【摘要】 应用二维激光多普勒仪(LDV)对一种单柱单锥型液-液旋流分离管内流场进行了测量,考察了流量、溢流比、压力比和气芯等参数对流场的影响。测量结果表明:切向速度分布呈典型的Rankine涡结构,沿轴向衰减很少,表明所用锥角是合适的;因该旋流管的水力直径较大,切向速度的总体水平较低,由此对了离特性带来不利影响。此外,没有观察到切向速度分布的双峰分布现象。轴向速度的总体水平较低,尤其是在锥形管的上游更为明显,这既有助于增加液流在旋流管中的停留时间,改善了离特性,也有利于降低压力损失,改善旋流管的低阻特性;雷诺应力总体上呈近轴与近壁处大,其它区域中小的分布趋势;上游的轴向正应力大于切向正应力,而下游的切向正应力又大于轴向正应力,表明其中湍流的各向异性特性;在所考察的四种工况因素中,以流量的影响范围和程度最大,压力比、溢流比及气芯的影响仅表现在近轴区中。更多还原

【Abstract】 The detailed flow field in a liquid liquid hydrocyclone with a single cylinder and a cone has been measured using a 2 D LDV. The effect of different flow parameters, such as overflow ratio, pressure ratio, flow rate and air core on the flow field has been studied. The results show that the tangential velocity profiles have a typical Rankine vortex structure: solid body body rotation plus free vortex, and change slightly along the axial directon. This indicates that the adopted cone angle is suitable. Since this geometrical configuration has a large hydraulic diameter, all the tangential velocities are kept in a low level, so the separation performance is not good enough. The double peaks in tangential velocity profiles are not observed. As for the axial velocity, both the upward and downward axial velocities in the near axis and near wall regions are in a low level, especially near the inlet region. This is helpful for increasing the resident time and decreasing the pressure drop. The Reynolds stresses have higher values near the axis and near the wall. The axial normal Reynolds stress is greater than the tangential one in the upstream region and is smaller than the tangential one in the downstream region. So the turbulence in the hydrocyclone is anisotropic. Compared with the effect of other flow parameters, the effect of the flow rate is greatest both in its range and extent. The influence of other factors is limited only in the near axis region.更多还原