基于四参数流变模式的旋流分离流场特性分析

利用四参数流变模式描述钻井液的非牛顿流动特性，结合雷诺应力模型(RSM)，研究钻井液非牛顿性对旋流分离流场的影响. 得到3种流体介质的速度场和压力场分布规律. 结果表明，流场模拟结果与实验结果吻合，模拟结果可靠. 虽然3种流体流场分布趋势相同，但同一位置非牛顿流体的静压力(4.02和3.77 MPa)和轴向速度(11.9和12.4 m/s)大于牛顿流体(3.22 MPa和11.7 m/s)，切向速度(42.5和39.7 m/s)小于牛顿流体(47.5 m/s)；四参数流体的静压力(3.77 MPa)和压力降(4.51 MPa)小于幂律流体(4.02和4.79 MPa)，能量损失降低0.28 MPa，四参数流体的切向速度比幂律流体小2.8 m/s，且其零轴速包络面更靠近器壁，不利于流体介质分离.

Analysis on Flow Field of Hydrocyclone Separation Based on Four-parameter Rheological Model

A four-parameter rheological model was used to describe the non-Newtonian flow characteristics of drilling fluid, combining with Reynolds stress model, the influence of non-Newtonian behavior on the flow field of hydrocyclone separation was examined, and the distributions of velocity and pressure fields of three kinds of fluid were obtained. The results showed that the flow field simulation results were in accordance with the previous experimental results, indicating that the simulation was were reliable. Their fluid flow field distributions were similar, but at the same position, the static pressure (4.02 and 3.77 MPa) and axial velocity (11.9 and 12.4 m/s) of non-Newtonian fluid were greater than those of Newtonian fluid water (3.22 MPa and 11.7 m/s), and the tangential velocity of non-Newtonian fluid (42.5 and 39.7 m/s) was less than that of Newtonian fluid water (47.5 m/s). Compared with power law fluid, the static pressure of four-parameter rheological fluid decreased from 4.02 to 3.77 MPa and the pressure drop from 4.79 to 4.51 MPa, the energy loss was reduced by 0.28 MPa, while the tangential velocity was decreased by 2.8 m/s and the envelope of zero vertical velocity was closer to the wall, which was not conducive to the separation of fluid media.