1. SPDA-1-3-OBS Software Upgrade
Summary of Progress in 2017 and Scopes
Kourosh Abdolmaleki
October 24, 2018

2. Contents Project Updates
Progress of Phases 4 and 5 (2017 and 2018) Scopes
Project Forecast
Summary of CFD Findings
CFD Work breakdown and Approach
Results of Current and Waves
CFD Simulation Process and Automation
Using Pawsey Supercomputing
Additional CFD results

3. 2017 Scope Progress
There has been changes in the project team – The CFD engineer has resigned. It is expected that the simulations will finish by Jan2019.
The matrix of simulations include larger pipe diameters than planned with many combination of input parameters
These additional simulations were conducted to complement the DHI model tests for the conventional pipe diameters.
It is crucial to do these simulations because the CFD results confirmed that oscillating the pipe to resemble waves would not produce the same results as oscillating the flow.

4. 2018 Scope Progress OBS Software Upgrade 1
Milestone 5 Task #
Description
Remarks
OBS Software Upgrade 1
Develop Batch run mode for Level2
95% 2
Implementation of a Model checker for Level 3
25% 3
Saving and Plotting the Level 3 results for all Seeds
100%
CFD Scope 4
Conduct parametric study and create database of force coefficients - Piggy-Back Pipes
On-Hold: swap funds-see next slides 5
High Performance Computing Cost
Implementation of CFD into the OBS Software 6
Implementation of force Coefficients in the Level 2 of OBS
Pending on completion of the single pipe simulations – expected to be completed in 1Q 2019. 7
Update the UI to allow for additional input data 8
Software validation 9
Draft technical note
Reporting - Software 10
Updating the help file to include the new additions
50% 11
Issue software Beta version
30% 12
Issue final report and software 5% 13
Project Management
On going

5. 2018 Scope proposed changes
2018 Scope (Milestone 5)
Milestone 5 Task #
Description
Amount (USD)
OBS Software Upgrade 1
Develop Batch run mode for Level2
$28,000 2
Implementation of a Model checker for Level 3
$5,000 3
Saving and Plotting the Level 3 results for all Seeds
$4,000
CFD Scope 4
Investigation on the effect of the CFD results on the stability requirements using Level2
$27,400
Implementation of CFD into the OBS Software 6
Implementation of force Coefficients in the Level 2 of OBS via trying machine learning technics
$45,000 7
Update the UI to allow for additional input data
$15,000 8
Software validation
$17,000 9
Draft technical note
$11,000
Reporting - Software 10
Updating the help file to include the new additions
$10,000 11
Issue software Beta version
$8,000 12
Issue final report and software
$7,000 13
Project Management
TOTAL
$177,400
To Replace the Piggy-back scope with a new task that the members have already requested.
The piggy-back scope is shifted to 2019 scope.
Machine learning technics would enable the software to run faster. Additional $22,700 has been requested.

6. Level2 Batch (Batch Input Data)
Define Ranges : The range can be multiple custom and regular ranges, simultaneously
Custom values format: val1,val2,….,val n;
Regular ranges: Lowest:Highest:Increment
list of parameters based on selection of optional parameters
List of all batches
Define optional parameters
List of customised parameters
Note: value of parameters that are not included in this list, would be default value

7. Level2 Batch (Generated Cases)
Generating batch cases by product of all values of all parameters

8. Level2 Batch (Batch Input Data Exp.2)

9. Level2 Batch (Generated Cases Exp.2)
Shows the combination parameters validity, (checking the minimum water-depth and wave-height combination)
List of errors and warnings

10. Computational Fluid Dynamics for Small Diameter Pipes Summary of Findings

11. Motivation Unrealistic pipe “Sg” requirement for small diameter pipes
Limited availability of data for small diameter data, i.e. large KCs.

