scholarly journals EXPERIMENT AND PARAMETERS OPTIMIZATION OF SEED DISTRIBUTOR OF MECHANICAL WHEAT SHOOTING SEED-METERING DEVICE

2021 ◽  
pp. 29-40
Author(s):  
Yingbo Wang ◽  
Hongwen Li ◽  
Qingjie Wang ◽  
Jin He ◽  
Caiyun Lu ◽  
...  
Keyword(s):  
High Speed ◽  
Influence Factors ◽  
Parameters Optimization ◽  
Wheat Seed ◽  
Seed Damage ◽  
Movement Characteristics ◽  
Motion Process ◽  
Inner Diameter ◽  
Verification Test ◽  
Seed Metering Device

In order to solve problems of lower seed-filling stability and wheat seed damage of mechanical shooting seed-metering device, the filling structure of the shooting device was optimized. The effects of seed movement were obtained through analysing the kinematics and dynamics of wheat seed through seed distributor. The influence factors were the inner diameter of seed distributor, the rotational speed of seed distributor and the inclination angle of distributor window. The discrete element software (DEM) was used to simulate the motion process to explore the different factors on the wheat seeds’ movement characteristics in the shooting device. The coefficient of variation of shooting uniformity and shooting speed of wheat seed were selected as test indicators. A verification experiment was conducted, and a high-speed camera was taken to obtain wheat seed’s movement and shooting speed. The verification test showed that the constant uniform variation coefficient of seed amount and average shooting depth was 8.6% and 32 mm, respectively.

Structural Design and Parameters Optimization of Rice Seed-Metering Device

2013 ◽  
Vol 397-400 ◽  
pp. 957-965
Author(s):  
Jing Ma ◽  
Xiao Long Lei ◽  
Rong Chao Ma
Keyword(s):  
Influence Factors ◽  
Travel Speed ◽  
Parameters Optimization ◽  
Rice Seed ◽  
Delivery Tube ◽  
Experimental Conditions ◽  
Design Expert ◽  
Working Parameters ◽  
Seed Metering Device

In order to improve the seeding quality of paddy planter, some parts of rice seed-metering, such as sufficient regulator and delivery tube, were optimally designed, and field experiment was completed to optimize the structural and working parameters. Central composite design was employed to as design the experimental plan by means of the Design-Expert software (Version 7.0). The parameters of travel speed (A), sufficient regulator’s angle (B) and length of delivery tube (C) were selected as influence factors, and seeding quality rate(y1), damage ratio of seeding(y2) and ratio of seeding holes(y3) were chosen as objective indexes. Regression models were established and analyzed based on Design-Expert and SAS software. The experiment results indicated that sufficient regulator improved quality of seeding and ratio of seeding holes especially with a few rice seeds in seed room. Under experimental conditions, the importance of each variable on y1, y2 and y3 was A>C>B, C>B>A and C>B>A and effects of the interaction of A and C on y1, the interaction of B and C on y2 and the interaction of A and C on y3 were significant by response surface analysis. By multiple objective programming, the optimal parameters were obtained as follow: travel speed of 2.8km/h, angle of sufficient regulator of 72°and delivery tube’s length of 0.25m. This study has important significant to well improvement seeding quality of rice direct-seeding.

Research on High-Speed Cutting of Cr12MoV Hardened Steel - A Review

2020 ◽  
Vol 15 ◽  
Author(s):  
Fei Sun ◽  
Guohe Li ◽  
Qi Zhang ◽  
Meng Liu
Keyword(s):  
High Speed ◽  
Cutting Temperature ◽  
High Hardness ◽  
High Strength ◽  
Hardened Steel ◽  
Parameters Optimization ◽  
Future Research ◽  
High Speed Machining ◽  
Machined Surface ◽  
Stamping Die

: Cr12MoV hardened steel is widely used in the manufacturing of stamping die because of its high strength, high hardness, and good wear resistance. As a kind of mainstream cutting technology, high-speed machining has been applied in the machining of Cr12MoV hardened steel. Based on the review of a large number of literature, the development of high-speed machining of Cr12MoV hardened steel was summarized, including the research status of the saw-tooth chip, cutting force, cutting temperature, tool wear, machined surface quality, and parameters optimization. The problems that exist in the current research were discussed and the directions of future research were pointed out. It can promote the development of high-speed machining of Cr12MoV hardened steel.

