scholarly journals Seeding Performance Simulations and Experiments for a Spoon-Wheel Type Precision Cottonseed-Metering Device Based on EDEM

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Yudao LI ◽  
Shulun XING ◽  
Shasha LI ◽  
Liu LI ◽  
Xiaohui ZHANG ◽  
...  
Keyword(s):  
Tilt Angle ◽  
Coefficient Of Variation ◽  
Working Process ◽  
Passing Rate ◽  
Seeding Effect ◽  
Seed Spacing ◽  
Motion Parameters ◽  
Simulation Results ◽  
Working Performance ◽  
Seed Metering Device

To study the effects of seed metering on seeding performance under different motion parameters, a simulation model for a spoon-wheel type seeder was established. A seed meter was tested by using EDEM (Engineering Discrete Element Method) software to simulate its working process at different speeds and tilt angles. The trajectories of individual cottonseeds in the seed-metering device were obtained, concurrently, the stress trend in the grain group was determined as a function of time. The simulation results suggest that at larger speeds, the metering index of the seed meter gradually decreases, while the index and the missing index gradually increase. As the tilt angle increased, the multiples index and missing index gradually decreased, while the multiples index gradually increased. When the seed meter speed reached 50 r/min and the tilt angle was 15°, the seed meter had a relatively good working performance with a seed spacing acceptance index of 92.59%, a multiples index of 1.85%, and a missing rate index of 5.56%. The seed meter was tested on a bench by using a JPS-12 performance-tester bench. At the aforementioned speed and angle, the coefficient of variation for the cottonseed spacing was 2.1%. The field trial results indicated that the multiples and the missing rates were higher than those for the tester bench but still met a passing rate of more than 90%. The coefficient of variation for the seed spacing was less than 10%, suggesting that the design could be used for field sowing. The resulting seeding uniformity was higher under these conditions, which indicates that the seed meter has a better working performance and the bench has a good seeding effect.

Evaluation of a Steam Jet Refrigerator with the Varying Specific Heat Ratio

2013 ◽  
Vol 385-386 ◽  
pp. 220-224
Author(s):  
Wen Bin Cui ◽  
Feng Min Su ◽  
Hai Jun Li
Keyword(s):  
Specific Heat ◽  
Constant Pressure ◽  
Refrigeration System ◽  
Analysis Model ◽  
Working Process ◽  
Specific Heat Ratio ◽  
Simulation Results ◽  
Working Performance

To predict the working performance of the jet refrigeration system more precisely, including the condensing temperature and coefficients of performance, this paper presents a 1-D analysis model with the varying specific heat ratio. During the evaluation, the working process of the constant pressure ejector is divided into three sections with different specific heat ratios. By comparing the results from Eames experiment, the simulation results indicate that this model is more reasonable, and the error of the simulation is within 20%, which is significantly smaller than the error of Eames model at 40%.

Optimization of the operational parameters of a picking-type pneumatic planter using response surface methodology

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
SK PATEL ◽  
JB BHIMANI ◽  
P GUPTA ◽  
BK YADUVANSHI
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Important Variable ◽  
Vacuum Pressure ◽  
Forward Speed ◽  
Operational Parameters ◽  
Seed Spacing ◽  
Lady’S Finger ◽  
Multiple Regression Technique ◽  
Seed Metering Device

Singulation of seeds has been investigated extensively by researchers all over the world and a large number of precision seeding systems with design variations have been developed for different crops. A picking type metering mechanism was developed at CAET, AAU, Godhra, Gujarat, India. The performance of the picking type seed-metering device of a pneumatic planter was investigated under laboratory conditions to optimize the operating parameters for lady's finger seed. The picking of single seed the three operational parameters i.e. hole diameters for the nozzle: 1.0, 1.5, 2.5 and 3.0 mm; forward speed: 0.37, 0.56, 0.83, 1.11 and 1.30 m/s and vacuum pressure: 19.33, 39.32, 43.98, 58.64 and 68.63 kPa were selected for the study. The metering system of the planter was set to place the seed to seed spacing at 300 mm. The response surface methodology (RSM) technique was used to optimize the operational parameters of a precision planter. For optimizing the forward speed, vacuum pressure and nozzle size for developed machine was evaluated by examining the miss index, multiple index, quality of feed index and precision. The data obtained in the experiments were used to develop functions in polynomial form using multiple regression technique. The optimum value was found to be around 0.96 m/s, 36.25 kPa and 2.0 mm of forward speed, vacuum pressure and the holes diameter of nozzle, respectively. The most important variable that governs planting phenomenon is the combination of hole diameter of nozzle and vacuum pressure accounts 89.18 per cent.

