hi, everybody,

In a 3D project, I want to show the sheath flow and sample flow by plotting their path lines. The flow is single phase but with different entrance velocities, the sheath flow is treated with constant velocity in the inlet_1 while the sample flow is treated with parabolic velocity profile in the inlet_2. After mixing, the two flows will pass through a cone part(seems like a nozzle, and the flow is laminar, Re number is about 100), and then a square part, whose end is termed as the outlet.

I can finish the computing in FIDAP and the velocity distribution in any crossing plane seems good, But here is the problem: since I use the brick mesh, so FIDAP should be able to handle the path lines, and the support engineer said yes too. But according to his statement and script file, the path lines will be outside of the geometry, which is definitely wrong; and once I give the DT value very small, the path lines in at the entrance will wave, which is not true either.

So I have to turn here to ask some experienced and knowledgabl people to help me. I can email the files to you. (I hope I can attach my files here.)

Thanks a lot.

qing hao

[sammyraj]

Hi qing ,


I am facing same problem as yours, I have to introduce two fluids( liquids) at two inlets and the geometry consists of two annular pipes in which inside pipes ends at the middle and fluid coming from it joins with the fluid coming from outside pipe and both go through a single outlet. Hope I made it clear.

Please suggest me a method to use and how to introduce two inlets especially and I have been trying to use VOF method but I am not sure I am in a correct way. and also my fluids does not mix.

..I am trying simulate a flow in cytometer and my objective is to measure the focusing width of the sample flow. I am using Ansys FLUENT as post processor.

Thank you.

.