Probe Definitions
Probe particles are created in order to extract accurate post-processing information from particular location, whether you want the information to come from a FLUID or a WALL or a MOVINGWALL phase.
probes
{
probe
{
probe_type volumeprobe
probe_name volumeprobeExample
probe_cntr "0.0 0.0 0.0”
probe_rad 0.25
probe_radodx 5
probe_phase 3
probe_shiftingaware true
}
probe
{
probe_type surfaceprobe
probe_name surfaceprobeExample
probe_cntr "0.0 0.0 0.0"
probe_rad 0.5
probe_radodx 9.5
probe_thck 0.05
probe_thckodx 3
probe_nrmvec "10.0 0.0 0.0"
probe_phase 3
probe_shiftingaware true
}
probe
{
probe_type solidprobe
probe_name solidprobeExample
probe_cntr "1.0 20.0 3.0"
probe_rad 1.0
probe_radodx 15.5
probe_phase 2
probe_movewith true
}
probe
{
probe_type flowrateprobe
probe_name flowrateprobeExample
probe_cntr "1.0 -1.0 -100.0"
probe_thck 0.2
probe_thckodx 2.5
probe_nrmvec "0.0 1.0 0.0"
probe_tanvec "5.0 0.0 0.0"
probe_points_file filename
probe_phase 3
probe_shiftingaware true
}
}
- probe_type
- Type of the probe used.
- volumeprobe assesses fluid properties
- surfaceprobe assesses fluid properties (mass flow).
- solidprobe assesses solid body properties.
- flowrateprobe is essentially a MASSFLOW equivalent.
- probe_name
- Probe name.
- probe_cntr
- Probe particle location.
- probe_rad
- Radius of the probe particle (influences the sample size).
- probe_radodx
- Radius of the probe as a function of dx, for example, when specified 3.0, implies 3.0*dx.
- probe_phase
- In case of volumeprobe, surfaceprobe and flowrateprobe this command specifies which phase motion the probe should follow.
- probe_movewith
- This command is applicable only to the solidprobe.
- probe_thck
- flowrateprobe and surfaceprobe are effectively 2.5D-like entities, where their definition is 2D, but in order to function properly, they need to consider a certain space before and after them, thus the thickness parameter.
- probe_thckodx
- Same as the previous command, except that it specifies the probe thickness as a relative function of the kernel size, for example, when specified 3.0, implies 3.0*dx.
- probe_nrmvec
- Vector specifying the surface normal of the probe.
- probe_tanvec
- This command specifies a vector which is co-planar with probe surface and at the same time defines the probe grid direction.
- probe_points_file
- Only applicable to flowrateprobe type.
- probe_shiftingaware
- This command enables the probes to consider the real convective velocity when using transport velocity or APD schemes.
Probes can provide a broad set of information about the area which they are monitoring. This data can be torque or forcing data (solid probes only), mass or volume flow rates, pressure values, density, viscosity or velocity. It is true that various applications require different measurements not just in terms of the monitored variable, but also in terms of time sampling or distinguishing the flow direction. In order to tackle all of these options, the PROBE output file can contain numerous columns.
- i - instantaneous information
- pta - periodic time average (averaged over the time between two outputs)
- TIME - time
- CNTR* - probe center
- CVEL* - probe center velocity
- NRMVEC* - normal vector of the probe
- NPART - average number of particles per 1dx thickness of probe
- oap - summation over all fluid phases
- abs* - absolute (does not consider probe velocity)
- rel* - relative (relative to probe velocity)
- *Vol* - Volume flow rate
- *Mss* - Mass flow rate
- *Co* - Component of flow in the probe normal direction
- *Flow - flow rate
Here are a few examples of column headers:
- pta_absVolFlow_1[m^3/s]
- Periodic time averaged absolute volumetric flow of phase 2.
- pta_relMssCoFlow_2[kg/s]
- Periodic time averaged relative mass flow in the direction of the probe normal for phase 2.
- pta_relVolFlow_oap[m^3/s]
- Periodic time averaged relative volumetric flow overall all phases (volumetric flow of all fluid phases).
- i_CNTR-Y[m]
- Instantaneous location of the probe center in Y direction.
- pta_absMssCoFlow_7[kg/s]
- Periodic time averaged absolute mass flow in the direction of the probe normal for phase 7.
To clarify, the term “periodic time average” implies a value that is time averaged over the period between two required outputs (dt_phaseinfo). The ns_phaseinfo command defines the number of samples that will be taken over the period of dt_phaseinfo and then averaged to provide the periodic time average value in the output.