Measuring Flow

edited November 2017 in DualSPHysics_v4.0

I have been working on my graduation project in engineering using DualSPHysics and so far I have been able to change the boundary factor and other factors to fit my cases of study. Your paper "Integration of UAV Photogrammetry and SPH Modelling of Fluids to Study Runoff on Real Terrains" has been particularly useful.

I have come to the point where I need to measure flow in order to compare my results with other methods. I can see some options
-Using the average speed of the cross section I am interested in and just use Q=VA because I am using regular geometry (rectangular), but this will prove to be more difficult when I intend to apply it to less regular geometries. (river)

-The following is mentioned in the paper "The numerical inflow needs to be 0.5 m3/s, each m3 contains 17,802 particles so 8,901 particles are being inserted per second." However, this requires me to be able to create new particles with time and as far as I have read I can not create new particles as of this version. Therefore, this method does not seem likely

-Last thing I could come up with is using the measuring tool to get -mass, but I am getting the volume of 1 particle in each point. So should I use the measure tool with a step size of dp for my points list and then just add them all up?

Thank you!



  • Well, I also find this problem, how can we create new particles? It is very important.
  • We are now working on a version that includes open boundaries with inlet and outlet conditions. This new implementation will be released as open source code once we have produced and published journal papers on that.

    Meanwhile you have to implement it on your own ...

  • edited November 2017
    Hi Alex

    Thank you! I do know about that version and I am looking forward to it .Maybe I did not make myself clear. At the moment, I am looking for a way to measure the amount of particles going through a given cross section. I need to measure volume per unit of time in order to compare my results to other engineering softwares. And I'm not sure what data I should be looking to extract form the measure tool. I am also not sure what exactly what data I am getting when I get (Kcorr) from the measure tool. Is it a physical quantity?
  • New version includes a new tool to measure that called MeasureBox where you can define a box (or a thing one) and obtain info of the number of particles entering and leaving the domain at each step PLUS their velocity, so it is easy to compute inflows and outflows

  • Great! I'll be looking forward to that! Thank you
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