Structural parameter optimization of a furrow opener based on EDEM software

To reduce the ditching resistance of a furrow opener during operation,single-factor and multiple-factor combinations were used to explore the influence of the furrow opener’s advance speed,blade opening angle,and width on the ditching resistance based on the discrete element method(DEM).A DEM simulation of the furrow opener was developed.Upon changing these influencing factors,the parameters with the least resistance to operation were identified.Furrow openers were fabricated according to the optimized results,and soil trench tests were carried out.Simulations and soil groove tests showed that the minimum ditching resistance was 58.54 N when the current advance speed was 4.47 m/s,the blade opening angle was 32.02°,and the furrow opener width was 51.45 mm.The error between the simulated value of the ditching resistance and the soil trench test was within 10%,and the trends of resistance change were essentially the same,indicating that it is feasible to optimize the structural parameters of a trench furrow opener using DEM.These research results can provide a reference for the parameter optimization of furrow openers.

Effects of key design parameters of tine furrow opener on soil seedbed properties

The structural parameters of tine furrow openers have significant effects on soil property of seed furrow in no-till planting,thereby affecting crop growth and yields.In order to analyze the effects of key parameters of tine furrow openers on soil properties(soil bulk density,soil water-stable aggregates(WSA),and soil disturbance)of the surface soil layer of 0-10 cm and surface straw disturbance,the tine furrow openers with different structural parameters,including cutting edge thickness,cutting edge curve,penetration clearance angle and rake angle,were designed and tested under no-till conditions.Orthogonal test and single factor test were performed to analyze the effects of different parameters.Results showed that the rake angle,cutting edge thickness and cutting edge curve had significant effects on cross-sectional area of furrow(Af)and disturbance of surface straw;the rake angle had a significant effect on soil bulk density.Soil types and operating depth had significant effects on soil disturbance caused by tine furrow openers.The concave type tine furrow opener produced the lowest soil disturbance and soil bulk density of seed furrow,the highest surface straw disturbance and the greatest content of WSA(>0.5 mm).With increasing rake angles of tine furrow opener,the width of seedbed(Wsb)and the Af decreased first and then increased,respectively,while the width of soil throw(Wst)and the height of ridge(Hr)increased.The Wsb and Af created by tine furrow opener with 60°rake angle were significantly lower than that with others,respectively.The tine furrow opener with rake angle ranged from 45°to 60°created the lowest soil bulk density.As the penetration clearance angle increased,the content of WSA(>0.5 mm)decreased,but the effect of penetration clearance angle on the content of WSA(<0.5 mm)was not significant.The cutting edge thickness(<2 mm)had no significant effects on soil properties of seedbed.This study could provide a reference for optimal design of the tine furrow opener to create more suitable seedbed environment,and promote the application of the light no-till planters.

Design and experimental validation of sliding knife notch-type disc opener for a no-till combine harvester cum seed drill

One major constraint in developing a combine harvester cum seed drill(CHCSD)is the limited space available for the attachment of no-till furrow openers.Investigating the straw stubble cutting and furrow opening performance of small-sized disc furrow openers is critically important for the development and the optimization of the no-till seeding assemblies.A set of down-scaled sliding knife notch-type disc opener(SKO),modified notch-type disc opener(MNO)and smooth-type disc opener(SDO),with upper size limit of 160 mm,were designed and fabricated for field testing.Experimental results show that for small-sized disc furrow openers of the same type,a larger disc diameter yields a greater furrow depth and width.For small-sized disc furrow openers with an identical diameter,SKOs yield a greater furrow depth and width than MNOs,with SDOs yielding the lowest values.The measured furrow depth and width for an SKO with diameter of 160 mm are 3.52 cm and 3.56 cm,respectively,meeting the no-tillage furrowing requirements for a CHCSD.The highest stubble cover rate of 62.5%is obtained for the SKO with diameter of 160 mm.Therefore,this opener has greater ability to remove stubble from the furrow and seeding band than the other designs.Finally,experimental results of the stubble cutting rates confirm that,for irregularly placed straw and residue,the stubble cutting rate of the SKO with diameter of 160 mm is the highest at 61.7%.

