Experimental investigation of the near-bit jet pump

2019 ◽  
Vol 6 (2) ◽  
pp. 35-40
Author(s):  
Ye. I. Kryzhanivskyi ◽  
D. O. Panevnyk
Keyword(s):  
Experimental Studies ◽  
Flow Distribution ◽  
Relative Pressure ◽  
Jet Pump ◽  
Mixed Flow ◽  
Theoretical Determination ◽  
Proposed Model ◽  
The Cost ◽  
The Mathematical Model

The nature of the flow distribution in the hydraulic system of the near-bit jet pump has been analyzed. The peculiarities of searching the pumping station operating point have been shown and the equation for determining hydraulic losses in the elements of the ejection system has been given. Based on experimental studies, an error in the theoretical determination of the relative pressure of a jet pump has been established when using a known and advanced model of its working process. In contrast to the known method, the proposed model provides for the determination of the hydraulic resistance of the chisel flushing system,which is located in the area of mixed flow at the cost of working, not mixed flow. Improving the mathematical model of the ejection system allows to reduce the error of theoretical determination of the relative pressure of the jet pump.

scholarly journals An Optimized Mathematical Model for Items Supplies Planning of a Logistic System

2016 ◽  
Vol 10 (10) ◽  
pp. 133
Author(s):  
Mohammad Ali Nasiri Khalili ◽  
Mostafa Kafaei Razavi ◽  
Morteza Kafaee Razavi
Keyword(s):  
Mathematical Model ◽  
Mixed Integer ◽  
Logistics System ◽  
Proposed Model ◽  
Multiple Objective Decision Making ◽  
System Requirements ◽  
Purchasing Logistics ◽  
The Cost ◽  
The Mathematical Model ◽  
First Time

Items supplies planning of a logistic system is one of the major issue in operations research. In this article the aim is to determine how much of each item per month from each supplier logistics system requirements must be provided. To do this, a novel multi objective mixed integer programming mathematical model is offered for the first time. Since in logistics system, delivery on time is very important, the first objective is minimization of time in delivery on time costs (including lack and maintenance costs) and the cost of purchasing logistics system. The second objective function is minimization of the transportation supplier costs. Solving the mathematical model shows how to use the Multiple Objective Decision Making (MODM) can provide the ensuring policy and transportation logistics needed items. This model is solved with CPLEX and computational results show the effectiveness of the proposed model.

Determination of Unknown Parameters of Photovoltaic Module Using Genetic Algorithm

2016 ◽  
Vol 4 (2) ◽  
pp. 271 ◽  
Author(s):  
I. M. Abdelqawee ◽  
Ayman Y. Yousef ◽  
Khaled M. Hasaneen ◽  
H. G. Hamed ◽  
Maged N. F. Nashed
Keyword(s):  
Genetic Algorithm ◽  
Operating Conditions ◽  
Maximum Power ◽  
Absolute Difference ◽  
Photovoltaic Module ◽  
Unknown Parameters ◽  
Pv Module ◽  
Proposed Model ◽  
The Mathematical Model

<p> In this paper, the unknown parameters of the photovoltaic (PV) module are determined using Genetic Algorithm (GA) method. This algorithm based on minimizing the absolute difference between the maximum power obtained from module datasheet and the maximum power obtained from the mathematical model of the PV module, at different operating conditions. This method does not need to initial values, so these parameters of the PV module are easily obtained with high accuracy. To validate the proposed method, the results obtained from it are compared with the experimental results obtained from the PV module datasheet for different operating conditions. The results obtained from the proposed model are found to be very close compared to the results given in the datasheet of the PV module.</p>

scholarly journals DETERMINATION OF THE HEAT DISTRIBUTION IN THE RAW COTTON PACKED IN THE COIL

2017 ◽  
Vol 3 ◽  
pp. 3-11
Author(s):  
Rahib Aqaqul Sailov ◽  
Fazil Ali Veliev ◽  
Qusni Kadir Kerimov
Keyword(s):  
Mathematical Model ◽  
Thermal Conductivity Coefficient ◽  
Experimental Studies ◽  
Heat Propagation ◽  
Heat Distribution ◽  
Spontaneous Heating ◽  
Saturated Form ◽  
The Mathematical Model ◽  
The Given