Simulation Analysis of the Working Process of the Corn Seed Metering Device with Combination Inner-Cell

2012 ◽  
Vol 215-216 ◽  
pp. 160-167 ◽  
Author(s):  
Qing Long Li ◽  
Ji Yang Yu ◽  
Qiang Qiang Zhang ◽  
Jian Qun Yu ◽  
Hong Fu
Keyword(s):  
Simulation Analysis ◽  
Three Dimensional ◽  
Bench Test ◽  
Particle Model ◽  
Test Results ◽  
Working Process ◽  
Corn Seed ◽  
3D Cad ◽  
Novel Method ◽  
Seed Metering Device

A three-dimensional discrete element method analytic model of the corn seed metering device with combination inner-cell was established based on its 3D CAD model, and the three-dimensional particle model of corn seeds was built by using the method of combination spherical particle. The working process of the corn seed metering device was simulated and analyzed by self-developed three-dimensional CAE software. It was observed that the simulative results of the seeding performance, clearing angles and dropping angles of the corn seeds well agreed with the bench test results. A novel method for studying and designing of the corn seed metering device was put forward.

scholarly journals Dynamics of the mobile platform with four wheel drive

2019 ◽  
Vol 254 ◽  
pp. 03006
Author(s):  
Anna Jaskot ◽  
Bogdan Posiadała
Keyword(s):  
Theoretical Model ◽  
Mobile Platform ◽  
Kutta Method ◽  
Friction Forces ◽  
Runge Kutta Method ◽  
Wheel Drive ◽  
Motion Parameters ◽  
Simulation Results ◽  
Four Wheel Drive ◽  
Unsteady Conditions

The dynamics problem of motion of the mobile platform with four wheel drive under the unsteady conditions have been formulated and analysed. The mobile platform prototype have been equipped with four independently driven and steered electric drive units.The theoretical model have been formed for the proposed design concept of the platform. The relations between friction forces in longitudinal and transverse directions in reference to the active forces have been considered. The analysis of the motion parameters for different configurations of the wheel positions has been included. The formulated initial problem has been numerically solved by using the Runge-Kutta method of the fourth order. The sample simulation results for different configurations of the platform elements during its motion have been included and the conclusions have been formulated.

Design and Analysis of One Kind of Preliminary Storage Centrifugal Action Mechanism Applied to Submunition Fuze

2013 ◽  
Vol 718-720 ◽  
pp. 1624-1629
Author(s):  
Sheng Gang Xu ◽  
Yan Xuan Wu ◽  
Ning Jun Fan ◽  
Dong Qing Cheng ◽  
Dong Ze Qin
Keyword(s):  
Dynamic Simulation ◽  
Working Environment ◽  
Action Mechanism ◽  
Working Process ◽  
Development Status ◽  
Mechanical Structure ◽  
Simulation Results ◽  
And Function ◽  
Centrifugal Action

According to the requirement of the U.N. for the rate and function of dud, this paper proposes a project to improve mechanical structure of original submunition combing with the development status of submunition in China. With the characteristics of submunition fuzes structure and working environment, one kind of preliminary storage centrifugal action mechanism is designed in the paper. The principle and process of action are also elaborated. The paper makes calculation of reliability and does dynamic simulation by stages according to working process of submunition. Calculation and simulation results demonstrate that preliminary storage centrifugal action mechanism can be reliable and achieves the aim of design.

Design and Test of a Double-Curved Guiding Groove for a High-Speed Precision Seed-Metering Device

2020 ◽  
Vol 63 (5) ◽  
pp. 1349-1360
Author(s):  
Pan Xue ◽  
Yujun Hao ◽  
Wan Jiao ◽  
Jie Ren ◽  
Feifei Yang ◽  
...  
Keyword(s):  
Inclination Angle ◽  
High Speed ◽  
Element Model ◽  
Discrete Element ◽  
Travel Speed ◽  
Curved Surface ◽  
Discrete Element Model ◽  
Release Point ◽  
Seed Spacing ◽  
Seed Metering Device

HighlightsThe instability of the seed release point in a seed-metering device is proved theoretically.A double-curved guiding groove at the seed-release point improves the seed-metering uniformity.A discrete element model was used to examine effects of the design parameters on the metering performance.The critical parameters for the double-curved guiding groove design were determined.Abstract. The instability of the seed release point in a seed-metering device is one of the main causes of the non-uniformity of seed spacing. To improve the seed spacing uniformity, a double-curved guiding groove (DGG) was designed based on the prerelease adaptive principle. The DGG was used at the seed release point of an existing high-speed precision soybean seed-metering device with a double-setting plate. The results showed that the prerelease curved surface of the DGG was capable of guiding seeds to be released at the same seed release point at all times, and the adaptive curved surface of the DGG prevented any changes in seed velocity caused by friction or collisions between seeds and the meter, thereby improving the seed spacing uniformity significantly. A discrete element model was developed and validated with laboratory tests. Through simulations using the model, the primary and secondary factors of the DGG impacting the qualified rate of seed metering (QRM) and the coefficient of variation of the seed spacing uniformity (CVU) were identified and were, in descending order, the spacing of prerelease (SPR), the starting position of prerelease (SPP), the inclination angle of the seed outlet (ASO), and the inclination angle of the receiving cup (ABR). Regression equations of the QRM and CVU with the two main impacting factors were then established. For a planter travel speed of 10 km h-1, the optimal SPR was 10 mm, and the optimal SPP was 40°, where the QRM was 100% and the CVU was 16.61%. When compared to seed metering without the DGG, the CVU was reduced by 2.55%, showing that the DGG significantly improved the uniformity of seed spacing. Keywords: Double-curved guiding groove, Discrete element method, Seed-metering device, Travel speed, Uniformity.

