Flow simulation around double cylinders based on Lattice Boltzmann method at low Reynolds numbers

Air filters with low pressure drop and high efficiency are critical for the performance of industrial ventilation system. In order to manufacture air filters with optimal structure, study on flow field characteristic inside the fibrous media is essential. The flow around single cylinder and double cylinders by Lattice Boltzmann method was simulated at low Reynolds number (Re <= 1). Results showed that the degree of interference differs with different clearance ratios and arrangements. For serial cylinders, the drag coefficient of the downstream cylinder is less than the upstream, but the change amplitude is greater. The wake effect of upstream cylinder disturbs the downstream cylinder, which has the largest impact when 5 <= L/D <= 7. The value of C-d/C-d* for parallel cylinders increases with the clearance ratio. The greater the Re value is, the larger the value of C-d/C-d* will be. This study provides an optimal manufacturing direction of fibrous media for good indoor air quality.