.jpg)
Gerd is recovering after a severe allergic reaction to a bee sting. Our thoughts are with Professor Masselink at what must be a painful and embarassing time for him
Monday 30 June 2008
BARDEX LOGBOOK 26/06/08 - 27/06/08
Thursday 26/06/08
Series A1: high lagoon (3.8 m), mean sea level (2.5 m). Pump on lagoon side again manually controlled by GM. An equilibrium groundwater profile was achieved and maintained for one hour. Over this hour both the lagoon and ocean water level was kept within 1 cm from the required level. Water levels were also manually recorded (see Table for measurements taken at 11:30; more in notebook). On the basis of these data a hydraulic conductivity of 0.11 m/s was computed. For information, during the period with stable water levels, the lagoon-in pump was working at 40% and the ocean out pump at 50%. The water level profile through the barrier is slightly convex.
After the groundwater test it was attempted to flatten the beach by hand. After 10-15 minutes shovelling, it was decided not to carry on. Because the beach was very disturbed, one hour of waves were run (Hs = 1 m; Tp = 4.5 s). The beach did not recover completely, but it looked good enough. This run was also logged by Deltares (SeriesA11).
Other activities:
· Rig 2 (main rig) was moved 2 m down the beach and Rig 1 was placed in its stead. The buried pressure sensors were also moved, but the cable was too short – needs sorting tomorrow.
· Sediment calibration photos were prepared and taken.
· Andre began work on preparing tracer for overwash experiments (orange, blue, and green)
· High impact PT prepared and tested at home.
· Found out that the origin for the Deltares profiles is 117.3 m.
Friday 27/06/08
Arrived at flume and sea level 0.5 m too high so after Deltares instruments had been zeroed the water was pumped back out. The cable for the subsurface pressure transducers was lengthened and an extra cross piece added to the scaffold frame in order for these PTs to log into the main logger at the main rig (which is now the seawards most rig – see yesterday’s entry). Series BB1: repeat of Series B1, but with smaller waves: Hs = 0.8 m, Tp = 4.5 s, ocean level = 2.5 m, lagoon level = 2.5 m. UoP and UNSW sensors were started at c. 10:30am, and the video approx 10:38. The waves were started approx 10:48. Waves for 1.5 hours and sequential surveys (5mins, 5mins, 5mins, 5mins, 10mins, 10mins, 15mins, 15mins, 20mins). The random waves run was followed by 5 mins of monochromatic wave conditions. Instruments were adjusted after every wave run.
· An interesting observation was that 5 mins of monochromatic waves caused significant erosion of the mid and upper beachface.
· Did calibration catalogues for two different digital grain size techniques, on both wet and dry images. Found out that both are suitable, and a hybrid of the two will be used from now on. The dry and wet sediments have a very different optical signature so the images will be inspected by eye before analysis, and the correct calibration catalogue used accordingly
· A normal run will now take this template. An hour or so is required in the morning for the Deltares staff to sync clocks, start the run, programme the wave steering signal, check water levels, and pump if necessary. Then 1 hours of waves are required to equilibrate the profile before the test run is carried out with the design wave. After 1.5 hours of the test condition, separated by profiles at 5, 10, 15, 20, 30, 40, 55, 70, and 90 mins. Afterwards, 5 mins of monochromatic waves should be sent down the flume, followed by a final survey. This will enable ensemble averages of the swash/hydrodynamic parameters to be calculated.
· Profile data %BB1EN1PRF.asc is suspect.
· Lower EMCM pair (+3 and 6 cm) looks broken.
Series A1: high lagoon (3.8 m), mean sea level (2.5 m). Pump on lagoon side again manually controlled by GM. An equilibrium groundwater profile was achieved and maintained for one hour. Over this hour both the lagoon and ocean water level was kept within 1 cm from the required level. Water levels were also manually recorded (see Table for measurements taken at 11:30; more in notebook). On the basis of these data a hydraulic conductivity of 0.11 m/s was computed. For information, during the period with stable water levels, the lagoon-in pump was working at 40% and the ocean out pump at 50%. The water level profile through the barrier is slightly convex.
After the groundwater test it was attempted to flatten the beach by hand. After 10-15 minutes shovelling, it was decided not to carry on. Because the beach was very disturbed, one hour of waves were run (Hs = 1 m; Tp = 4.5 s). The beach did not recover completely, but it looked good enough. This run was also logged by Deltares (SeriesA11).
Other activities:
· Rig 2 (main rig) was moved 2 m down the beach and Rig 1 was placed in its stead. The buried pressure sensors were also moved, but the cable was too short – needs sorting tomorrow.
· Sediment calibration photos were prepared and taken.
