Probes

Probe particles are created in order to extract accurate post-processing information from a particular location, such as a FLUID or a WALL or a MOVINGWALL phase.

Commands

Note: It is possible to define both static and moving probe particles.
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                        
    }
}

Definitions

Command Contents SI Unit Example
probe_type Type of the probe used
Options
  • 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
Note: When flowrateprobe is comprised of multiple particles, probe_cntr represents a sort of reference point in cases where the probe is supposed to move.
probe_rad Radius of the probe particle
Note: Influences the sample size.
Unit: [m]
probe_radodx Radius of the probe as a function of d x MathType@MTEF@5@5@+= feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamizaiaadI haaaa@37D9@
Tip: For example, when probe_radodx is set as 3.0, this implies 3.0 * d x MathType@MTEF@5@5@+= feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaaG4maiaac6 cacaaIWaGaaiOkaiaadsgacaWG4baaaa@3AB0@ .
Attention: If both probe_rad and probe_radodx are specified, the latter one takes precedence.

Default = kernel cut-off size (3.0 for quintic spline)

probe_phase In cases of:
  • volumeprobe, surfaceprobe and flowrateprobe this command specifies which phase motion the probe should follow.
    Tip: For example, if you specify phase 3, and that phase is a MOVINGWALL with assigned rotation, than the probes will follow the same motion.
  • solidprobe, this command specifies which solid phase is monitored.
probe_movewith Command solidprobe points to a particular phase for monitoring, where this command determines whether the probe is also moving with that phase or not.
Note: This command is applicable only to the solidprobe.
Options
  • true
  • false

Default = false

probe_thck This command specifies the absolute thickness of the probes. Commands 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 and require a thickness parameter. Unit: [m]
probe_thckodx Same as the above command, except that it specifies the probe thickness as a relative function of the kernel size.
Tip: For example, when probe_radodx is set as 3.0, this implies 3.0 * d x MathType@MTEF@5@5@+= feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaaG4maiaac6 cacaaIWaGaaiOkaiaadsgacaWG4baaaa@3AB0@ .

Default = 1.0*dx MathType@MTEF@5@5@+= feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaaGymaiaac6 cacaaIWaGaaiOkaiaadsgacaWG4baaaa@3AAE@

probe_nrmvec Vector specifying the surface normal of the probe. Flow passing in the same direction as this vector will be noted as a positive value flow.
probe_tanvec Specifies a vector which is co-planar with probe surface and at the same time defines the probe grid direction.
Note: This command is optional.
probe_points_file Makes it possible to have a separate file with cloud point data (simple X, Y, Z coordinates; delimiter is space) and use it as a definition for the flowrateprobe probe particles.
Note: Only applicable to flowrateprobe type.
probe_shiftingaware Enables the probes to consider the real convective velocity when using transport velocity or APD schemes.
Tip: It is recommended that this option remains true.

Default = true

PROBE Output File

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. 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.

The following is a list of several keywords which help explain the meaning of the columns, followed by a few examples.
Note: The asterisk * symbol means that you can find other extensions before or after the keyword.
  • 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

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.
Note: 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.