As a result of experimental studies, a special mathematical model of raw cotton is developed. The effect of density change on the thermal conductivity coefficient is determined. A nonlinear differential equation of heat propagation in coils is obtained. The dependence of the density of raw cotton on the coil height is determined experimentally. The heat flux is intense propagating from denser layers of raw cotton to less dense ones. In a saturated form, the effect of density changes on the propagation of heat is less than in the coils. Pocket spontaneous heating occurs locally with sharp boundaries. An expression is found, which is the general solution of the mathematical model of heat propagation in raw cotton in coils, on the basis of which a number of physical real models can be constructed. The model allows to preliminarily give an estimation of the likely picture of the temperature field in the given microvolumes of raw cotton.

Determination of the Optimal Number of Suppliers Considering the Risk: Emersun Company as a Case Study

2012 ◽  
Vol 433-440 ◽  
pp. 5873-5880 ◽  
Author(s):  
Nasim Mirahmadi ◽  
Esmaeel Saberi ◽  
Ebrahim Teimoury
Keyword(s):  
Supply Chain ◽  
Optimal Number ◽  
Development Cost ◽  
Supply Risk ◽  
Proposed Model ◽  
Management Area ◽  
The Cost ◽  
Tree Approach

Determining the number of suppliers chosen for cooperation in a supply chain is one of the most important problems in the supply chain management area. Regarding the fact that simultaneously decreasing the risk and cost is one of the most important objectives of every organization, besides the cost, the risk has also been introduced in the recent researches, as one of the most important criteria. In this paper, the decision tree approach is used for determining the optimal number of suppliers considering the supply risk and it has been tried to develop an applied method through expanding the cost criteria. The proposed model in this paper, therefore, contains any kind of cost ingredients such as cost of suppliers development, cost of suppliers management, cost of missing discount in volume due to increase in number of suppliers in supply base, and loss cost due to supply postponement from suppliers. This approach is implemented in Emersun Company.

INVESTIGATION OF TEMPERATURE OF BRAKE PADS WITH DIFFERENT EXTENT OF WEAR IN FRICTIONAL BRAKING

2020 ◽  
pp. 27-34
Author(s):  
P. Yu. Ivanov ◽  
◽  
A. M. Khudonogov ◽  
E. Yu. Dulskiy ◽  
A. A. Korsun ◽  
...  
Keyword(s):  
Experimental Studies ◽  
Flow Distribution ◽  
Rolling Stock ◽  
Finite Element Models ◽  
Brake Pads ◽  
Coefficient Increase ◽  
Engineering Drawings ◽  
Freight Car ◽  
Full Stop

The issue of railway rolling stock brake pad heating is examined under frictional braking within a freight car with unilateral push, equipped with castiron brake pads. Foreign and domestic experience of studies of heat cycles caused by friction has been examined, mechanism of heat release in the contact zone between a pad and wheel during braking with consideration of a heat flow distribution coefficient is described, mathematical modeling choice as a way to refine temperature measurements in the process of experimental studies is grounded, the results of estimated determination of the thermal flow affecting the pad in braking of a loaded freight car weighing 93 ts with 5 ts push upon the axle from 60 km/h to full stop are shown. Dynamics of thermal energy change emitting in frictional braking with consideration of wheel rotation decelerating speed and friction coefficient increase is emulated. Finite element models of pads with even wear, wedgelike wear and with no wear having geometry of relevant engineering drawings are described. The results of investigation of heating of brake pads with different wear types in the process of braking until full stop are given.

scholarly journals Numerical simulation of thermal-hydraulic processes in the riser chamber of installation for clinker production

2016 ◽  
Vol 37 (1) ◽  
pp. 127-142 ◽  
Author(s):  
Grzegorz Borsuk ◽  
Bolesław Dobrowolski ◽  
Grzegorz Nowosielski ◽  
Jacek Wydrych ◽  
Jerzy Duda
Keyword(s):  
Alternative Fuels ◽  
Experimental Studies ◽  
Operating Conditions ◽  
Raw Material ◽  
Cement Production ◽  
Numerical Studies ◽  
Stage Combustion ◽  
The Cost ◽  
The Mathematical Model ◽  
Clinker Production

