水合物螺旋流输送衰减规律数值模拟研究

Numerical Simulation of Decay Law of Hydrate Swirl Flow

为了提高螺旋流对水合物的安全输送边界,利用数值模拟技术对影响螺旋流衰减的因素进行研究。结果表明,水合物颗粒的旋转方向与扭带扭转方向相同,且扭率Y越小Re越大,对称涡线发生合并的位置越远。初始旋流数的大小主要与扭率Y有关,而与Re无关。但是在无扭带的管道下游螺旋流迅速呈指数规律衰减,其衰减速率主要与Re有关,而与扭率Y大小无关。并得出螺旋流衰减指数β与Re的关系式。与光管相比,螺旋流能够明显提高水合物的输送距离,在螺旋流较强段水合物颗粒均匀分布在管壁四周。

In order to improve the safe transport boundary of the swirl flow to hydrates, the numerical simulation technology is used to study the factors that affect the decay of swirl flow. The results show that the rotation direction of the hydrate particles is the same as the torsional direction of the torsional band. What’s more the smaller the torsion Y is, the larger the Reynolds number is and the further the position of the symmetric vortex line merging. The magnitude of the initial swirl number is mainly related to the torsion rate Y, and is independent of Reynolds number. However, the spiral flow in the downstream of the pipe is yield to an exponential decay. Its decay rate is primarily dependent on the magnitude of the Reynold number and is independent of the magnitude of the torsion rate Y. And the relationship between the attenuation index beta of the spiral flow and the Reynolds number is obtained. Compared with the light tube, the spiral flow can obviously improve the transport distance of the hydrate, and the hydrate particles in the stronger spiral flow are evenly distributed around the wall of the tube.