Measurements

Probes

Analysis > Measurements > Probes

Probes are nanoFluidX features used for extracting accurate post-processing information from a particular location, such as pressure or mass flow.

Create Probe in SimLab
  • Name: User defined probe name.
  • Probe Type: Specifies the type of the probe – Pressure and Mass flow.
  • Moving body motion to follow: Probes can follow a MOVINGWALL phase with predefined motion.
  • Particle shifting aware: Enables the probes to consider the real convective velocity when using transport velocity or APD schemes.
  • Other Options: A free text box where additional parameters can be specified.

Dye Region

Analysis > Measurements > Dye Region

Dye regions are used for fluid phase tracking and are in that sense analogous to the well-known experimental method of flow visualization.

It is possible to define an arbitrary number of dye regions in a simulation with the same or different color. As a fluid particle (irresectable of its phase definition/density) passes through a given dye region, it will get assigned a specified “color” (integer, scalar property which is then output in the particle data). Usage of dye regions eliminates the need to use multiple fluid phase definitions in order to track the fluid flow from a specific location and are therefore more computationally efficient.

Dye regions can only be spherical in shape. If a particle passes through multiple dye regions, it will adopt the color of the last dye region through which it passed.

Define Dye Region in SimLab

A sphere region can be defined using this panel.

  • Name: Dye region name.
  • Color ID: Color ID assigned to the dye region.
  • Start Time/ End Time: Specifies the start and finish times which define the window where the Outlet region is active.
  • Other Options: A free text box where additional parameters can be specified.

Extractor

Analysis > Measurements > Extractor

Extractors are intended to provide more flexible post-processing and interpolation options by enabling runtime interpolation, access to solid data, moving interpolation surfaces, custom output times and providing variables that are not immediately available through regular field output.

An extractor consists of a set of interpolation points that may follow a solid phase of interest and interpolate different simulation variables at set sampling intervals. Similar to probes and phase info, extractors have access to all simulation data of each phase, solid or fluid, at all times and thus can produce more accurate interpolations, instantaneous or periodically time averaged, compared to those relying on field output.

Create Extractor in SimLab
  • Name: Extractor name
  • Input – Extract Faces: The selected faces option is used to select the faces of input mesh bodies that should be used as an extractor. For the selected faces, an STL file will be exported.
  • Flow Outputs:
    • Density: This is the value of fluid density at the extractor point. When surrounded by fluid phases and away from any solid, an extractor point interpolates the density of the particles assuming constant particle volume.
    • Pressure: Pressure of the fluid interpolated from fluid and solid particles. The pressure on the solid particles is the value required to satisfy boundary conditions on the fluid.
    • Velocity: Velocity of the fluid interpolated from fluid particle velocity and solid particle boundary velocity.
  • Fluid Contact Time: Periodically averaged fluid contact time.
  • Heat Transfer Coefficient: Empirical - The empirical formula for an isothermal flat plate heating fluid is used to calculate an HTC value based on a locally interpolated velocity. The obtained HTC is then averaged over a number of snapshots.
  • Output time interval: The time interval between non-synchronized outputs, starting from the beginning of this run segment.
  • Advanced Options:
    • Follow moving body: The extractor can follow a MOVINGWALL phase with predefined motion.
    • Other Options: A free text box where additional parameters can be specified.