||50||0||