12. Work breakdown and Approach
Simulations were grouped as per the following:
Description
Main Activities
Steady flows on seabed with roughness in the absence of pipe
each group required:
Literature review for find published data for validation
Identify range of parameters for simulation
Numerical setup
Mesh optimisation and convergence study
Studying 3D effects
Program scripts for pre-processing, extracting forces and post-processing the results
Program scripts for batching the simulations and launching the runs on supercomputer
Total data generated is estimated around 15 TB !!!
Oscillatory flows on seabed with roughness in the absence of pipe
Steady flow around pipe with smooth and rough surfaces with no bottom boundary
Steady and oscillatory flows around stationary pipe on seabed with roughness
Oscillating pipe in still water on seabed with roughness
Piggy-back configuration of pipes in steady flows

13. Range of Parameters for CFD Modeling
The range of parameters for CFD modelling
Pipe Dia. (m)
Pipe roughness (m)
Sea bed roughness (m)
Curr. Vel(m/s)
Wave Vel. (m/s)
Wave Period (s)
5× 10 −6 - 5× 10 −2
1.5× 10 −
0.1 – 2.0
4.0 – 18.0
The plot presents contours of: Reynolds no. (Blue lines) ( 𝑅𝑒 𝑐 ≤6× 10 5 ) KC no. (red lines) for the given range in the Table. 𝐾𝐶≤360

14. Summary of conclusions (Current only)
The hydrodynamic coefficients are generally function of Reynolds number for a given seabed and pipe roughness values.
Increasing the pipe roughness will result in an increase in drag coefficient.

15. Summary of conclusions (Current only)
The hydrodynamic coefficients are generally function of Reynolds number for a given seabed and pipe roughness values.
Increasing the pipe roughness will result in decrease in lift coefficient.

16. Summary of conclusions (Wave only)
Simulations were performed with moving pipe in a stationary flow and compared against the oscillatory flow over a stationary pipe. The results concluded that the flow field around the moving pipe in a stationary flow would differ from fixed pipe in oscillating flow and hence different hydrodynamic coefficients.
Drag Force
Lift Force

17. Summary of conclusions (Wave only)
Oscillating Flow
Oscillating Pipe
𝑡= 𝑛 𝑇 𝑤
𝑡= 𝑛 𝑇 𝑤
𝑡= 𝑛 𝑇 𝑤

18. Summary of conclusions (Wave only)
Oscillating Flow
Oscillating Pipe

19. Summary of conclusions (Wave only)
The Fourier coefficients are generally KC dependent for a given seabed and Pipe roughness values.
Variation of mean lift coefficient with KC for different pipe diameters and wave periods

20. Summary of conclusions (Wave only)
The Fourier coefficients are generally only KC dependent for a given seabed and Pipe roughness values
Variation of drag coefficient with KC for different pipe diameters and wave periods

21. Summary of conclusions (Wave only)
The Drag Fourier coefficients increase as Pipe roughness increases and decrease as Seabed roughness increases
Variation of drag coefficient with KC for different pipe and seabed roughnesses

22. Summary of conclusions (Wave only)
The Lift Fourier coefficients decrease as Pipe roughness increases and decrease as Seabed roughness increases
Variation of lift coefficient with KC for different pipe and seabed roughnesses

23. Comparison with DHI
Lift and Drag coefficients corresponding to maximum Forces

24. Extra slides

25. Proposed 2019 scope for off the ballot funding
Proposed Tasks for 2019 Scope (Milestone 6)
Milestone 6 Task #
Description
Amount (USD) 1
Model test of Piggy-back pipe arrangements
TBA* 2
Conduct parametric study and create database of force coefficients - Piggy-Back Pipes
$55,000 3
High Performance Computing Cost
$15,000 6
Implementation of force Coefficients in the Level 2 of OBS
$30,000 7
Update the UI to allow for additional input data 8
Software validation
$17,000 9
Draft final report
Issue final report and software
$5,000
TOTAL
$152,000
UWA O-Tube cost $2200 per day. Cost of data post-processing should be aded
In case of joint publications with UWA their rates can be slightly reduced.