MP-PIC investigation of the multi-scale gas-solid flow in the bubbling fluidized bed

Numerical study of the dense gas-solid flow in a bubbling fluidized bed has been conducted via the multiphase particle-in-cell approach. Based on the numerical results, the mesoscale bubble dynamics combined with the particle-scale information of gas-solid phase are explored to understand the multi-scale flow property of the gas-solid phase in this apparatus. Several tips regarding the multi-scale gas-solid flow can be obtained as: (i) Bubble volume in the bed behaves with a log-normal distribution pattern and the largest bubble appears in the central part of the bed. (ii) The horizontal chord length of bubbles is the largest in the central region but small near the wall. Large vertical chord length of bubbles exists near the bed wall. (iii) Elongation of the rising bubbles in the upper part of the bed enlarges the aspect ratio. Large aspect ratio and small pressure of the bubbles appear near the bed wall. Bubble pressure decreases along the bed height. (iv) Large particle Reynolds number can be observed in the dome and tail of the bubbles while small value appears at both sides of bubbles. The operating parameters alter the bubble dynamics and also the particle-scale information of solid phase.