How to measure Reynolds number for two phase flow in DPM(Discrete Phase Model)

sandeepjaggarapusandeepjaggarapu Member Posts: 4
edited February 22 in Fluid Mechanics

Hello Ansys Community,

I am solving a two-phase flow problem using DPM(Discrete Phase Model) in ANSYS Fluent. The two-phases are lubricating oil and air. The problem is that I need to input whether it is laminar or turbulent. In order to do that, I need to find the Reynolds number.

For this two-phase flow how to measure the Reynolds number and as of DPM is concerned for what range we can consider the flow is turbulent or laminar (because Reynolds number considered for the DPM model is different from the regular one)? Here I'm solving the problem for a simple pipe of 5mm diameter and 20mm length with a velocity of 6m/s. The density of oil is 954 kg/m3.

Thanks in advance.

Best Answers

  • RobRob UKPosts: 9,749Forum Coordinator
    Accepted Answer

    With 1% oil by volume I'd calculate Re assuming the pipe is just air. There may be a modification in a text book somewhere, but as we're just after a number to decide which model to use it's less critical.

  • YasserSelimaYasserSelima Posts: 949Member
    Accepted Answer

    Calculating Dimensionless parameters for two phase flow is always a tricky part. The majority of experimental publications use the homogenous density and velocity ... this basically because it is easier to measure/calculate. However, when possible, the actual flow parameters are better in comparison.

    So, check the references you are using, if everyone uses the homogenous density, velocity .. you need to follow. If you find discrepancy, do the right thing.


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