· Andre began work on preparing tracer for overwash experiments (orange, blue, and green)
· High impact PT prepared and tested at home.
· Found out that the origin for the Deltares profiles is 117.3 m.
Friday 27/06/08
Arrived at flume and sea level 0.5 m too high so after Deltares instruments had been zeroed the water was pumped back out. The cable for the subsurface pressure transducers was lengthened and an extra cross piece added to the scaffold frame in order for these PTs to log into the main logger at the main rig (which is now the seawards most rig – see yesterday’s entry). Series BB1: repeat of Series B1, but with smaller waves: Hs = 0.8 m, Tp = 4.5 s, ocean level = 2.5 m, lagoon level = 2.5 m. UoP and UNSW sensors were started at c. 10:30am, and the video approx 10:38. The waves were started approx 10:48. Waves for 1.5 hours and sequential surveys (5mins, 5mins, 5mins, 5mins, 10mins, 10mins, 15mins, 15mins, 20mins). The random waves run was followed by 5 mins of monochromatic wave conditions. Instruments were adjusted after every wave run.
· An interesting observation was that 5 mins of monochromatic waves caused significant erosion of the mid and upper beachface.
· Did calibration catalogues for two different digital grain size techniques, on both wet and dry images. Found out that both are suitable, and a hybrid of the two will be used from now on. The dry and wet sediments have a very different optical signature so the images will be inspected by eye before analysis, and the correct calibration catalogue used accordingly
· A normal run will now take this template. An hour or so is required in the morning for the Deltares staff to sync clocks, start the run, programme the wave steering signal, check water levels, and pump if necessary. Then 1 hours of waves are required to equilibrate the profile before the test run is carried out with the design wave. After 1.5 hours of the test condition, separated by profiles at 5, 10, 15, 20, 30, 40, 55, 70, and 90 mins. Afterwards, 5 mins of monochromatic waves should be sent down the flume, followed by a final survey. This will enable ensemble averages of the swash/hydrodynamic parameters to be calculated.
· Profile data %BB1EN1PRF.asc is suspect.
· Lower EMCM pair (+3 and 6 cm) looks broken.
Saturday 28 June 2008
Thursday 26 June 2008
BARDEX LOGBOOK 20/06/08 - 25/06/08
Friday 20/06/08
Arrived at the flume around 09:30 hrs. Received a safety briefing and were shown around. Unloaded the van, placed all scaffolding in the flume and organised the logging cabin.
Saturday 21/06/08
Installed all scaffolding and mounted all bed-level sensors, and also some bits of the swash rigs.
Sunday 22/06/08
Finished installing instruments and connecting them to computers in logging cabin. Also conducted the first survey in the flume (elevations of bed-level sensors and two benchmarks for resectioning) and constructed the offshore rig.
Monday 23/06/08
Tidied up around the flume and set swash rig instruments at correct elevations. Installed video camera and marked location on flume wall. Ian and Peter wrote instructions for Daniel to log instruments. Jon played around with offshore instrumentation. Flume was filled to 2.5 m, which took quite a long time (most of the day).
Tuesday 24/06/08
Placed four video GCPs on the flume wall and surveyed them in. Also surveyed in three video GCPS in the flume (sun shields of bed-level sensors 10, 20 and 30) and additional video GCP on the walkway op of drain. Deltares start their surveys by place wheel on base plate with known elevation (4.5 m). This base plate was also surveyed in and a linked file (bardex_linked_file.csv) was created with a large number of benchmarks inside and outside the flume with the datum the same as the one used by Deltares.
The groundwater run with a low lagoon level was carried out (Series A2). On problem that became apparent was that lowering the lagoon level too fast, causes a very steep hydraulic gradient at the back of the barrier, resulting in water to pour out, inducing sediment transport and channelling. The low ground water run was carried out with ocean level at 2.5 m and lagoon level at 0.8 m; a lower lagoon level is considered too risky. The run lasted four hours, after which the hydraulic gradient through the barrier was still slightly convex and not really approaching linear. However, the pump rate out of the lagoon, i.e., flow through the barrier, appeared reasonably stable. Several problems were identified in the data, the most serious one was the relatively large water level fluctuations in the ocean, due to the pumping routine not being sufficiently fine-tuned.
Wednesday 25/06/08
Today the run with the default wave conditions is planned (Series B1), with Hs = 1 m and Tp = 4.5 s. In the morning UoP set-up the logging, surveyed the tops of bed level sensors and took sediment photos (bed level sensors 8 – 44, two photos each). Still need to do calibration – will do a dry and a wet. Deltares were trying to sort out some pump and wave issues.
Waves were tested first in a series consisting of 20 mins Hs=0.5m, 5 mins of 0.80m and 5 mins of 1m waves. Then a series of runs of varying lengths at Hs=1m were carried out, reprofiling after each run.
