Optimization Of Main Parameters Of Mud Mixing Unit Of Hub Bearing Monomer Seal Test Machine

As known,mud is an important ambient medium for Leaktightness Test of Single Hub Bearing(abbreviated as Leaktightness Test),which requires a very strict compounding ratio.Concentration and uniformity of mud depend on mixing process.In order to ensure the effectiveness of the Leaktightness Test as well as keep mud concentration following test requirement under a lower energy consumption in the mixing process,it is necessary to optimize the mixing parameters.On the paper,the mud concentration distribution in the Leaktightness Test was numerically simulated,followed by optimizing the key parameters of mud mixing through orthogonal test.The main work contents are as follows:(1)Through analyzing particle size distribution of mud particles,the sizes of mud particles were simplified by weighted average treatment.The description methods of mud concentration in general and mud concentration particularly in finite element numerical simulation were concluded.Refer to the requirements for achieving given mud concentration in a particular Leaktightness Test,requirement for standard-reaching rate of mud concentration in mud extraction area were discussed.(2)The governing equation and model of numerical simulation were introduced,that applied the Eulerian model and the standard k-? turbulence model to simulate the static settling of mud particles in the test tank.The static sedimentation experiment of mud particles in the test pool was carried our for comparison of sedimentation process of mud particles between numerical simulation and experimental observation.By analyzing the depth of clarifying area varying over time obtained from numerical simulation and experimental observation,the feasibility of the Eulerian model and the standard k-? turbulence model for the numerical simulation of mud concentration was verified.(3)Establish a finite-element-calculation model for mud mixing in the Leaktightness Test,apply multiple reference frame method in the rotate area,and apply Eulerian multiphase flow and standard k-? turbulence model to have numerical simulation of the process of mud mixing and analyze mud concentration distribution in different cross section.Then the standard mud concentration areas in various cross section were found by using post-processing software.At the end,the numerical simulation data were processed to calculate out standard-reaching rate and mixing power of the partial mud concentration in the mud extraction area.(4)Employ the standard-reaching rate and mixing power of the partial mud concentration in the mud extraction area as test indexes,and design the multi-index orthogonal test scheme for the mixing device.Through the numerical simulation results of each test scheme,the influencing rule to each test index by the main parameters of mud mixing was studied.According to the requirement of the Leaktightness Test,it is known that the importance of mud concentration compliance rate index and the mixing power index in the mud extraction area are different.As a result,a dual index comprehensive scoring standard was provided to comprehensively rate the orthogonal test results,then obtain the optimization results of the key parameters of the mixing device as: 250 mm length of blade at 150 mm height over ground at stirring speed of 120 r/min.It was verified by numerical simulation that under this set of parameters,the standard-reaching rate of mud concentration in the mud extraction area satisfied the standard requirement for extracting mud under minimum energy consumption.The research results of optimization of key parameters of mud mixing unit for leaktightness test of single hub bearing can provide theoretical basis for the design of mud mixing unit for the leaktightness test of single hub bearing,so as to ensure the its effectiveness.