INMATEH - Agricultural Engineering

6

Authors: Pustiulha S., Khomych A., Eng.Tsiz' I., Kirchuk R.

This paper presents an approach, the mathematical algorithms and software implementation of processes of discrete geometric modelling of open storage of bulk materials, such as surfaces of the equal slope, taking into account the geometrical and technological requirements for newly created objects and the physical and mechanical properties of bulk materials forming them. This approach and developed algorithms will not only make possible to technologically project the construction of open storage of bulk materials in time and provide a variety of geometrical requirements to objects, but also to make recommendations for the selection and organization of transporting machines work which are necessary for.

8

Authors: Li S.T., Yang L., Niu P., Zhang Y.H., Xie S.Y., Chen X.B., Yang M.J.

The shapes and parameters of the edge curve of a rotary blade have important influence on the slip cutting performance, soil cutting resistance and soil throwing performance of the rotavators of a handheld tiller. In this study, taking the handheld tiller’s rotary blade as a case study, the mathematical model of the edge curve of the rotary blade was built, and the CAD system of the rotary blade was obtained by means of the secondary development of AutoCAD based on Visual BASIC. Three rotary blades with different diameters and different edge curves were designed through the CAD system, the relative error of system output and calculated values (Excel) of parameters were studied, and the variation of grass removing angle of edge curve, scoop angle and tilling width were analyzed as well. The results showed that: the relative error of the system output and calculated values are at the level of 0.5%; the grass removing angle and scoop angle of edge curve edge are in the preferred value range; with cornerite increase, the grass removing angle and scoop angle linearly increase at large; on conditions of other parameters being constant, the tilling width decreases with increase of alpha angle.

8

Authors: Hu Jun, Song Yujie, Li Hailiang, Fu Qiang, Khokan Kumer Sarker

Seedling picking is important in corn transplantation and can directly influence the efficiency of transplanters. To avoid high injury rate caused by the seedling picking system to separate seedlings and the pot, a pot separator that can cooperate with tube transplanters was designed. First, design requirements of the pot separator were proposed according to corn transplantation demands and the characteristics of the paper pot. Second, based on the transplantation technology of paper potted cultivation, 35-day potted corn seedlings were chosen as test materials. Finally, the cutting characteristics of the paper pot were experimentally studied using a home-made cutting device and a microcomputer control electronic universal testing machine. Results showed that soil with 60%–67% soil moisture content is more suitable for potted corn seedlings. Single paper pot cutting in the shearing mode had the highest integrity and the damage rate was lower than 5%. The conditions to obtain the minimum cutting force of the paper pot were: 63%–67% soil moisture content, 500 mm/min cutting speed, and 30° cutting angle. The cutting force decreased with the increase of soil moisture content, and the maximum cutting force decreased with the increase of cutting speed. Research results provide reference for future optimization of the pot separator and are significant for promoting the development of fully automated corn transplanters.

8

Authors: Farhadi R., Farrokhi Teimourlou R., Abbasalizadeh M.

Reusing water drainage can effectively reduce water consumption in greenhouses. However, disinfection is unavoidable. A proper solar disinfection system needs uniform temperature distribution. Four different adiabatic tanks (prism, changed prism, cube and half-cylinder) were compared to achieve temperature distribution using a 3D computational fluid dynamics simulation. The tanks were equipped with solar heat pipes and their heat flux was assumed constant. A 30 minutes transient simulation was performed. The results showed that the cube tank had the most temperature uniformity, then the prism but with lower mean temperature. The changed prism and half-cylinder had almost similar effects and lower uniformity.

8

Authors: Hevko R.B., Rozum R.I., Klendii O.M.

Having analyzed the designs and the quality indices of process performance for loading loose materials by screw conveyors, new ways and engineering solutions for loading materials into an input flow pipe-line have been suggested. Load analysis has been conducted and analytic dependences of the operation process of cam and link-leverage slewing mechanisms of loading pipe activator have been deduced. Movement patterns of a flow pipe-line in the process of loading pipe operation have been investigated. Experimental studies have been conducted and rational operational parameters and modes for the designed pipes have been determined.

8

Authors: Kaya M. N., Köse F.

Wind energy is being used to generate electricity in many countries all over the world and still the contribution of wind energy to electricity supply increases every day. Researchers work on innovative solutions to increase the efficiency and decrease the cost of wind turbine components, especially those of blades. Various blade designs for different operation conditions are presented in the literature and sweep-twist blades are new type of blades introduced recently. This paper focuses on the numerical investigation of a sweep-twist wind turbine blade using ANSYS-Fluent. NREL Phase VI wind turbine blade is used as the baseline blade and the sweep-twist blade is designed by adding an offset that is 5% of the blade span to the tip. Power output and thrust forces are calculated using the simulation results for both original and sweep blades. In addition, results are compared to the experimental data of original NREL Phase VI blade.

10

Authors: Wang Xuelei, Huang Jie, Zhao Dongjie, Guo Honghong, Li Chuanjun, Zhang Bin

To eliminate the serious threat of weeds to farmland crops, this study proposes a laser weeding robot based on a novel 3UPS-RPU parallel mechanism (PM). The robot uses laser thermal effects to eliminate weeds in crop rows. The novel 3UPS-RPU PM is composed of three UPS-type active legs and one RPU-type active leg. Approaches for solving the inverse kinematics, inverse/forward velocities, inverse/forward accelerations, active forces, and constrained forces of this PM are derived and unified for other PMs with linear active legs. The kinematic curves demonstrate that the input of active legs 1 and 3 are consistent, while the moving platform moves according to a line-type translational movement which is the unique characteristic of the proposed PM. The active legs move according to a non-linear motion law, while the moving platform of the PM moves according to a line-type patterns, which is a common characteristic. The kinematic curves show that this PM has steady movement with no sudden changes or breakpoints which satisfies the stability requirements for the laser in the robot. Theoretical formulas and results provide a basis for the optimization of the structure design, control, dynamic performance analysis, manufacturing, and applications of the 3UPS-RPU PM.

10

Authors: Gao B., Guo M.B., Yang L., Wu D.K., Yang M.J.

Moisture content loss of rapeseed (Brassica napus L.) and drying rate change with time during thin layer hot-air drying were obtained through experiments. By means of volume weighed average, the moisture content loss of rapeseed and airflow distribution in the drying box were simulated and analyzed in FLUENT using methodology of CFD. For heat and mass transfer modelling of the rapeseed drying, a code incorporating the effects of heat and moisture transfer was compiled by means of UDFs (User-Defined Functions), and SIMPLE (Semi-Implicit Method for Pressure-Linked Equations) scheme was adopted to solve the constitutive equations governing the rapeseed drying. Numerical findings were compared with the experimental data, and they had good agreement with experiments: mean relative errors of moisture content, air temperature and air velocity of modelling are 7.48%, 1.07% and 7.72 %, respectively.