TAGGED: cfd, cfx, lagrangian, particle-tracking, particle-variables
May 27, 2022 at 4:41 amlydauSubscriberHi all,
I am working on droplet transmission from human exhalation in a room using Lagrangian Particle Tracking (LPT) with evaporation model. Both steady state and transient simulations ran well without error. However, I'm having issues extracting the particle variables (diameter, number rate, temperature, velocity, components' mass fraction, etc) at any point (spatially) within the room. From CFX documentation, particle variables in LPT can be track variables or field variables and that spatial values of particle information are captured with particle field variables. Unfortunately, I've been unable to get these variables for any points in the domain. I am wondering if anyone have worked on LPT in CFX and how the particle field variables are extracted.
Thanks in anticipation of your feedback.
May 29, 2022 at 6:47 pmrfblumenAnsys EmployeeFor Particle Transport Modeling in CFX, two types of variables are available: Particle Track Variables and Particle Field Variables. The particle variables that you mention (diameter, number rate, temperature, velocity, components' mass fraction, etc.) are associated with Particle Track Variables and by default are only available for quantitative post-processing if the particle tracks (and the associated track variables) are exported from Post and post-processed outside of CFD-Post. This can be done using Fortran or similar where for a given (x,y,z) location, each particle track is followed from start to end and the minimum distance (along with the particle track variables) to the desired point is determined. The particle track variable values for each particle track can then be tabulated and some averaging of the information can be done for tracks that are within some radius of the desired point.
Another approach, if the goal is post-processing Particle Track Variables within CFD-Post at a specific (x,y,z) location, is to work with Particle Vertex Variables (see 18.104.22.168. Particle Vertex Variables in the CFX Reference Guide). In CFX-Pre, variables such as Average Mean Particle Diameter, Averaged Particle Number Rate, etc. can be selected from the Extra Output Variables List in the Output Control section. In CFD-Post, these variables can be post-processed in the same way as fluid variables. A point can be created in the domain at some (x,y,z) and the probe function can be used in the Function Calculator to extract the desired particle variables.
- You must be logged in to reply to this topic.
Boost Ansys Fluent Simulations with AWS
Computational Fluid Dynamics (CFD) helps engineers design products in which the flow of fluid components is a significant challenge. These different use cases often require large complex models to solve on a traditional workstation. Click here to join this event to learn how to leverage Ansys Fluids on the cloud, thanks to Ansys Gateway powered by AWS.
Earth Rescue – An Ansys Online Series
The climate crisis is here. But so is the human ingenuity to fight it. Earth Rescue reveals what visionary companies are doing today to engineer radical new ideas in the fight against climate change. Click here to watch the first episode.
Subscribe to the Ansys Blog to get great new content about the power of simulation delivered right to your email on a weekly basis. With content from Ansys experts, partners and customers you will learn about product development advances, thought leadership and trends and tips to better use Ansys tools. Sign up here.
- Suppress Fluent to open with GUI while performing in journal file
- Floating point exception in Fluent
- What are the differences between CFX and Fluent?
- Heat transfer coefficient
- Getting graph and tabular data from result in workbench mechanical
- The solver failed with a non-zero exit code of : 2
- Difference between K-epsilon and K-omega Turbulence Model
- Time Step Size and Courant Number
- Mesh Interfaces in ANSYS FLUENT
- error in cfd post
© 2023 Copyright ANSYS, Inc. All rights reserved.