Analysis of the Kinematics of an Eight-Wheeled Mobile Platform

2013 ◽  
Vol 198 ◽  
pp. 67-72
Author(s):  
Marek Stania
Keyword(s):  
Inverse Kinematics ◽  
Object Motion ◽  
Forward Kinematics ◽  
Contact Phenomenon ◽  
Kinematics Model ◽  
Inverse Kinematics Problem ◽  
Transport Vehicle ◽  
Forward And Inverse Kinematics ◽  
Motion Parameters ◽  
Simulation Results

This paper presents the modeling problem connected with the autonomous transport vehicle designed at Hochschule Ravensburg-Weingarten. The forward and inverse kinematics problem of eight-wheeled autonomous transport vehicle have been formulated and solved, additionally examples of simulation results representing the changes of individual motion parameters have been presented. Contact phenomenon between foundation and drive wheel has been taken into account in the kinematics model. Motion trajectory and velocity of the selected point belonging to the platform have been intended while the inverse kinematics problem has been solved. The forward kinematics problem has been worked out in order to verify correctness of the studied kinematics model. The presented simulation results point out compatibility of the worked out kinematics model of investigated object. The worked out models allow carrying out analysis of object motion through simulation investigations on the basis of proposed computational model.

scholarly journals Statistical Tests for the Reciprocal of a Normal Mean with a Known Coefficient of Variation

2015 ◽  
Vol 2015 ◽  
pp. 1-5
Author(s):  
Wararit Panichkitkosolkul
Keyword(s):  
Monte Carlo Simulation ◽  
Coefficient Of Variation ◽  
Statistical Tests ◽  
Taylor Series Expansion ◽  
Type I ◽  
Type I Errors ◽  
Monte Carlo Simulation Study ◽  
Asymptotic Test ◽  
Normal Mean ◽  
Simulation Results

An asymptotic test and an approximate test for the reciprocal of a normal mean with a known coefficient of variation were proposed in this paper. The asymptotic test was based on the expectation and variance of the estimator of the reciprocal of a normal mean. The approximate test used the approximate expectation and variance of the estimator by Taylor series expansion. A Monte Carlo simulation study was conducted to compare the performance of the two statistical tests. Simulation results showed that the two proposed tests performed well in terms of empirical type I errors and power. Nevertheless, the approximate test was easier to compute than the asymptotic test.

Numerical Simulation of Intercepting Efficiency on Airbag Active Protection System

2010 ◽  
Vol 156-157 ◽  
pp. 360-366
Author(s):  
Kun Zhong ◽  
Zhong Hua Du ◽  
Liang Zhou ◽  
Li Li Song
Keyword(s):  
Element Model ◽  
Protection System ◽  
Working Process ◽  
3D Finite Element ◽  
Advantages And Disadvantages ◽  
Active Protection ◽  
New Type ◽  
Simulation Results ◽  
Set Up ◽  
Metal Jet

Based on the advantages and disadvantages of existing active protection system, this paper proposes a new type of airbag active protection system. The components and working process of the system is introduced. Then taking the physical process of airbag active protection system against a rocket projectile as an example, a 3D finite element model (FEM) of airbag and rocket projectile is set up. With the assistance of the software LS-DYNA3D, through performing the simulation when the rocket projectile touched the airbag with an angle 30° from the normal interface, the intercepting efficiency is calculated and analyzed in the simulation. Results show that airbag can deform and rupture the metal jet generated by the rocket projectile, thus greatly reduce its armor penetrating effect. Finally, it shows excellent protective effect of the airbag active protection system.

Simulation Study the Movement of Materials in Loader Shovel Working Process Based on EDEM

2013 ◽  
Vol 655-657 ◽  
pp. 320-325 ◽  
Author(s):  
Peng Peng Huang ◽  
Xi Zhou Xiao
Keyword(s):  
Particle Size ◽  
Simulation Model ◽  
Slip Plane ◽  
Three Dimensional ◽  
Discrete Element ◽  
Working Process ◽  
Loading Process ◽  
Motion Characteristic ◽  
Simulation Results ◽  
Dimensional Simulation

By application of the theory and methods of discrete element, a loader loading process three-dimensional simulation model was established, the simulation model established in EDEM software realized the visualization of loader inserting process. By three different particle size materials inserting process simulation, material motion characteristic could be obtained and the laws of motion of different size material were compared. Simulation results show that regardless of the particle size, compaction zone (dense core) were generated. For small particles, during insertion of the material there was a distinct shear slip plane and for coarse particles, slip plane was not obvious. The simulation results were consistent with the results of previous analysis and verified that the discrete element method and the model in the loading process were effective in the study.

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