December 7, 2019 at 12:20 amGeckooSubscriber
I want to inject liquid water in a chamber. I used a diamater number distribution provided by the manufacturer to calculate the Rosin Rammler-mean diamater and spread. As my results do not match my expectations I want to double check the diameter distributions injected.
First, I plotted a Histogram using data from trajectory samle files of two surfaces. These histograms indicate a rectangular distribution with 18 of the 20 bins around the same number of particles and the smalles diameters slightly less.
Then I calculated the number distribution using the initial values of the injection obtained by //define/injections/lp/myInjection.
Here the number distribution is extreme to the small diameters, with 1.3e+6 entries for the smallest diameter, 1.3e+3 for the second smallest and then exponentially decreasing to 3. The volume distribution has a gaussian shape but should be skewed towards the larger diameters.
As I disabled breakup and all particles pass the surface of the histogram both plots shall indicate generally the same shape, but they do not. What is the right way to determine the diameter distribution of an injector?
My properties: Inert particle type, solid cone injection, rosin-rammler distribution, Min Diam 1.07e-7, Max Diam 6.75e-5, Mean Diam. 4.36e-5, spread 3.561, Number of streams 20, number of diameters 20.
Thank you very much and best regards
December 7, 2019 at 6:58 amDrAmineAnsys EmployeeYou can just open injection panel then list the injection. Fluent writes the the output into console which you copy for further inspection. I will at first di that before looking into any other things.
December 7, 2019 at 8:19 pmGeckooSubscriber
Thank you Amine. This is the list obtained by //define/injections/lp/myInjection resulting in a Gaussian volume distribution.
Do you have an idea why the histogram of the trajectory sample files is so different?
All the best
December 9, 2019 at 6:20 amDrAmineAnsys EmployeeAre u sampling at inlet?
December 12, 2019 at 2:55 pmGeckooSubscriber
No at outlet and two other planes. But I think I have found my mistake. It is probably due to the format the reports are saved and thus cutting off values above 225,000.
December 12, 2019 at 4:19 pmDrAmineAnsys EmployeeOk.
December 21, 2019 at 7:43 pmGeckooSubscriber
Okay actually it just led to another problem. The histogram obtained by Results -> Plots -> Histogram look very different to the histogram obtained by the sampling files Results -> Reports -> Discrete Phase -> Histogram.
The extreme peak at 1.07e-7m, the minimum diamater, in the Sampling Histogram can also be seen in the injection list file. I'd be curious to know why there is such a peak but this is a different topic. In this case, breakup is enabled.
Does anyone know why they look so different? How does Fluent calculate the histograms?
Thank you very much and best regards
- 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
- Difference between K-epsilon and K-omega Turbulence Model
- The solver failed with a non-zero exit code of : 2
- Time Step Size and Courant Number
- Mesh Interfaces in ANSYS FLUENT
- error: Received signal SIGSEGV
© 2023 Copyright ANSYS, Inc. All rights reserved.