为了进一步揭示微气泡减阻机理,并探讨其实用化进程的影响因素,采用混合物多相流模型对平板微气泡减阻( BDR)问题进行了二维数值模拟,讨论了重力及底部和顶部2种通气方式的影响,对微气泡减阻机理进行了分析. 利用相群平衡模型( population balance model)三维数值模拟了平板底部通气和侧壁通气,对平板三维效应进行了研究. 结果表明:重力对大气泡影响较大;对于顶部通气方式,重力使气泡停留在边界层,从而使减阻效果得到改善;减阻率与气层厚度之间存在一定的关系. 侧壁通气的减阻效果不佳,三维效应也降低减阻效果.%In order to further reveal the microbubble drag reduction ( BDR) mechanism, and ascertain the factors influencing the practicality process of BDR, the two-dimensional numerical simulation was done to solve the plate BDR problem, using the mixture′s multi-phase flow model. The effects of gravity and the bottom and top ventilating modes were discussed, and the BDR mechanism was analyzed. Based on the population balance model, the ventila-ting on the bottom and on the side of the plate was respectively simulated with the three-dimensional model, and the plate′s 3D effects were analyzed. It is shown that the effect of gravity on big bubbles is larger. For the plate-on-top ventilating mode, gravity is beneficial to retaining the bubbles in the boundary layer and therefore BDR is improved. The drag reduction levels are related to the thickness of the gas layer near the plate. The drag reduction levels with plate vertical are discounted. The 3D effect also reduces the drag reduction effect.
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