Measurement and CFD-DEM Simulation of Suspension Velocity of Peanut and Clay-Heavy Soil at Harvest Time

Abstract

The suspension velocity is the core of the cleaning and sorting mechanisms that utilize a combination of a fan and vibrating sieve. To investigate this, various experimental subjects, such as peanuts with different kernels and clay-heavy clods in different states, were used. The experiment involved simulating the suspension velocity of materials through numerical calculations using fluid dynamics and particle discrete element coupling. The Eularian model was employed to study the coupled gas-solid two-phase flow. The experiment measured the suspension velocities of single and double kernel peanuts, which were found to be 8.34~9.40 m/s and 8.13~9.51 m/s, respectively. Under 20.4% water content and lumpy conditions, the suspension velocities of smaller clods, side by side clods, and larger clods were 12.61~14.30 m/s, 14.16~15.76 m/s and 16.44~18.72 m/s, respectively; under 20.4% water content and smaller clods, the suspension velocities of lumpy and strip of clods were 12.61~14.30 m/s, 11.90~14.13 m/s, respectively; under lumpy and smaller clods, the suspension velocity at 17.6%, 20.4%, and 23.9% water content ranged from 12.38 to 14.20 m/s, 12.61 to 14.30 m/s, and 12.62 to 14.49 m/s, respectively. The simulations showed that the suspension velocity for different types of peanuts, clod sizes, shapes, and water contents was less different from the actual experiments. Specifically, the relative errors in suspension velocity for single-kernel peanuts, double-kernel peanuts, smaller clods, side-by-side clods, larger clods, lumpy clods, strips of clods, and clods with 17.3%, 20.4%, and 23.9% water content were 1.2%, 4.1%, 0.4%, 2.0%, 4.4%, 0.4%, 5.1%, 5.4%, 0.4%, and 1.9%, respectively, compared to actual experiment measurements. The results indicate a significant difference in the suspension velocity between peanuts and clay-heavy clods, which can be distinguished from each other based on this difference. Furthermore, the simulation results have been found to be consistent with the experimental results, thus verifying the feasibility of measuring the material suspension velocity using CFD-DEM gas-solid coupling.

Precision Operation Technology and Intelligent Equipment in Farmland

“…Peanut harvesting machinery is typically based on the soil, and the fruit density is different [70,71], so the choice of an appropriate fan speed and vibrating screen to complete the fruit cleaning is important; however, current studies seldom consider the adhesion characteristics between the soil peds, which leads to a poor clearing effect. The authors of [72] coupled discrete element and fluid simulation modules, conducted experimental research on different soil volumes and soil moisture contents, and optimized the appropriate suspension speed to improve the cleaning effect of peanut harvesting machinery.…”

Design and Parameter Optimization of a Negative-Pressure Peanut Fruit-Soil Separating Device

“…As a result, the efficiency of peanut harvesting is low, and there are significant issues with impurity and loss rates. The development of combine harvesting machinery for peanuts grown in clay-heavy soils is an urgent matter [2,3]. The separation and cleaning process plays a crucial role in the peanut harvesting process as it directly impacts the impurity rate, loss rate, and other indicators used to evaluate the quality of peanut harvesting machinery.…”

“…Ashish S. Raghtate et al [9] designed and manufactured a new medium capacity peanut shelling machine for the lack of peanut shelling machines in India and evaluated the machine performance in terms of productivity, shelling efficiency, material efficiency and mechanical damage. Mingyang Qin et al [3] measured the suspension velocity of peanut pods and clay-heavy soil of different masses, shapes and moisture contents by means of one-way test and CFD-DEM coupling. The researchers obtained the values of the suspension velocity of each material and its separation characteristics, which verified the feasibility of the idea of separating the fruits and soil through the difference of suspension velocity and provided the basis of this study.…”