基于离散元法苜蓿压扁调制过程仿真分析与试验

Simulation analysis and experiment of alfalfa flattening modulation process based on discrete element method

为研究苜蓿压扁调制机构工作参数对作业性能的影响,采用离散元模拟对基本参数进行优化。基于理论分析,以苜蓿压扁率和压扁损失率为考核指标,采用EDEM软件分别对喂入量、调制辊转速和调制辊间隙作单因素模拟试验,结合模拟试验结果,开展Box-Behnken三因素三水平响应曲面仿真试验研究并对回归模型进行多目标优化。结果表明,各因素对苜蓿压扁率、压扁损失率影响显著性由大到小分别为喂入量、调制辊间隙、调制辊转速和调制辊间隙、喂入量、调制辊转速;最佳工作参数组合为:喂入量2.9 kg·s^(-1)、调制辊转速694 r·min^(-1)和调制辊间隙3.7 mm,此时苜蓿压扁率为94.45%、压扁损失率为3.27%,将最优参数通过台架验证试验,测得试验结果与模型优化值相对误差小于3%。研究结果可为相关机具设计和优化提供数据参考和理论依据。

In order to study the influence of working parameters of alfalfa flattening modulation mechanism on working performance,the basic parameters were optimized by discrete element simulation.Based on the theoretical analysis,the flattening rate and flattening loss rate of alfalfa were taken as the evaluation indexes,and the single factor simulation experiments were carried out by using EDEM software to simulate the feeding amount,the speed of the modulation roll and the gap of the modulation roll,respectively.Combined with the simulation experimental results,the Box-Behnken threefactor and three-level response surface simulation experiments were carried out and the regression model was optimized by multi-objective.The results showed that the significant effects of each factor on alfalfa flattening rate and flattening loss rate from large to small were feeding amount,modulation roll clearance,modulation roll speed and modulation roll clearance,feeding amount and modulation roll speed,respectively.The optimal working parameter combination was as follows:feeding amount of 2.9 kg·s^(-1),modulation roll speed of 694 r·min^(-1) and modulation roll clearance of 3.7 mm.At this time,alfalfa flattening rate was 94.45%and flattening loss rate was 3.27%.The optimal parameters were verified by bench test,and the relative error between test results and model optimization value was less than 3%.The research methods and results could provide data reference and theoretical basis for the design and optimization of related machinery and tools.