Discrete element method simulation of disc type furrow openers in paddy soil

For granular materials,discrete element modeling is one of the best computer tools to simulate their behavior and interactions.A field experiment was carried out to evaluate the performance of disc furrow openers in paddy soil.Discrete element simulation was done to develop a 3D DEM model for notched,toothed and double disc furrow openers using EDEM software.Hertz Mindlin contact model with bonding was applied for simulation to fulfill the obligations of the soil moisture and bonding between the cohesive particles.Simulated and field experimental data were compared to determine the applicability in the different working conditions.The results of the simulation validated the applicability of the Hertz-Mindlin contact model with bonding to simulate the no till paddy soil using an extremely narrow tillage tool.The calibrated value of normal and shear stiffness was 5×10^(7)N/m,and the calibrated value of bond normal and shear strength was 3×10^(7)Pa.The relative error(-1.7%to 20.6%)for the double disc furrow opener was lower as compared with that notch typed(29.2%to 44.4%)and toothed type(31.5%to 45.9%)furrow openers.

Design and experiment evaluation of furrow compaction device with opener for maize

The double-disc opener of maize precision seeder is an important component which affects sowing quality.After the double-disc opening operation,there will be many unfavorable phenomena such as a W-shaped bottom with pointed ridge,returning soil to furrow,loose and rough furrow sidewall,and large soil blocks in the furrow bottom.These phenomena often cause the problems of poor sowing depth consistency and seed spacing uniformity.In order to solve the above problems,the furrow compaction device with opener was designed to compact and reshape the original seed furrow,eventually forming a smooth and flat V-shaped seed furrow.Through theoretical calculations and kinematic analysis,the main structural parameters of the device were limited to a small range:the spring stiffness coefficient k=0.96-4.19 N/mm and the angle of the furrow compaction wheelφ=30°-60°.In the soil-bin experiment,the rotary combination design was adopted to study the effects of the parameters of the furrow compaction device with opener on the seeds location variation.The regression model of two factors with respect to each indicator was established in the Design-Expert software,revealing the effects of two factors on the indicators.Finally,the optimal structural parameters obtained were:the spring stiffness coefficient k=4.0 N/mm,and the angle of furrow compaction wheelφ=42.4°.The field test was carried out to verify the effect of the furrow compaction device with opener on the performance of precision seeder.The results showed that the average values of the sowing depth variable coefficient,the lateral deviation and the seed spacing variable coefficient respectively were 5.77%,5.1 mm and 9.54%in the treatment of the furrow compaction device with opener.All indicators were superior to the traditional double-disc opener.This research can provide references for the design of furrow opening device and maize precision seeder.

Furrow design for improving crop establishment of two-wheel tractor operated strip tillage planters in loam and clay loam soils

Conservation agriculture(CA)based production systems may help in achieving more sustainable intensification of cropping systems that use less labour and energy and have higher profit margins,in addition to soil conservation and environmental impact mitigation advantages.But these objectives can only be achieved when the right mechanization options,including appropriate crop establishment equipment,are in place to assist in timely field operations.An urgent need exists,therefore,to fine tune and re-adjust the existing two-wheel tractor(2WT)operated seed drills,with specific reference to the design of blade and furrow openers,while at the same time considering performance in different soil types and environments.To this end,experiments were conducted during 2013-2014 and 2014-2015 at two BARI Regional Agricultural Research Stations in Jamalpur and Barisal,Bangladesh,on a loam and clay loam soil,respectively,to evaluate five types of furrow opener for strip tillage.Shoe and modified shoe-type furrow openers were tested and compared with three inverted-T furrow openers with rake angles of 75°,65°and 55°.The newly designed inverted-T furrow openers were narrower than the shoe-type openers;they also had a longer,hollow shanks and provided better options for adjustment to achieve the desired seeding depth and line spacing.Compared to shoe-type openers,better seeding depth,uniformity and higher degree of seed coverage were recorded with use of the inverted-T furrow opener with a 65°rake angle.This resulted in better seed coverage in the furrow,a higher emergence rate index,and the highest emergence percentage of maize and mung bean.Our research findings can be generalized to smallholder production systems on loam and clay loam soils where farmers utilize 2WT operated seed drills for crop establishment in both traditional and conservation agriculture-based planting systems.