Optimization Of Structural Parameters And Flow-field Simulation On Mixing Drum Of Mining Concrete Transport Vehicle

Mining concrete transport vehicle can be used as concrete transportation in a low environment such as mine;tunnel and national defense projects because of the vehicle dragged by rail locomotive which has the characteristics of low vehicle height.The mixing drum is the main working parts of the transport vehicle.In this dissertation,aiming to solve the problems existing in current transport vehicles,such as short life,large energy consumption and slow discharge speed,the modern design method is used and based on the existing parameters of the 2m3 mine truck to improve the original design.The dissertation mainly includes following four parts:(1)The overall scheme design of 2m3 mining concrete transport vehicle is completed through selecting and determining the working parameters and structural parameters.Utilizing 3D design software to design the mainly 3D parts modeling of the mining truck and conduct the assembly modeling.In this article,two-dimensional engineering drawing design and prototype manufacture are completed.(2)The mathematical expression between structural parameters and driving resisting torque for mixing drum under the maximum load is deduced by calculus.With the goal of the minimum driving resisting torque,the sofeware of MATLAB is used to optimize the working parameters of mixing drum.Furthermore,the CFD software was applied to analyze the inner flow field of mixing drums before and after optimization,as well as to compare and verify the optimal method and the correctness of the simulation results.The results showed that the driving resisting torque of mixing drums after optimization was decreased by 14.7%.(3)Statically analysis of the working process of breaking and unloading was done by using the software of ANSYS Workbench,and according to the simulation,the role of force and deformation in different cases was obtained.Taking the mixing drum mass as an object,the main parameters and structure were optimized.Solved the problems of supporting roller damage and weld cracking at the position of the front panel and front cone in the mixing drum by the measures of improved the strength of the weld and quick-wear parts.Compared with original design,the mass of the mixing drum was reduced by 14.02%,the maximum equivalent stress of quick-wear parts reduced by 20.79% and the strength of mixing drum improved by 17.33%.(4)To study the shape of mixing helical vane and the speed of mixing drum influence on its working performance,obtain the distribution of velocity and pressure field in the mixing drum at two typical conditions for discharging and mixing process.Utilizing fluid dynamic software simulates the above discrete cases,quantitative analysis the concrete segregation degree in the mixing drum.Influence of main parameters of the blade and the stirring drum speed for discharging speed and the degree of segregation of concrete by means orthogonal tests was studied.Simulation results demonstrate that the spiral angle of the blade of the back cone has the greatest impact on the discharging speed of the mixing drum and the speed of mixing drum has the greatest influence concrete segregation degree in the mixing process.The optimized blade structure parameters: helix angle of blade at the mixing drum’s back cone section1? =65°,helix angle of blade at the mixing drum’s cylindrical section2? =70°,helix angle of blade at the mixing drum’s front cone section3? =72°,setting angle of blade at the mixing drum’s ? =82.5°;The optimized speed parameter of mixing drum in the working condition: mixing process2 v =0.7rpm,discharging process1 v =9rpm.