© 2014 ANSYS, Inc. September 19, 2014 1
ANSYS Aqwa 16.0 Preview 4
© 2014 ANSYS, Inc. September 19, 2014 2
• Workbench Integration – Aqwa-Librium – Aqwa-Fer
• Workbench Usability – Display Starting Position – Propagate Environmental Data to Linked Systems – Copy/Paste Tree Items
• Diffraction Analysis Enhancements – Solve for Lower Wave Frequencies – Maximum Number of Frequencies Raised – Calculation of Very High and Very Low Frequencies
• High Performance Computing (HPC) – Diffraction – Cable Dynamics
• Miscellaneous – Design Point Updating – Idle Timeout
Summary
© 2014 ANSYS, Inc. September 19, 2014 3
Workbench Integration - Aqwa-Librium
• It is now possible to carry out a static equilibrium analysis in Workbench
– At present this is achieved by setting the Computation Type of a Hydrodynamic Response Analysis to “Stability Analysis”
• The dynamic stability capability of Aqwa-Librium is not yet available through Workbench
© 2014 ANSYS, Inc. September 19, 2014 4
Workbench Integration - Aqwa-Fer
• It is now possible to carry out a Frequency Domain analysis in Workbench
– At present this is achieved by setting the Computation Type of a Hydrodynamic Response Analysis to “Frequency Statistical Analysis”
• The results available are graphs of RAOs, Response Spectra etc. and tabular output of significant values
© 2014 ANSYS, Inc. September 19, 2014 5
Workbench Integration - End-to-End Hydrodynamic Analyses
• Workbench project page showing linked Geometry, Diffraction, Stability, Frequency and Time Response Analyses
– Stability, Time & Frequency Response analyses now conducted using the “Hydrodynamic Response” Analysis System
© 2014 ANSYS, Inc. September 19, 2014 6
Workbench Usability - Display Starting Position
• Workbench now shows the system at its equilibrium starting position before the analysis is run
– Previously it was necessary to perform the solution before displaying “Step 1”
Initial geometry
Starting position
© 2014 ANSYS, Inc. September 19, 2014 7
Workbench Usability - Propagate Environmental Data to Linked Systems
• It is common for Equilibrium, Frequency and Time Domain analyses to use the same environmental data, which can be time-consuming to set up
– It is now possible to propagate this down from the Equilibrium analysis, ensuring that consistent data is used for each linked analysis
© 2014 ANSYS, Inc. September 19, 2014 8
Workbench Usability - Copy/Paste Tree Items
• It is now possible to Copy/Paste and Duplicate tree items, saving time in setting up (e.g.) mooring systems which have several similar cables
© 2014 ANSYS, Inc. September 19, 2014 9
Diffraction Analysis Enhancements - Solve for Lower Wave Frequencies
• The Green’s Function database has been extended allowing Aqwa-Line and Hydrodynamic Diffraction in Workbench to solve for lower wave frequencies
• The lower limit depends on the water depth and has been reduced by a factor of 50 from:
0∙05.max{1,√(g/d)} rad/s to
0∙001.max{1,√(g/d)} rad/s
• This will be a benefit in two main areas:
1. In shallow water where it is sometimes necessary to use frequencies below 0.05 rad/s
2. When forward speed causes a low encounter frequency
© 2014 ANSYS, Inc. September 19, 2014 10
Diffraction Analysis Enhancements - Maximum Number of Frequencies Raised
• The maximum number of wave frequencies in Aqwa-Line has been doubled from 50 to 100
– This has been a fairly frequent request from customers, and fits well with the increase in speed from parallelization and the reduction in the minimum frequency allowed
– Users can now solve more frequencies over a wider range in less time than in R15.0
Using 50 frequencies Using 100 frequencies
© 2014 ANSYS, Inc. September 19, 2014 11
Diffraction Analysis Enhancements - Calculation of Very High and Very Low Frequencies
• Aqwa-Line now automatically calculates the lowest possible wave frequency, in addition to the frequencies specified by the user
– This allows a more accurate calculation of the so-called “5th term” of the QTF coefficients
– The damping at this low frequency is also used to calculate the impulse response function for the convolution of radiation forces
• Aqwa-Line now automatically calculates a very high wave frequency, in addition to the frequencies specified by the user
– This is used as the “infinite frequency” added mass in the radiation force calculation
© 2014 ANSYS, Inc. September 19, 2014 12
High Performance Computing (HPC) - Diffraction
• Parallel processing has been implemented for the diffraction calculations in Aqwa
– Works with all ANSYS HPC & ANSYS HPC Parametric Pack options
• Significant speed-up in serial also achieved from further changes to the diffraction solver code
Version & No.
of Cores
R15
Serial
R16.0
Serial
R16.0
2 cores
R16.0
4 cores
R16.0
8 cores
Time (s) 101830 20522 13021 8369 6442
Factor N/A 5.0 7.8 12.2 15.8
Test model with 22276 panels (no. of cores and version varied)
© 2014 ANSYS, Inc. September 19, 2014 13
High Performance Computing (HPC) - Cable Dynamics
• Parallel processing has been implemented for the cable dynamics calculations in Aqwa
– Most effective as number of cables elements increases
Test model of a simple box with four cables (no. of cores & cable elements varied)
No. of cable
elements 50 150 250
No. of Cores Time (s) Factor Time (s) Factor Time (s) Factor
1 (Serial) 96.7 1 250.8 1 404.2 1
2 51.7 1.9 128.9 1.9 205.9 2.0
4 27.8 3.5 64.9 3.9 101.0 4.0
© 2014 ANSYS, Inc. September 19, 2014 14
Miscellaneous
• Design point updating
– A long-standing defect related to design point updating has been fixed, so users will find it much easier to make practical use of the design point capability in Workbench
• Idle timeout enabled