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.

The chassis of rice transplanter tends to vibrate severely in the severe working environment, causing a severe effect on the operational performance and driving comfort. In order to avoid this situation, this paper constructs a vibration evaluation system of the rice transplanter and carries out experimental analysis. According to the optimal acceleration sensor placement scheme, a test platform system was designed. Taking the high-speed transplanter chassis as the research object, this study carried out the experiments modal analysis and optimization on the chassis. The three-dimensional model of the transplanting machine chassis established by SolidWorks was imported into ANSYS Workbench for finite element modal simulation analysis. Comparing the two modal analyses, it is found that the results data of the two analysis methods were very close. After optimization, the length x1, the section width x2 and the thickness of the hollow beam x3 of the main load-bearing beam of the frame were as follows : x1=1641.5 mm, x2 =26.7 mm, x3=5 mm, respectively. The maximum overshoot of the low-level system was reduced by 28.57%. It has been verified that the vibration of the whole machine has been effectively reduced. Keywords: chassis, high-speed rice transplanter, vibration evaluation, modal analysis DOI: 10.25165/j.ijabe.20221504.7244 Citation: Jin X, Cheng Q, Tang Q, Wu J, Jiang L, Wu C Y, et al. Research on vibration reduction test and frame modal analysis of rice transplanter based on vibration evaluation. Int J Agric & Biol Eng, 2022; 15(4): 116–122.

Transmission belt is one of the most likely to fail parts of combine harvester, which affecting the machine reliability seriously. Dynamic strength occurs along with vibration during the operation and must be taken into account when calculating reliability, especially in harsh working environment like harvesting. However, the existing calculation method of reliability on combine harvester transmission belt didn't take the dynamic strength into account. In this research, a reliability calculation method was proposed based on the dynamic analysis of transmission belt. The nonlinear dynamic equation was built using string and beam model. Through the equation, relationship between belt speed and dynamic stress was deduced. Considering dynamic stress and regarding uncertain parameters as random uncertain parameters, reliability calculation model was built. Finally, an example was presented and the above mentioned dynamic reliability calculation method was simulated to verify the theoretical analysis in this paper and tested by the Monte-Carlo method.