Video was logged throughout. Sediment photos of the ‘wet bed’ were taken at the end.
Format of profile files:
· %B1GFN1.SEQ = a lot of logging and instrument information
· %B1GFN1.OUT = some logging and file name information
· %B1GFN1.DAT = binary data file
· %B1GFN1A1V1.OUT = a mixture of information (e.g., statistics, eps. Test)
· %B1GFN1PRF.ASC = data file in ascii; dodgy data at the end due to lifting out of the water of the wheel
· %B1GFN1PRF.DAT = binary data file
· %B1GFN1PRF.SEQ = some logging information
· %B1GFN1PRF.EPS = eps of profile
· %B1GFN1A1V1PRF.EPS = eps of profile change relative to original profile
Several problems occurred during Series B1:
· It was very difficult to keep the water level in the ocean constant at 2.5 m using the automatic pump system, whilst at the same time suppressing reflection at the paddle, because both respond to changes in the water level. Also with turning the reflection off it was difficult to keep the ocean level steady. Controlling the pumps manually was better, but the operator has to stay on the ball. The amount of water pumped out of the lagoon, should be the same as the amount of water to be pumped in the ocean, and by setting the pump percentage for the ocean the same as the one for the lagoon helps greatly in maintaining a steady water level.
· Stopping and starting the waves causes the wave set-up in the beach groundwater table to drop and fall. This is not ideal when one is interested in the beach groundwater table through the barrier. However, the groundwater table at the front of the barrier, especially in the swash zone, responds very quickly to turning waves on and off, and for the morphological response it should not make much of a difference whether waves are turned on and off or not.
· The main rig only occasionally received deep swashes and should really be moved 2 m down the beach. Rig 1 should be moved up by 2 m.
· Inspection of the Deltares data showed that the EMCM only recorded velocities of up to 1 m/s. This should be changed to deal with the stronger velocities.
· Tone hour of waves (1000 waves) was not sufficient to achieve equilibrium. We need to run at least 2000 waves.
Arrived at the flume around 09:30 hrs. Received a safety briefing and were shown around. Unloaded the van, placed all scaffolding in the flume and organised the logging cabin.
Saturday 21/06/08
Installed all scaffolding and mounted all bed-level sensors, and also some bits of the swash rigs.
Sunday 22/06/08
Finished installing instruments and connecting them to computers in logging cabin. Also conducted the first survey in the flume (elevations of bed-level sensors and two benchmarks for resectioning) and constructed the offshore rig.
Monday 23/06/08
Tidied up around the flume and set swash rig instruments at correct elevations. Installed video camera and marked location on flume wall. Ian and Peter wrote instructions for Daniel to log instruments. Jon played around with offshore instrumentation. Flume was filled to 2.5 m, which took quite a long time (most of the day).
Tuesday 24/06/08
Placed four video GCPs on the flume wall and surveyed them in. Also surveyed in three video GCPS in the flume (sun shields of bed-level sensors 10, 20 and 30) and additional video GCP on the walkway op of drain. Deltares start their surveys by place wheel on base plate with known elevation (4.5 m). This base plate was also surveyed in and a linked file (bardex_linked_file.csv) was created with a large number of benchmarks inside and outside the flume with the datum the same as the one used by Deltares.
The groundwater run with a low lagoon level was carried out (Series A2). On problem that became apparent was that lowering the lagoon level too fast, causes a very steep hydraulic gradient at the back of the barrier, resulting in water to pour out, inducing sediment transport and channelling. The low ground water run was carried out with ocean level at 2.5 m and lagoon level at 0.8 m; a lower lagoon level is considered too risky. The run lasted four hours, after which the hydraulic gradient through the barrier was still slightly convex and not really approaching linear. However, the pump rate out of the lagoon, i.e., flow through the barrier, appeared reasonably stable. Several problems were identified in the data, the most serious one was the relatively large water level fluctuations in the ocean, due to the pumping routine not being sufficiently fine-tuned.
Wednesday 25/06/08
Today the run with the default wave conditions is planned (Series B1), with Hs = 1 m and Tp = 4.5 s. In the morning UoP set-up the logging, surveyed the tops of bed level sensors and took sediment photos (bed level sensors 8 – 44, two photos each). Still need to do calibration – will do a dry and a wet. Deltares were trying to sort out some pump and wave issues.
Waves were tested first in a series consisting of 20 mins Hs=0.5m, 5 mins of 0.80m and 5 mins of 1m waves. Then a series of runs of varying lengths at Hs=1m were carried out, reprofiling after each run.
Video was logged throughout. Sediment photos of the ‘wet bed’ were taken at the end.
