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

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

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.

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

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.

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

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

Level2 Batch (Batch Input Data Exp.2)

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

Computational Fluid Dynamics for Small Diameter Pipes Summary of Findings

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

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

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) 0.1 - 0.4 5× 10 −6 - 5× 10 −2 1.5× 10 −4 - 0.01 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

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.

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.

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

Summary of conclusions (Wave only) Oscillating Flow Oscillating Pipe 𝑡= 𝑛+ 1 4 𝑇 𝑤 𝑡= 𝑛+ 1 2 𝑇 𝑤 𝑡= 𝑛+ 3 4 𝑇 𝑤

Summary of conclusions (Wave only) Oscillating Flow Oscillating Pipe

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

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

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

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

Comparison with DHI Lift and Drag coefficients corresponding to maximum Forces

Extra slides

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.