Hi, all:

I tried to simulate a incompressible laminar flow inside a rectagular micorchannel(cross section dimensions: 54um X 25um). It should be very simple, here is what I did in my work:

1). I used laminar solver in FLUENT; 2). I used boundary layer mesh in the near wall region that I am interested in; 3). I used pressure inlet and pressure outlet for boundary conditions.

The calculation can converge well. However, if I compare the results to those predicted from analytical solution, the results from FLUENT is far bigger.

I am wondering if somebody did similar work before and got such results before. Do you think that FLUENT can handle flow in so small dimensions?

Thanks a lot,

Jeremy.

Hi,

It looks like the flow is sufficiently larger than the Knudsen number range, so all equations of continuum are applicable and Fluent can handle it pretty well. What you would need to do is check the reference values, you might be referencing your result incorrectly. If possible use a Hydraulic diameter for your rectangular c/s and then use the Poisuelle equation to compare the results of Fluent. Hope this helps. Aravind

[Trudix]

Hi guys,
I have a similar problem. In my simulation of an rectangular pressure-driven microchannel 3x4x300 microns I won"t get convergent results in my mesh sensitivity analysis. So I was thinking that it might be due to my inflationlayer-thickness. Is there a way to calculate the y+ for a pressure driven flow since I have no information about the flow-velocity. I only know the geometry, density, viscosity and pressuredrop (pressure values at in- and outlet). The flow is stationary and incompressible.

Your help is very much appreciated.

Thank you