Mechanism And Kinetics Of Oil Purification Under Centrifugal Force Field With Fluent

Hydraulic system is widely used in engineering machinery,general machinery,petrochemical machinery,aerospace and other fields,but it will break down or even scrap when the contamination degree of working hydraulic oil exceeds the standard.For example,about 30% of aircraft failure is caused by the contamination of hydraulic oil.The disc centrifuge is a separator that separates the components with different density from each other depend on centrifugal principle.It has the advantages of large separation factor,continuous operation,easy operation and automatic control,and it can also separate solid particles,air,moisture and other impurities in hydraulic oil at the same time.Therefore,it is of great practical significance for flight safety and production safety to study the motion law of fluid in centrifugal force field and produce qualified oil purifier.Firstly,the solid structure of the drum is simplified to a flow field model with only fluid field and boundary conditions,and the simplified model is further processed,which includes: the inlet and outlet of oil are equivalent to a whole surface with the same area respectively;and the whole three-dimensional drum area is generated into structured mesh from the surface mesh by means of periodic boundary,2D block conversion to 3D block,periodic display and so on;besides,the disk wall is set to a rotating motion boundary without slip relative to the fluid.Then,the flow fields under five different rotational speeds,six different clearance values and six different disc cone angles were simulated,and the variation of flow field in the drum with single motion parameter was analyzed.The main contents are as follows: the distribution of circumferential velocity,axial velocity,radial velocity,static pressure and dynamic pressure of the whole flow field at different rotational speeds,and the variation of axial and circumferential velocity of disc clearance between 1 and 10 layers at 38.5mm rotational radius with different rotational speed;meanwhile,the law of tangential velocity and dynamic pressure deviating from the theoretical values with the change of clearance,and the rule of circumferential velocity of different layer clearance at the turning radius of 48.5mm;moreover,the distribution point diagram of circumferential velocity and distribution law of dynamic pressure in the drum with the change of disc cone angle.According to the simulation results,the optimal initial working speed,disc clearance and disc cone angle of the prototype are selected.Finally,not only the structure test,sealing test and running smoothness test of the prototype are carried out,but also the docking test is completed by connecting the prototype with the hydraulic system and pressure gauge of different aircraft in series.It is proved that the centrifugal separation effect of the purifier is better and the pollution degree of the oil product is reduced by at least one grade.