Last month, I successfully used a line probe to sample the particle volume fraction. However, in yesterday’s simulation, the probe returned no simulation data, as shown in the figure, where exp:Cv represents the experimental data. Is the particle volume fraction stored in the cells, and can it be sampled using a line probe? Any help would be appreciated.
The simulation for coarse spherical particles lifting has already been completed, and Solution History data are available in STAR CCM+.
To obtain radial particle profiles, I created a Threshold derived part for the Lagrangian (DEM) phase within a thin axial region near the target cross-section.
The flow is fully developed from 3 s to 5 s. How can I obtain the time-averaged radial profiles of particle axial velocity and particle volume fraction over 3–5 s?
Can this be done directly from Solution History in STAR-CCM+, or is a Java macro required to loop over the recorded states?
I am simulating large-particle lifting in a vertical pipe with a Lagrangian particle model.
At one cross-section, I created 20 radial line probes in different circumferential directions. Each line has 20 points. I want to average values at the same radial position and plot radial profiles, e.g. particle volume fraction or particle velocity vs.r/R.263c9abf-c8dc-4822-8433-475adadc0d67
This works for fluid velocity, but I cannot extract particle velocity correctly. Also, the auto-generated Volume Fraction of Particles field function gives an unreasonable radial profile.
Can line probes sample Lagrangian particle data directly? What is the proper way to obtain radial profiles of particle velocity and particle volume fraction for Lagrangian particles in STAR-CCM+?
I am running a solid–liquid CFD-DEM simulation in STAR-CCM+ for lifting large particles in a vertical pipe. The segregated flow solver caused pressure divergence, while the coupled flow solver keeps the pressure stable. However, the residuals remain high and oscillatory. The outlet mass flow rate and pressure drop show an initial transient and then fluctuate around stable mean values. For this transient two-way coupled case, based on these results, can this simulation be considered successful or acceptable?
I am running a solid–liquid CFD-DEM simulation in STAR-CCM+ for lifting large particles in a vertical pipe. The segregated flow solver caused pressure divergence, while the coupled flow solver keeps the pressure stable. However, the residuals remain high and oscillatory. The outlet mass flow rate and pressure drop show an initial transient and then fluctuate around stable mean values. For this transient two-way coupled case, based on these results, can this simulation be considered successful or acceptable?
I am trying to reproduce a CFD-DEM simulation of coarse particles hydraulically conveyed upward in a vertical pipe using Simcenter STAR-CCM+. The pipe diameter is 30.6 mm, length is 2.4 m, particle diameter is 2.32 mm(greater than cell size), particle density is 2450 kg/m3, and the target solid volume fraction is about 2.2%. The pure-water case gives a reasonable pressure drop of about 28 kPa. With particles injected but two-way coupling disabled, the pressure drop also remains reasonable. However, as soon as I enable two-way coupling, the solution becomes unstable: the pressure-drop monitor shows large oscillations/spikes and the maximum particle velocity can quickly rise to around 20 m/s. I have tried using a part injector located 0.3 m downstream of the inlet, matching the particle injection velocity to the local fluid velocity, specifying particle mass flow rate, reducing the two-way coupling under-relaxation factor, reducing the time step, increasing inner iterations, enabling Volume Source Smoothing with Cell Cluster, and setting the Cell Cluster length to 7 mm, but the instability remains.What settings are recommended in STAR-CCM+ for stable unresolved CFD-DEM two-way coupling when the particle diameter is larger than some local CFD cells?
I am trying to reproduce a CFD-DEM simulation of coarse particles hydraulically conveyed upward in a vertical pipe using Simcenter STAR-CCM+. The pipe diameter is 30.6 mm, length is 2.4 m, particle diameter is 2.32 mm(greater than cell size), particle density is 2450 kg/m3, and the target solid volume fraction is about 2.2%. The pure-water case gives a reasonable pressure drop of about 28 kPa. With particles injected but two-way coupling disabled, the pressure drop also remains reasonable. However, as soon as I enable two-way coupling, the solution becomes unstable: the pressure-drop monitor shows large oscillations/spikes and the maximum particle velocity can quickly rise to around 20 m/s. I have tried using a part injector located 0.3 m downstream of the inlet, matching the particle injection velocity to the local fluid velocity, specifying particle mass flow rate, reducing the two-way coupling under-relaxation factor, reducing the time step, increasing inner iterations, enabling Volume Source Smoothing with Cell Cluster, and setting the Cell Cluster length to 7 mm, but the instability remains.What settings are recommended in STAR-CCM+ for stable unresolved CFD-DEM two-way coupling when the particle diameter is larger than some local CFD cells?
In my STAR-CCM+ CFD-DEM simulation, the particle size is greater than the cell size. Thus, I used Volume Source Smoothing (Cell Cluster size = 2 * particle size).
I need to plot the radial profiles (along the radius) of two parameters:
Since the smoothing method filters the particle volume onto the fluid mesh, what is the best way to extract these radial distributions? Can anyone help me? Thanks.
Hi there.
In my CFD-DEM simulation, the particle size is greater than the cell size. Thus, I used the volume source smoothing method and set the cell cluster size to twice the particle size for two-way coupling. However, the averaged solid volume fraction and axial particle velocity in the radial direction are totally different from those measured in previous experiments. By the way, the particle velocity is mapped through the parcel data mapper.
Can anyone help me? Thanks.
Hi there.
In my CFD-DEM simulation, the particle size is greater than the cell size. Thus, I used the volume source smoothing method and set the cell cluster size to twice the particle size for two-way coupling. However, the averaged solid volume fraction and axial particle velocity in the radial direction are totally different from those measured in previous experiments. By the way, the particle velocity is mapped through the parcel data mapper.
Can anyone help me? Thanks.