基于离散元的双轴旋耕机功耗预测模型

Prediction Model of Double Axis Rotary Power Consumption Based on Discrete Element Method

针对双轴旋耕机结构参数复杂、功耗高,受耕作时节限制,难以用田间试验的方法进行减阻降耗研究的问题。基于离散元法,构建双轴旋耕秸秆土壤耕作模型,研究了双轴配置参数对功耗的影响,通过响应面试验分析,建立了功耗的数学预测模型。模型优化的结果表明,当前后刀轴回转半径均为195 mm,后轴相对于前轴垂直距离为99.8 mm,前后轴回转圆水平距离为100.6 mm,获得的功耗最小为9.018 kW。为了验证功耗模型的准确性,在固定工作参数下,进行了原尺度整机仿真试验和田间试验。试验结果表明:真实原尺度旋耕机的田间试验功耗与整机仿真值误差均值为9.5%,范围为5.8%~13.4%,结合响应面分析说明功耗数学预测模型较为准确,表明旋耕机刀组在缩放过程中误差变化较小,模型能够准确反映双轴配置参数对双轴旋耕机在稻茬田地作业功耗的影响。

In view of the high power consumption of the double axis rotary cultivator,it is difficult to carry out research on drag reduction and consumption reduction only by the method of field trials because of the complex structural parameters and the high manufacturing cost of the equipment.Based on the discrete element method,a biaxial rotary tillagestrawsoil tillage model was constructed,the influence of biaxial configuration parameters on power consumption was studied,and a mathematical prediction model for power consumption through response surface test analysis was established.The optimization results of the model showed that the gyration radius of the front and rear tool shafts was 195 mm,the vertical distance of the rear shaft relative to the front shaft was 99.8 mm,the horizontal distance of the front and rear shaft gyration circle was 100.6 mm,and the minimum power consumption obtained was 9.018 kW.In order to verify the accuracy of the power consumption model,under fixed operating parameters,a full-scale simulation test and a field test were carried out.The test results showed that the field test power consumption of the real original scale rotary cultivator and the simulation value of the whole machine were 9.5%,and the range was 5.8%~13.4%.Combined with the response surface analysis,it was showed that the mathematical prediction model of power consumption was more accurate,indicating that the error of rotary cultivator model was small during the scaling process,and the model can accurately reflect the influence of the dual-axis configuration parameters on the power consumption of the double axis rotary tiller in the rice stubble field.