Temperature Rise Prediction of Oil-Air Lubricated Angular Contact Ball Bearings Using Artificial Neural Network

2019 ◽  
Vol 12 (3) ◽  
pp. 248-261
Author(s):  
Baomin Wang ◽  
Xiao Chang
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Temperature Rise ◽  
High Speed ◽  
Ball Bearing ◽  
Influence Factors ◽  
Ball Bearings ◽  
Ann Model ◽  
Angular Contact Ball Bearing ◽  
Artificial Neural

Background: Angular contact ball bearing is an important component of many high-speed rotating mechanical systems. Oil-air lubrication makes it possible for angular contact ball bearing to operate at high speed. So the lubrication state of angular contact ball bearing directly affects the performance of the mechanical systems. However, as bearing rotation speed increases, the temperature rise is still the dominant limiting factor for improving the performance and service life of angular contact ball bearings. Therefore, it is very necessary to predict the temperature rise of angular contact ball bearings lubricated with oil-air. Objective: The purpose of this study is to provide an overview of temperature calculation of bearing from many studies and patents, and propose a new prediction method for temperature rise of angular contact ball bearing. Methods: Based on the artificial neural network and genetic algorithm, a new prediction methodology for bearings temperature rise was proposed which capitalizes on the notion that the temperature rise of oil-air lubricated angular contact ball bearing is generally coupling. The influence factors of temperature rise in high-speed angular contact ball bearings were analyzed through grey relational analysis, and the key influence factors are determined. Combined with Genetic Algorithm (GA), the Artificial Neural Network (ANN) model based on these key influence factors was built up, two groups of experimental data were used to train and validate the ANN model. Results: Compared with the ANN model, the ANN-GA model has shorter training time, higher accuracy and better stability, the output of ANN-GA model shows a good agreement with the experimental data, above 92% of bearing temperature rise under varying conditions can be predicted using the ANNGA model. Conclusion: A new method was proposed to predict the temperature rise of oil-air lubricated angular contact ball bearings based on the artificial neural network and genetic algorithm. The results show that the prediction model has good accuracy, stability and robustness.

Experimental Characterization of a Modified Airlift Pump

2014 ◽  
Author(s):  
Afshin Goharzadeh ◽  
Keegan Fernandes
Keyword(s):  
Water Flow ◽  
Flow Rate ◽  
High Speed ◽  
Water Flow Rate ◽  
High Speed Photography ◽  
Two Phase ◽  
Inner Diameter ◽  
Airlift Pump ◽  
Flow Map ◽  
Churn Flow

This paper presents an experimental investigation on a modified airlift pump. Experiments were undertaken as a function of air-water flow rate for two submergence ratios (ε=0.58 and 0.74), and two different riser geometries (i) straight pipe with a constant inner diameter of 19 mm and (ii) enlarged pipe with a sudden expanded diameter of 19 to 32 mm. These transparent vertical pipes, of 1 m length, were submerged in a transparent rectangular tank (0.45×0.45×1.1 m3). The compressed air was injected into the vertical pipe to lift the water from the reservoir. The flow map regime is established for both configurations and compared with previous studies. The two phase air-water flow structure at the expansion region is experimentally characterized. Pipeline geometry is found to have a significant influence on the output water flow rate. Using high speed photography and electrical conductivity probes, new flow regimes, such as “slug to churn” and “annular to churn” flow, are observed and their influence on the output water flow rate and efficiency are discussed. These experimental results provide fundamental insights into the physics of modified airlift pump.

Effects of vessel baffling on the drawdown of floating solids

2009 ◽  
Vol 63 (2) ◽  
Author(s):  
Joanna Karcz ◽  
Beata Mackiewicz
Keyword(s):  
Experimental Data ◽  
Power Consumption ◽  
Strain Gauge ◽  
High Speed ◽  
Vessel Diameter ◽  
Rushton Turbine ◽  
Agitated Vessel ◽  
Dimensionless Equation ◽  
Inner Diameter ◽  
Floating Particles

AbstractThe effects of baffling of an agitated vessel on the production of floating particles suspension are presented in this paper. Critical agitator speed, needed for particles dispersion in a liquid agitated in a vessel of the inner diameter of 0.295 m, was determined. The just drawdown agitator speeds were defined analogously to the Zwietering criterion. Specific agitation energy was calculated from the power consumption experimental data obtained by means of the strain gauge method. The experiments were carried out for twelve configurations of the baffles differing in number, length and their arrangement in the vessels. The following high-speed impellers were used: up- and downpumping six blade pitched blade turbines, Rushton turbine, and propeller. The impeller was located in the vessel in the height equal to two-thirds or one-third of the vessel diameter from the bottom of the vessel. The results were described in the form of a dimensionless equation.

Study on Dynamic Accuracy of CNC in Aviation Part

2011 ◽  
Vol 314-316 ◽  
pp. 1717-1720
Author(s):  
Li Du ◽  
Wei Wang ◽  
Zhi Yong Song ◽  
Jie Xiong Ding
Keyword(s):  
High Speed ◽  
Influence Factors ◽  
Maximum Error ◽  
Error Sources ◽  
Dynamic Accuracy ◽  
Cutting Test ◽  
Manufacture Process ◽  
Shape Precision ◽  
Dynamic Errors ◽  
And Control

Thin-walled parts are widely used in aerospace engineering. For their complexity under loading and the higher shape precision, it’s difficult for their manufacturing on high speed machine. In order to understand manufacture process, characteristic of aviation part in high speed machining is investigated. Error sources on parts are classified and the maximum error, dynamic errors are studied on its main influence factors, such as cutting force and vibration. Finally, useful method on cutting test part is proposed, which can observe and control dynamic accuracy of aviation part and ensure effective manufacture.