Format of profile files:
· %B1GFN1.SEQ = a lot of logging and instrument information
· %B1GFN1.OUT = some logging and file name information
· %B1GFN1.DAT = binary data file
· %B1GFN1A1V1.OUT = a mixture of information (e.g., statistics, eps. Test)
· %B1GFN1PRF.ASC = data file in ascii; dodgy data at the end due to lifting out of the water of the wheel
· %B1GFN1PRF.DAT = binary data file
· %B1GFN1PRF.SEQ = some logging information
· %B1GFN1PRF.EPS = eps of profile
· %B1GFN1A1V1PRF.EPS = eps of profile change relative to original profile
Several problems occurred during Series B1:
· It was very difficult to keep the water level in the ocean constant at 2.5 m using the automatic pump system, whilst at the same time suppressing reflection at the paddle, because both respond to changes in the water level. Also with turning the reflection off it was difficult to keep the ocean level steady. Controlling the pumps manually was better, but the operator has to stay on the ball. The amount of water pumped out of the lagoon, should be the same as the amount of water to be pumped in the ocean, and by setting the pump percentage for the ocean the same as the one for the lagoon helps greatly in maintaining a steady water level.
· Stopping and starting the waves causes the wave set-up in the beach groundwater table to drop and fall. This is not ideal when one is interested in the beach groundwater table through the barrier. However, the groundwater table at the front of the barrier, especially in the swash zone, responds very quickly to turning waves on and off, and for the morphological response it should not make much of a difference whether waves are turned on and off or not.
· The main rig only occasionally received deep swashes and should really be moved 2 m down the beach. Rig 1 should be moved up by 2 m.
· Inspection of the Deltares data showed that the EMCM only recorded velocities of up to 1 m/s. This should be changed to deal with the stronger velocities.
· Tone hour of waves (1000 waves) was not sufficient to achieve equilibrium. We need to run at least 2000 waves.
the wiener melange
This is the preferred coffee of the Bardex team - the wiener melange! Its a sweet mix of water, sugar, coffee, and chocolate. I think I've had too many this morning already while we wait for the pumping men!!!The Lady of Vollenhove
This lady has been drawn on the wall of the Deltaflume for good luck. She is currently 1m under the water and faces the paddle on the west side. She says "good luck Bardex". We say "thanks lady of Vollenhove"
Vla Flip - the perfect Dutch dessert
place a banana in the centre of a bowl and empty vanilla custard (vanille vla) one one side of it, and yoghurt on the other. Top with strawberry syrup and plenty of slagroom royale (see photo). Make sure the slagroom royale has plenty of stevig! Topping with 'halfwit' sugar is optional
thats the way to move gravel!
gerd and martin get a chance to break out of their namby-pamby academic existence and muscle in with the real men!
Meet the team (well, as of 23rd June -it changes all the time!)
from left to right: Ian Turner (UNSW), Dan Buscombe (UoP), Peter Ganderton (UoP), Martin Austin (UoP), Jon Williams (UoP), and Hoff Masselink (UoP)
Wednesday 25 June 2008
first tests
The first tests with waves are currently underway. We are testing the paddle with a series of 50cm waves, then 80cm, then 1m. We are then sending 2000 waves of JONSWAP spectrum Hs=1, Tm=3.75 (Tp=4.5) with eta=2.5m (SWL condition). The waves will be 'turned off' after set numbers of waves for barrier re-profiling and instrument position sets
Yesterday the tests were water levels only. The Delft technicians worked on their pumping routine in order to keep the water levels steady simultaneously on both the lagoon and ocean side. After looking at the data last night there were a few issues with their instrument conventions and set up which we have spent the morning resolving with them. So far, we are all happy and things are going well.
Ian T leaves in about 10 minutes, so Ian - keep watcdhing this space for updates!!
Yesterday the tests were water levels only. The Delft technicians worked on their pumping routine in order to keep the water levels steady simultaneously on both the lagoon and ocean side. After looking at the data last night there were a few issues with their instrument conventions and set up which we have spent the morning resolving with them. So far, we are all happy and things are going well.
Ian T leaves in about 10 minutes, so Ian - keep watcdhing this space for updates!!
Desert Island Discs
Ian
1. Crash - Dave Matthew's Band
2. Telemann - ViolaConcerto (2nd & 3rd movements)
3. Police - walking on the moon
4. Eurthymics - talking to an angel
5. Lloyd webber and Rice - close every door
1. Crash - Dave Matthew's Band
2. Telemann - ViolaConcerto (2nd & 3rd movements)
3. Police - walking on the moon
4. Eurthymics - talking to an angel
5. Lloyd webber and Rice - close every door
Tuesday 24 June 2008
Subscribe to:
Posts (Atom)
