两种导叶设计方法对液-液旋流器的流场影响的数值模拟

为了高效低阻地处理油水分离后产生的含油污水,采用两种不同方法(气动法和几何法)设计了液-液旋流器的导叶结构。并利用Fluent软件对两种结构的旋流器内流场进行模拟,着重分析了旋流器内速度场、压力场以及剪切强弱。结果表明气动法导叶的旋流器相较于几何法导叶的旋流器具有以下特点:切向速度和轴向上行速度峰值较大,导叶对流体的控制性好,无脱流现象产生;静压的径向压力梯度较大,但总压的轴向压降较低,即能耗较低;湍流强度较低,剪切应力峰值略高。因此气动法导叶的加速和控制流体转向能力较好,可以产生较大的离心力,同时产生的湍流场各向异性较弱,有利于降低液滴破碎的可能性,提高分离效率,具有较好的应用前景。

Numerical Simulation of the effect on flow field of two different methods of guide vanes in liquid-liquid cyclones

For the sake of high efficiency and low resistance of processing oily sewage, two guide vane structures of axial-flow liquid-liquid cyclones are designed by using different methods. The software of Fluent is used to simulation the flow field inside the axial-flow liquid-liquid cyclones, to focus on the analysis of the velocity distribution, the pressure drop and the shear stress distribution. The results show the cyclone with aerodynamic method designed guide vane had following characteristics, comparing to the cyclone with geometrical method designed guide vane: the peak of tangential velocity and axial upstream velocity are both larger, and the guide vane can control the fluid well and no fluid separation appearing on the surface of the guide vane; the radial pressure gradient of the static pressure is larger, and total pressure drop is lower, that is the energy consumption is low; the turbulence intensity is lower, but the peak of shear stress is slightly larger. So the aerodynamic method designed guide vane can accelerate and control the fluid well, so the centrifugal force is larger, meanwhile the anisotropism of turbulent flow is weaker which can reduce the possibility of the droplet breakage and improve the efficiency of separation. Above all, the aerodynamic method designed guide vane has a very good prospect.