Study on Oil-Ash Corrosion and Coal-Ash Corrosion Occurred in the Flue-Gas Side of Fossil Power Plant

2011 ◽  
Vol 418-420 ◽  
pp. 918-921
Author(s):  
Yong Yan Zhou ◽  
Yu Zhou ◽  
Guo Hua Lu ◽  
Tian Sheng Chen
Keyword(s):  
Flue Gas ◽  
High Speed ◽  
Fossil Fuels ◽  
Influence Factors ◽  
Heating Surface ◽  
Coal Ash ◽  
Chemical Corrosion ◽  
Boiler Tubes ◽  
Prevention Methods ◽  
Fossil Power Plant

A large number of high-speed soot particles would be produced after fossil fuels' (oil or coal) combustion in the boiler. These high-speed particles not only directly attack the heating surface of boiler tubes (damaging the tubes mechanically), but also condensate on the wall, causing even more serious chemical corrosion. The discussion has deeply studied the occurrence sites, reaction mechanism, influence factors as well as identification and prevention methods of oil-ash corrosion, coal-ash corrosion, so it would have a positive guiding significance for reducing (or preventing) the flue-gas side corrosion.

scholarly journals Three-Dimensional (3-D) Immersed-Boundary (IB) Based Tornado Model for Computational Analysis of Disastrous Wind Load on Buildings

2021 ◽  
Author(s):  
Xixiong Guo ◽  
Jun Cao
Keyword(s):  
Wind Field ◽  
High Speed ◽  
Outer Boundary ◽  
Three Dimensional ◽  
Influence Factors ◽  
Research Direction ◽  
Wind Loading ◽  
Immersed Boundary ◽  
Design Strategies ◽  
Straight Line

This study is aimed at developing a novel computational framework that can essentially simulate a tornadic wind field and investigate the wind loadings on ground constructions. It is well known that tornado is a highly turbulent airflow that simultaneously translates, rotates and updrafts with a high speed. Tornadoes induce a significantly elevated level of wind forces if compared to a straight-line wind. A suitably designed building for a straight-line wind would fail to survive when exposed to a tornadic-like wind of the same wind speed. It is necessary to design buildings that are more resistant to tornadoes. Since the study of tornado dynamics relying on field observations and laboratory experiments is usually expensive, restrictive, and time-consuming, computer simulation mainly via the large eddy simulation (LES) method has become a more attractive research direction in shedding light on the intricate characteristics of a tornadic wind field. For numerical simulation of a tornado-building interaction scenario, it looks quite challenging to seek a set of physically-rational and meanwhile computationally-practical boundary conditions to accompany traditional CFD approaches; however, little literature can be found, as of today, in three-dimensional (3D) computational tornado dynamics study. Inspired by the development of the immersed boundary (IB) method, this study employed a re-tailored Rankine-combined vortex model (RCVM) that applies the “relative motion” principle to the translational component of tornado, such that the building is viewed as “virtually” translating towards a “pinned” rotational flow that remains time-invariant at the far field region. This revision renders a steady-state kinematic condition applicable to the outer boundary of a large tornado simulation domain, successfully circumventing the boundary condition updating process that the original RCVM would have to suffer, and tremendously accelerating the computation. Wind loading and its influence factors are comprehensively investigated and analyzed both on a single building and on a multiple-building configuration. The relation between the wind loadings and the height and shape of the building is also examined in detail. Knowledge of these loadings may lead to design strategies that can enable ground construction to be more resistant to tornadoes, reducing the losses caused by this type of disastrous weather.

Kriging-Based Reliability Analysis and Variance-Based Sensitivity Analysis for an Idler Shaft

2015 ◽  
Author(s):  
Weimin Cui ◽  
Wei Guo ◽  
Zhongchao Sun ◽  
Tianxiang Yu
Keyword(s):  
Sensitivity Analysis ◽  
Influence Factors ◽  
Random Variables ◽  
Kriging Model ◽  
Element Analysis ◽  
Performance Function ◽  
The Finite Element Analysis ◽  
Inner Diameter ◽  
Sensitivity Method ◽  
The Relationship

In order to analyze the reason of failure and improve the reliability of the idler shaft, this paper studies the reliability and sensitivity for the idler shaft based on Kriging model and Variance Methods respectively. The finite element analysis (FEA) of idler shaft is studied in ABAQUS firstly. Then, combining the performance function and various random variables, the Kriging model of idler shaft is established and verified. Based on Kriging model which has been established, the relationship between random variables and the response value is studied, and the function reliability is calculated which explains why the failure of the idler shaft occurred frequently in service. Finally, the variance-based sensitivity method is used for sensitivity analysis of influence factors, the result shows that the reliability of idler shaft is sensitive to the inner diameter of body A and inner diameter of body B, which could contribute for the analysis and further improvement of idler shaft.

Sign in / Sign up

Export Citation Format

Share Document