Research On Four-piece Open Turbine Blade Based On Flow Field Simulation And Experiment

The pre-mixer is one of the key equipment for solid propellant production,and the stirring blade is the core component of the pre-mixer.The flow filed of the solid-liquid fluid in the stirred tank is determined by the geometry shape and structure parameters of the blade.The traditional stirring blade design is calculating the surface from table of offsets,but for the mixing of the solid-liquid flow with higher solid content and higher viscosity in the premixing process,new technical requirements are put forward for the shape and structural parameters of the stirring blade.This paper takes the four-piece open turbine blade as the research object,takes the mixing effect of solid-liquid fluid in the stirred tank as the evaluation index,and studies the structural design and optimization of the blade from two aspects: numerical simulation and experimental verification.The main research contents of this paper are as follows:Firstly,a scheme design for evaluating the effect of pre-mixed solid-liquid two-phase mixing is proposed.According to the pre-mixed process and the material characteristics of the substitute materials,the stirring fluid system is abstracted into a solid-liquid two-phase flow system of sand-MTPB,and the evaluation indexes of the solid-liquid mixing effect are determined as the stirring power,mixing capacity and comprehensive efficiency.Then,the effect of blade structure parameters: blade oblique angle,blade width,blade diameter and the height of the blade from the bottom to the mixing effect evaluation index is analyzed and the orthogonal test method(four factors and three levels)to find the primary and secondary relationship of the factors that influence the mixing effect.Secondly,a numerical model of the solid-liquid two-phase flow in the stirred tank was established and simulated.Using the stirring power,mixing capacity and comprehensive efficiency as the evaluation indexes,the numerical simulation results were analyzed by the range analysis method,and the primary and secondary relationship and the optimal level combination of the influence of the blade parameters on the evaluation indexes were obtained.Then,the velocity field and concentration field in the stirred tank under the action of the blade were compared and analyzed,and the dispersion mechanism of sand particles in the stirred tank was studied.Finally,a stirring experiment platform for the solid-liquid system was built and a verification experiment was carried out.Comparing the experimental results with the numerical simulation results,the results show that under the same evaluation index,both the experiment and the numerical simulation have obtained the same primary and secondary relationship of factors and the optimal level combination.It shows that the optimal structure parameters of the blade obtained in this study are credible,and it is feasible to optimize the design of the blade structure by numerical simulation through the Euler multiphase flow model.This article provides a reliable method for the optimization and amplification design of the blade structure.