农业工程学报
農業工程學報
농업공정학보
2014年
8期
40-48
,共9页
石林榕%吴建民%孙伟%张锋伟%孙步功%刘全威%赵武云
石林榕%吳建民%孫偉%張鋒偉%孫步功%劉全威%趙武雲
석림용%오건민%손위%장봉위%손보공%류전위%조무운
农业机械%数值方法%优化%排种器%离散单元法
農業機械%數值方法%優化%排種器%離散單元法
농업궤계%수치방법%우화%배충기%리산단원법
agricultural machinery%numerical methods%optimization%seed metering device%discrete element method
为了优化水平圆盘式精量排种器的最佳排种性能参数(动排种盘转速、动排种盘厚度、型孔圆角半径),达到提高粒距合格指数、降低漏播和重播指数指标,并降低大田试验强度。该文基于离散单元法对根据全膜双垄沟播技术所设计的水平圆盘式精量排种器进行了排种数值模拟,并得到玉米籽粒模型排种、重播、漏播的形成过程;为提高其排种性能,进行了排种仿真试验。仿真结果表明:以合格指数较高为重点、兼顾重播指数和漏播指数较低的原则,确定了动排种盘转速为17 r/min、动排种盘厚度为6 mm、型孔上边倒圆角半径为1 mm时为较优组合,此时粒距合格指数S=97.05%、重播指数D=1.83%、漏播指数M=1.12%。田间验证试验表明:在上述条件下,测得粒距合格指数为S=95.13%,重播指数D=2.34%,漏播指数M=2.53%,重点指标粒距合格指数误差2.02%(<5%)。因此,基于离散单元法的排种器仿真试验为排种器性能参数的确定提供参考。
為瞭優化水平圓盤式精量排種器的最佳排種性能參數(動排種盤轉速、動排種盤厚度、型孔圓角半徑),達到提高粒距閤格指數、降低漏播和重播指數指標,併降低大田試驗彊度。該文基于離散單元法對根據全膜雙壟溝播技術所設計的水平圓盤式精量排種器進行瞭排種數值模擬,併得到玉米籽粒模型排種、重播、漏播的形成過程;為提高其排種性能,進行瞭排種倣真試驗。倣真結果錶明:以閤格指數較高為重點、兼顧重播指數和漏播指數較低的原則,確定瞭動排種盤轉速為17 r/min、動排種盤厚度為6 mm、型孔上邊倒圓角半徑為1 mm時為較優組閤,此時粒距閤格指數S=97.05%、重播指數D=1.83%、漏播指數M=1.12%。田間驗證試驗錶明:在上述條件下,測得粒距閤格指數為S=95.13%,重播指數D=2.34%,漏播指數M=2.53%,重點指標粒距閤格指數誤差2.02%(<5%)。因此,基于離散單元法的排種器倣真試驗為排種器性能參數的確定提供參攷。
위료우화수평원반식정량배충기적최가배충성능삼수(동배충반전속、동배충반후도、형공원각반경),체도제고립거합격지수、강저루파화중파지수지표,병강저대전시험강도。해문기우리산단원법대근거전막쌍롱구파기술소설계적수평원반식정량배충기진행료배충수치모의,병득도옥미자립모형배충、중파、루파적형성과정;위제고기배충성능,진행료배충방진시험。방진결과표명:이합격지수교고위중점、겸고중파지수화루파지수교저적원칙,학정료동배충반전속위17 r/min、동배충반후도위6 mm、형공상변도원각반경위1 mm시위교우조합,차시립거합격지수S=97.05%、중파지수D=1.83%、루파지수M=1.12%。전간험증시험표명:재상술조건하,측득립거합격지수위S=95.13%,중파지수D=2.34%,루파지수M=2.53%,중점지표립거합격지수오차2.02%(<5%)。인차,기우리산단원법적배충기방진시험위배충기성능삼수적학정제공삼고。
In order to optimize the best metering parameters on the performance of horizontal disc precision metering device (The rate of moving metering plate, thickness of moving metering plate, fillet radius of type hole), a simulation model of horizontal disc precision metering device was designed with Solidworks. The average size of Gansu common 3 corn grains were reported in statistics, namely the length is 10.86 mm, and the width is 7.22 mm, and the thickness is 5.12mm. In accordance with which the model of corn grain was designed with the use of slice modeling techniques, and using the spherical particles aggregation method the discrete model of corn grain was established. Poisson’s ratio, shear modulus and density of corn were determined by test. Namely poisson’s ratio is 0.357, and shear modulus is 2.6 MPa, density is 1 250 kg/m3. To increase the qualified index of seed space and reduce the replay and miss-seeding index, and depress the intensity of field test, on the basis of DEM dynamic simulation metering experiment of horizontal disc precision metering were conducted. Experimental results show:with higher the qualified index of seed space as the key point and taking lower the multi-seed index and the no-seed index into consideration, the bigger the qualified index of seed space is better, and the smaller the multi-seed index and the no-seed index is also better. Variance analysis showed the factor A, B and C had conspicuous effect on the qualified index of the seed space S, and the factor B had conspicuous effect on the multi-seed index D, and the factor A and C had significant influence on the no-seed index M, the factor B, interaction between A factor and C factor had a conspicuous effect on the no-seed index M. The speed of the moving metering plate is 17 r/min and the thickness of the moving seed metering plate is 6mm and the fillet radius of the type hole is 1 mm, was selected as an optimal combination. Under the conditions, the qualified index of seed space was 97.05%, and the multi-seed index was 1.83%, and the no-seed index was 1.12%. The optimized parameters of the simulation experiment were verified in the test trial. Field test results showed: under the conditions, the qualified index of the seed space was 95.13%, and the multi-seed index was 2.34%, and the no-seed index was 2.78%. In comparison with the simulation results, the error of the qualified index of the seed space was 2.02%. Therefore, simulation test of the horizontal disc precision metering device has certain guiding significance to develop the performance of the metering parameters device. It provided a reference method for optimizing the other types of precision metering.