INMATEH Agricultural Engineering is an open access international journal that publishes reviewed original research papers of both experimental and theoretical nature in the following areas: Technologies and technical equipment for agriculture and food industry, Environmental-friendly agriculture, Renewable energies, Technical equipment testing, Environment, Transport in agriculture, others

INMATEH Agricultural Engineering is an open access international journal that publishes reviewed original research papers of both experimental and theoretical nature in the following areas: Technologies and technical equipment for agriculture and food industry, Environmental-friendly agriculture, Renewable energies, Technical equipment testing, Environment, Transport in agriculture, others

In rape combine harvester, side cutter must be equipped to cut off tangled rapeseed twigs. Inappropriate cutting speed would increase the repeated cutting and missing cutting of side cutter, which lead to serious header loss. In allusion to the problems mentioned above, bidirectional electric drive side cutter and a cutting speed follow-up adjusting system were proposed. The kinematic law of side cutter blades was analyzed. The trajectory, velocity, and acceleration of the two blades were the same, but the phase difference is π. Numerical simulation of cutting areas at different cutting speed ratios was carried out and the best cutting speed ratio was determined to be 1.1. Cutting speed follow-up adjusting system was designed based on matching relationship between combine harvester forward speed and side cutter cutting speed. Cutting speed follow-up adjusting system was designed with proportional–integral–derivative (PID) algorithm. The control parameters were determined to be K_p = 1.3, K_i = 4.3, K_d = 0.007. Simulation showed that the maximum overshoot of the system was 4.3%, steady-state error was 0.24%, and the rise time was 0.036 s. The cutting speed follow-up adjusting system was applied to the 4LZ-6T-type rape combine harvester. Experimental results showed that the side cutter cutting speed error was within 1.5%. When forward speed changed, the cutting speed response delay time was 1.5 s. The rape combine harvester header average loss was 2.96% and side cutter average loss was 0.81%. Compared to the fixed speed cutting, header loss was reduced by 14.05% and side cutter loss was reduced by 34.76%. The research can reduce the loss of rapeseed combine harvester and provide theoretical basis for the design of rapeseed combine harvester.

A novel pneumatic recovery method was proposed to curb the problem of high losses caused by side-cutting in a rapeseed combine harvester header. The influence of recovery method and material status changes on the recovery effect was studied via the CFD-DEM (computational fluid dynamic- discrete element method) coupling simulation. The effect of airflow action on the recovery effect was compared and analyzed, and the composite pneumatic recovery method was determined. In addition, the influence of material status changes and material feeding rate on the recovery effect was explored, and the critical condition of material blockage in the recovery device was configured. As such, the relationship model between air velocity and recovery rate was constructed and the air distribution ratio of the flow field in the device under this condition was optimized, had verified the rationality of this pneumatic recovery method was verified by a series of field tests. The average rapeseed recovery rate of 92.95% was achieved with the application of the recovery device, and the total loss rate of the header reduced by 52.26%, which is of great significance in reducing the total loss rate of the combine harvesters and improving the operation performance of machinery. The research results can provide a reference for the design of the header structure of a rape combine harvester. Keywords: rapeseed, combine harvester, side-cutting loss, coupled simulation, pneumatic recovery DOI: 10.25165/j.ijabe.20221502.6267 Citation: Jiang T, Zhang M, Guan Z H, Mu S L, Wu C Y, Wang G, et al. Simulation and analysis of the pneumatic recovery for side-cutting loss of combine harvesters with CFD-DEM coupling approach. Int J Agric & Biol Eng, 2022; 15(2): 117–126.

To address the lack of available information on the soil physical conditions suitable for rapeseed blanket-shaped seedling transplanting, as well as the lack of protocols for the optimisation of soil tillage components in the utilisation of an integrated rapeseed blanket seedling combined transplanter, the physical parameters of different soil conditions and their impact on the growth of rapeseed after transplanting were investigated in this study. The aim was to determine the suitable soil physical parameters for rapeseed blanket-shaped seedling transplanting. First, the changes in soil firmness, soil bulk density, and soil moisture content during the installation of the rapeseed blanket seedling combined transplanter were tested and analysed, providing preliminary data for subsequent research. Using the variables of soil firmness and soil moisture content in the micro-environment around the roots and stems (30–50 mm) after rapeseed seedling transplantation and indicators such as the survival rate, root diameter, seedling height, and dry weight, an experiment on the growth of rapeseed blanket-shaped seedlings was conducted based on the furrow cutting transplanting principle. The results indicated that during the initial stage of rapeseed transplanting, the soil moisture content significantly influenced the vitality of the rapeseed plants. Under a high soil moisture content, the typically lengthy seedling period was shortened, and the effect on vitality was good, with minimal influence from the soil firmness. After seedling establishment, the rapeseed growth was significantly affected by the soil firmness. When the soil moisture content was less than 20%, increasing the soil firmness to 500 kPa was beneficial for moisture retention and rapeseed seedling growth. At a soil moisture content ranging from 20 to 25%, a soil firmness of 400 kPa was most suitable for both rapeseed vitality and late-stage growth. When the soil moisture content exceeded 25%, reducing the soil firmness to 300 kPa was beneficial for rapeseed growth, as an excessively high moisture content may lead to soil compaction, affecting seedling development. This study provides a theoretical basis for optimizing the design of soil tillage components in the application of an integrated rapeseed blanket seedling combined transplanter and for the high-yield management of rapeseed after transplanting.