Reply To: Low Re flow inside Microchannel

[saadbin]

1. I tried the ‘gdb’ debugger to figure out the origin (see the image here: https://drive.google.com/file/d/1O99J2tEe6WEl2TNDuoLZmfluHS2hK1iv/view?usp=sharing). From what I understand from it, the scaling error is coming from the following line inside cylinder3d.cpp:

SuperLatticeYplus3D<T, DESCRIPTOR> yPlus( sLattice, converter, superGeometry, stlReader, 5 );

This is defined inside src/functors/lattice/turbulentF3D.hh, where line 87 calls the function ‘normalize’:

normal = util::normalize(normalTemp);

-which is throwing the assertion error. Could you let me know what this line is actually doing?
And if I modify this line to not normalize, what problems should happen with the physics, because if I change it to “normal = normalTemp;” the error is not thrown anymore.

2. Currently my N is relative to the width of the channel (136 micron), not the width of the obstacle (3 micron). I am setting width of channel as charactersitic length because I am targetting a specific Knudsen number (meanfreepath/charL). As mean free path of air is constant, I was thinking I have to fix the charL to achieve my target Knudsen number. Do you think this approach is wrong? What do you suggest otherwise?

Thanks!