论文标题
偏心环的0-4度倾斜度的两相流量模拟
Two-phase flow simulations at 0-4 degrees inclination in an eccentric annulus
论文作者
论文摘要
多相流模拟在偏心的环中运行。对于外部圆柱体和内部气缸的环的尺寸分别为0.1和0.05 m，混合速度在1.2至4.2 m/s之间。将模拟与在能源技术研究所进行的完全偏心和完全同心实验进行了比较。本文的目的是探索固定分数和内部管道对压力梯度和流动状态的影响。比较表明，将管道从完全偏心转移到部分偏心构型会对压力梯度产生巨大影响。在所有情况下，内部管道从完全偏心的几何形状更改为偏心型构型，我们都会发现增加了平均压力梯度的48-303 \％。相比之下，将管道从同心移动到更偏心的构型的情况，导致压力梯度的变化较小。 2个病例在平均值，最大和最小压力梯度的实验结果的22 \％之内，而最后两例的情况分别超过了最小和平均压力梯度25-250％。我们很少观察到流动状态的变化是移动内部管道的效果。在8个水平情况中，有2个表明从波浪流到sl液流或明显更大的波浪的过渡。确定的最突出和频繁的差异是改变的sl和波频。通过模拟，我们注意到，当相平均速度相同时，压力梯度增加，伴随着固定分数的增加。对应于0.177、0.244、0.063和0.073的分数持有增加，每种相同混合物流速和网格密度的模拟压力梯度的增加分别为80、300、614和367 PA/M，或116、244、61.5和25％和25％。
Multiphase flow simulations were run in an eccentric annulus. The dimensions of the annulus were 0.1 and 0.05 m for the outer and inner cylinders, respectively, and the mixture velocities were between 1.2 and 4.2 m/s. The simulations were compared with fully eccentric and completely concentric experiments conducted at the Institute for Energy Technology. The purpose of this paper is to explore the effect of the holdup fraction and interior pipe's position on the pressure gradient and flow regime. The comparisons indicate that moving the pipe from an entirely eccentric to a partially eccentric configuration has a drastic impact on the pressure gradient. In all cases where the inner pipe was changed from a completely eccentric geometry to a less eccentric configuration, we notice an increase of 48-303 \% of the mean pressure gradient. Comparatively, cases, where the pipe was moved from a concentric to a more eccentric configuration, result in less drastic pressure gradient changes. 2 cases were within 22 \% of the experimental results for mean, max, and min pressure gradient, while the last two cases exceeded the minimum and mean pressure gradients by 25-250 %, respectively. We rarely observed a change of flow regime as an effect of moving the inner pipe; 2 out of the 8 horizontal cases indicate transition from wavy flow to slug flow or significantly larger waves. The most prominent and frequent discrepancies identified were altered slug and wave frequencies. Through the simulations, we notice that there is an increased pressure gradient accompanying an increased holdup fraction when the phase-averaged velocities were the same. Corresponding to a fractional holdup increase of 0.177, 0.244, 0.063, and 0.073, the increase in simulated pressure gradient for each case of the same mixture flow rate and mesh density was 80, 300, 614 and 367 Pa/m respectively or 116, 244, 61.5 and 25 %.
