Measurement and analysis on reducing adhesion and resistance of bionic ripple opener

Abstract: Traditional furrow openers are lack of the ability of reducing resistance and clay adhesion. Hence, a kind of new bionic opener was designed and manufactured here based on characteristics of adhesion and resistance reduction of soil animals and ultra-high molecular weight polyethylene. Its tractive resistance was tested and compared with that of a traditional opener in an orthogonal (three factor and four level) designed field experiment in order to study the viscosity drag reduction mechanism of the bionic opener with non-smooth surface. Experimental results showed that clay adhesion on the traditional opener was not found when soil humidity was less than 16.3%, but obvious when soil humidity was more than 20.8%, while the adhesion on the bionic opener was little regardless of soil humidity. The tractive resistance of the bionic opener increased with increasing soil humidity when soil humidity was in a certain range. It was apparent that the traction resistance was mainly affected by the trenching depth, the soil humidity, and the forward velocity. Based on the related theory, the only velocity magnitude changes and the tractive resistance should be unaffected when the tractor is in a state of uniform motion. The impact of forward velocity on traction resistance and clay adhesion might because a number of conditions could not be completely controlled during the field test. In conclusion, the bionic opener was better in reducing adhesion and resistance than the traditional openers probably because: 1) the contact area with soil was smaller in the former than in the latter; 2) the former had corrugated non-smooth shape, which could form a cavity when contacting with the soil, result in a higher normal adhesion than tangential adhesion, destroying the adhesion interface and reducing the resistance; and 3) the former could cause larger stress fluctuation than the latter, and the fluctuation could partly destroy the continuity of the soil so that the barricade blocking and compaction were not easily formed. Furthermore, the bionic opener could work best in an optimal condition with soil moisture of 16.3%, the trenching depth of 6 cm and the forward velocity of 1.8 km/h.