AN EVALUATION OF THE BOUNCE-BACK BOUNDARY CONDITION FOR LATTICE BOLTZMANN SIMULATIONS
✍ Scribed by Martha A. Gallivan; David R. Noble; John G. Georgiadis; Richard O. Buckius
- Publisher
- John Wiley and Sons
- Year
- 1997
- Tongue
- English
- Weight
- 321 KB
- Volume
- 25
- Category
- Article
- ISSN
- 0271-2091
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✦ Synopsis
The bounce-back boundary condition for lattice Boltzmann simulations is evaluated for ¯ow about an in®nite periodic array of cylinders. The solution is compared with results from a more accurate boundary condition formulation for the lattice Boltemann method and with ®nite difference solutions. The bounce-back boundary condition is used to simulate boundaries of cylinders with both circular and octagonal cross-sections. The convergences of the velocity and total drag associated with this method are slightly sublinear with grid spacing. Error is also a function of relaxation time, increasing exponentially for large relaxation times. However, the accuracy does not exhibit a trend with Reynolds number between 0Á1 and 100. The square lattice Boltzmann grid conforms to the octagonal cylinder but only approximates the circular cylinder, and the resulting error associated with the octagonal cylinder is half the error of the circular cylinder. The bounce-back boundary condition is shown to yield accurate lattice Boltzmann simulations with reduced computational requirements for computational grids of 1706170 or ®ner, a relaxation time less than 1Á5 and any Reynolds number from 0Á1 to 100. For this range of parameters the root mean square error in velocity and the relative error in drag coef®cient are less than 1 per cent for the octagonal cylinder and 2 per cent for the circular cylinder. # 1997 by