Hi Everybody,

I am an engineer working for an industrial company and I am currently researching on available CFD codes in the market for the problem of air-flow between a pair of co-rotating disks in a HDD. I have good experience in developing my own code by I have little knowledge about the commercial codes in the market. I have heard of Fluent, which is said to be the best, and PowerFlow, which incorporates Lattice-Boltzman method. Does anybody know whether Lattice-Boltzman method is as efficient as the traditional method (solving discretized forms of N-S equations) in capturing flow phenomena? What are the advantages and disadvantages of Lattice-Boltzman method compared to the traditional method. I would really appreciate your help in this regard.

Regards Mohammad

Advantages of the LBM is that it is good for complecated geometries such as porous material. And it is mesoscale, so it may be good to use LBM in HDD simulation, because the thin region between the disk, N-S equations may not be valid, instead you may use kinetic based LBM.

Mohammad,

You should look into a former CML student's thesis:

A Study of Rarefied and Contact Air Bearing Modeling for Hard Disk Drives Using the Direct Simulation Monte Carlo Method, Weidong Huang, Doctoral Dissertation, December 1998.

Found a link to the paper:

http://www.algarcia.org/Pubs/Slider3D97.pdf

In the mesoscale field£¬LBM should be a good selection.

But in the field of macro-flow, I think LBM is not better than traditional CFD method like FEM or FVM. Only one advantage, it has a feature of rotating invariant, which is a very good characteristic for flow with abundant vortexes.