scholarly journals Determination of machines working elements speeds optimal correlation when watermelons and cabbages harvesting

2019 ◽  
pp. 89-94
Author(s):  
Aleksey Nikolayevich Tseplyaev ◽  
Maxim Vladimirovitch Ulyanov ◽  
Aleksey Vitalievich Tseplyaev ◽  
Sergey Anatolyevich Klimov ◽  
Vitaliy Alekseevich Tseplyaev
Keyword(s):  
Friction Coefficient ◽  
Fruit Size ◽  
Spherical Body ◽  
Conveyor Belt ◽  
Damage Level ◽  
Rubber Cloth ◽  
Fruit Damage ◽  
Working Bodies

In this article, the authors discuss the results of experiments to determine the working bodies moving elements speeds ratio when harvesting watermelons or cabbage heads, having a shape close to a spherical body. It was revealed that the conveyor harvester for watermelons harvesting, equipped with an active roll-in machine, can jam the fruit between the conveyor belt and the roll-in belt, this leads to the fruit damage. To find the minimum allowable damage level (up to 5% according to the agrotechnical requirements), it is necessary that the roll-in tape is made of rubber cloth with a friction coefficient of fт = 0.48, with a ratio of speeds, the limits of change are from 1.0 to 1.3, fruit size is dmin= 15 cm, dmax = 30 cm.  

scholarly journals New Equation for Predicting Pipe Friction Coefficients Using the Statistical Based Entropy Concepts

Entropy ◽  
2021 ◽  
Vol 23 (5) ◽  
pp. 611
Author(s):  
Yeon-Woong Choe ◽  
Sang-Bo Sim ◽  
Yeon-Moon Choo
Keyword(s):  
Friction Coefficient ◽  
Accurate Determination ◽  
Mean Velocity ◽  
Friction Coefficients ◽  
Flow Discharge ◽  
Comparison Results ◽  
Flow Loss ◽  
Key Variables ◽  
New Equation

In general, this new equation is significant for designing and operating a pipeline to predict flow discharge. In order to predict the flow discharge, accurate determination of the flow loss due to pipe friction is very important. However, existing pipe friction coefficient equations have difficulties in obtaining key variables or those only applicable to pipes with specific conditions. Thus, this study develops a new equation for predicting pipe friction coefficients using statistically based entropy concepts, which are currently being used in various fields. The parameters in the proposed equation can be easily obtained and are easy to estimate. Existing formulas for calculating pipe friction coefficient requires the friction head loss and Reynolds number. Unlike existing formulas, the proposed equation only requires pipe specifications, entropy value and average velocity. The developed equation can predict the friction coefficient by using the well-known entropy, the mean velocity and the pipe specifications. The comparison results with the Nikuradse’s experimental data show that the R2 and RMSE values were 0.998 and 0.000366 in smooth pipe, and 0.979 to 0.994 or 0.000399 to 0.000436 in rough pipe, and the discrepancy ratio analysis results show that the accuracy of both results in smooth and rough pipes is very close to zero. The proposed equation will enable the easier estimation of flow rates.

Field trial of a pair production gauge for the on-line determination of ash in coal on a conveyor belt

1984 ◽  
Vol 35 (11) ◽  
pp. 1009-1021 ◽  
Author(s):  
M.J. Millen ◽  
B.D. Sowerby ◽  
P.T. Rafter ◽  
W.K. Ellis ◽  
V.L. Gravitis ◽  
...  
Keyword(s):  
Pair Production ◽  
Field Trial ◽  
Conveyor Belt ◽  
On Line

Determination of friction coefficient in journal bearings

2007 ◽  
Vol 28 (3) ◽  
pp. 973-977 ◽  
Author(s):  
Bekir Sadık Ünlü ◽  
Enver Atik
Keyword(s):  
Friction Coefficient ◽  
Journal Bearings

scholarly journals АНАЛІЗ КОЛИВАЛЬНИХ ПРОЦЕСІВ У ВІДЦЕНТРОВІЙ БАРАБАННІЙ ПРАЛЬНІЙ МАШИНІ

2019 ◽  
Vol 134 (3) ◽  
pp. 18-25
Author(s):  
О. Ю. Воляник ◽  
О. З. Гладчук
Keyword(s):  
Mathematical Model ◽  
Material Processing ◽  
Centrifugal Machine ◽  
Washing Machines ◽  
Working Bodies

Development  and  analysis  of  mathematical  model  of  oscillation  processes  that  occur during material processing in centrifugal drum washing machines, determination of absence conditions of contact deformations of working bodies and body of centrifugal machine.

scholarly journals Study of the nature of the dynamic coefficient of internal friction of grainmaterials

2019 ◽  
Vol 135 ◽  
pp. 01102
Author(s):  
Dmitriy Savenkov ◽  
Oleg Kirischiev ◽  
Ylia Kirischieva ◽  
Tatiana Tupolskikh ◽  
Tatiana Maltseva ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Internal Friction ◽  
Agricultural Production ◽  
Mechanical Characteristics ◽  
Dynamic Coefficient ◽  
Bulk Materials ◽  
Dynamic Coefficients ◽  
Internal Friction Coefficient ◽  
Physical And Mechanical Characteristics

The article highlights the issues related to the study of physical and mechanical characteristics of bulk materials, namely internal friction coefficients in static and dynamic modes. An innovative device of the carousel type for determining the frictional characteristics of bulk materials is described, which allows to implement the tasks of practical determination of dynamic coefficients of internal friction. Presented the program, methodology and results of research on the practical study of the internal friction coefficient of typical bulk products of agricultural production in the range of linear velocities of displacement of layers from 0 to 2.79 m/s, the reliability of which is not lower than 0.878.

Some Experimental and Analytical Results on Self-Excited Vibration of a Dynamic Sliding System in the Case of Stribeck Law for Friction Coefficient

2011 ◽  
Author(s):  
Julian Le Rouzic ◽  
Joel Perret-Liaudet ◽  
Alexandre Carbonelli ◽  
Alain Le Bot ◽  
Denis Mazuyer
Keyword(s):  
Friction Coefficient ◽  
Averaging Method ◽  
Conveyor Belt ◽  
Numerical Continuation ◽  
Test Rig ◽  
Single Degree Of Freedom ◽  
Excited Vibration ◽  
Friction Measurements ◽  
Non Linear System ◽  
Mass Spring

The principal aim of this paper is to deal with friction-induced self-excited vibrations in the context of Stribeck law for friction coefficient. More precisely, the theoretical dynamic system under study consists of a single-degree-of-freedom mass-spring-damper oscillator subjected to a velocity-dependent frictional force as it slides on a conveyor belt, following a Stribeck law. We have analyzed the local stability of the static equilibrium and described the created periodic cycle using the averaging method. Numerical continuation with Matcont software is also used for qualitative analysis of this non linear system. In order to validate the theoretical analysis, an original experimental device, the named Lug test rig developed in our laboratory, was employed. For a glass/elastomer contact lubricated with water, friction force and dynamic displacement have been measured. The appearance of the instabilities is explained in relation to the friction measurements.

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