Pathline Defintion
Description
Enabling
General
Particle source
Start node selection
Results
Sources
Sphere sources
Plane sources
Description
The pathline definition panel is part of the pathlines
dialog box. It is used to define how pathlines will be generated.
Pathlines are generated by allowing particles to pass between nodes that have
been defined in the data source. The process is random, but the probability of a
particular path being followed depends on the properties of the nodes. The start
node for each pathline and the limits placed on the pathlines are controlled by the
parameters in this panel.
Each pathline starts from a node in the start region defined by one of the
sources. It then travels from node to node until it leaves the realisation
volume or until it exceeds the maximum number of time steps or the maximum time.
It is possible for a pathline to get stuck at a particular node, in which case
the pathline is also terminated. If there are no nodes in a start region then
no pathlines will be generated from that source. It is also possible for a
pathline to terminate as soon as it starts, in which case it may not be visible.
Enabling
Pathlines can be enabled and disabled using the Show pathlines
check box. If this check box is unticked then the rest of the panel becomes disabled
and pathlines are not displayed.
General
These are general parameters that affect the pathline generation process.
- Data source
- The source of the pathline data can be selected from this list.
The list is disabled if there is only one data source
The data source provides information about the nodes that the pathlines will follow.
- Max steps
- The maximum number of steps each pathline can take.
- Max time
- The maximum time each pathline can take.
- Seed
- The random number seed used for randomly generating the pathlines.
The same seed will always generate the same pathlines if all other parameters are constant.
Particle source
The Particle source sub-panel defines the particle source type.
Note that changing the source type will remove all currently defined sources.
- Sphere source
- The pathline start region is spherical.
When this option is chosen the Sphere sources
become visible.
- Sphere source
- The pathline start region is planar.
When this option is chosen the Plane sources
become visible.
Start node selection
The Start node selection sub-panel defines how the start node for each
pathline is selected.
- Nearest node
- The start node nearest to the centre of the start region is used.
- Random
- The start node is randomly selected from the nodes within the start region.
- Flux weighted random
- The start node is randomly selected from the nodes within the start region,
but the probability of selecting a node is weighted by the relative flux at that
node.
Results
The Results sub-panel specifies whether the results of pathline
generation are to be shown and how they should be represented.
- Show results
- If the Show results check box is ticked then the results from
pathline generation are displayed after the OK or Apply buttons are
clicked.
- Time unit
- The unit of time to use when displaying the results.
The image below shows the results for 7 pathlines generated from 2 planar
sources.
The results are shown for each pathline and then summarised for all pathlines.
The percentile rows show the minimum value of each result achieved by the given
percentage of pathlines.
Clicking the Close button closes the results dialog box.
Clicking the Save button saves the results to a file in HTML format or in
comma separated value (CSV) format, suitable for loading into a spreadsheet.
Sources
The Sphere sources and Plane sources sub-panels each contains a
table that defines the start regions for the pathlines. The type of table shown
depends on the particle source type selected.
Each row in the table represents the definition of a single source.
The following buttons are available for both types of source:
- Add
- The Add button adds a new source to the table.
By default, each new source has the same parameters as the last source in the
table. If there are no sources in the table the new source is defined to be
centred on the centre of the realisation and equal in size to the largest
dimension of the bounds of the realisation. Plane sources are vertical by default.
- Remove
- The Remove button removes the selected sources from the table.
Shift or ctrl clicking can be used to select more than one source.
- Clear
- The Clear button removes all sources from the table.
Sphere sources
The Sphere sources sub-panel defines the start region for pathlines
originating from spherical sources.
The following properties can be set for each sphere:
- Centre X
- The X coordinate of the centre of the sphere in metres.
- Centre Y
- The Y coordinate of the centre of the sphere in metres.
- Centre Z
- The Z coordinate of the centre of the sphere in metres.
- Radius
- The maximum distance a start node can be from the centre of the
sphere. This represents the radius of the sphere.
- No. particles
- The number of particles to generate from the sphere source.
Plane sources
The Plane sources sub-panel defines the start region for pathlines
originating from planar sources.
The following properties can be set for each plane:
- Centre X
- The X coordinate of the centre of the plane in metres.
- Centre Y
- The Y coordinate of the centre of the plane in metres.
- Centre Z
- The Z coordinate of the centre of the plane in metres.
- Strike length
- The length of the plane along the plane strike in metres.
- Dip length
- The length of the plane along the plane dip in metres.
- Dip
- The dip angle of the plane in degrees.
This is the angle of the plane below the horizontal.
- Strike
- The strike angle of the plane in degrees.
This is the angle of rotation of the plane around the Z axis. Zero degrees is along the positive Y axis.
- Orientation
- The orientation angle of the plane in degrees.
This is the angle of rotation of the plane around its own principal axis.
- Distance
- The maximum distance a start node can be from the plane. This
represents the half thickness of the plane.
- No. particles
- The number of particles to generate from the plane source.
Please email comments to:gw.support@sercoassurance.com
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