AbstractClinker burning process has a decisive influence on energy consumption and the cost of cement production. A new problem is to use the process of decarbonization of alternative fuels from waste. These issues are particularly important in the introduction of a two-stage combustion of fuel in a rotary kiln without the typical reactor-decarbonizator. This work presents results of numerical studies on thermal-hydraulic phenomena in the riser chamber, which will be designed to burn fuel in the system where combustion air is supplied separately from the clinker cooler. The mathematical model is based on a combination of two methods of motion description: Euler description for the gas phase and Lagrange description for particles. Heat transfer between particles of raw material and gas was added to the numerical calculations. The main aim of the research was finding the correct fractional distribution of particles. For assumed particle distribution on the first stage of work, authors noted that all particles were carried away by the upper outlet to the preheater tower, what is not corresponding to the results of experimental studies. The obtained results of calculations can be the basis for further optimization of the design and operating conditions in the riser chamber with the implementation of the system.

scholarly journals Mixed Scheduling Model for Limited-Stop and Normal Bus Service with Fleet Size Constraint

Information ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 400
Author(s):  
Xiaohong Jiang ◽  
Jianxiao Ma
Keyword(s):  
Flow Distribution ◽  
Significant Saving ◽  
Fleet Size ◽  
Total Cost ◽  
Scheduling Model ◽  
Proposed Model ◽  
Depth Analysis ◽  
Bus Service ◽  
The Cost ◽  
The Relationship

Limited-stop service is useful to increase operation efficiency where the demand is unbalanced at different stops and unidirectional. A mixed scheduling model for limited-stop buses and normal buses is proposed considering the fleet size constraint. This model can optimize the total cost in terms of waiting time, in-vehicle time and operation cost by simultaneously adjusting the frequencies of limited-stop buses and normal buses. The feasibility and validity of the proposed model is shown by applying it to one bus route in the city of Zhenjiang, China. The results indicate that the mixed scheduling service can reduce the total cost and travel time compared with the single scheduling service in the case of unbalanced passenger flow distribution and fleet constraints. With a larger fleet, the mixed scheduling service is superior. There is an optimal fleet allocation that minimizes the cost for the system, and a significant saving could be attained by the mixed scheduling service. This study contributed to the depth analysis of the relationship among the influencing factors of mixed scheduling, such as fleet size constraint, departure interval and cost.

scholarly journals Mathematical modeling of area boundary of biaxial absolutely elastic states of wood

2020 ◽  
Vol 1 (1) ◽  
pp. 19-30
Author(s):  
S.` Holovata
Keyword(s):  
Orthotropic Materials ◽  
Algebraic Equations ◽  
Runge Kutta Method ◽  
Proposed Model ◽  
Pine Trees ◽  
Method Of Solution ◽  
Stress States ◽  
Best Parameter ◽  
The Mathematical Model

In the paper, the mathematical model for determination of the region boundary of biaxial elastic states of orthotropic materials is synthesized and the system of nonlinear algebraic equations for identification of its parameters is obtained. Using the continuous method of solution continuation concerning the best parameter and the Runge-Kutta method, the demarcation curves of absolutely elastic and non-elastic deformation regions for pine trees are depicted. The analysis of the obtained curves is carried out and on its base, it is shown that the proposed model makes possible to determine and substantiate the ultimate stress states of materials whose the asymmetry coefficients of the boundaries of proportionality in some anisotropy directions are greater, and in others less than one.

THE METHOD OF DETERMINING THE PUNCHING ACTION OF THE READY-MADE DAMAGE ELEMENT OF FRAGMENTATION OF HIGH-EXPLOSIVE WARHEAD

2019 ◽  
Vol 1 (12) ◽  
pp. 41-47
Author(s):  
O. Obukhov ◽  
S. Usenko
Keyword(s):  
High Explosive ◽  
Experimental Studies ◽  
Limited Range ◽  
Software Complex ◽  
Penetration Ability ◽  
The Subject ◽  
Cruise Missiles ◽  
The Cost ◽  
The Impact

The subject of this article is the development of a method for determining the penetration capacity of ready-made elements of damage to a fragmentation and high-explosive warhead. The analysis of the existing methods of determining the penetration capacity of the damage elements indicates their inconsistency with the modern requirements for determining the power of means of destruction of combat parts of missiles, tactical and cruise missiles and aircraft bombs. Existing techniques that were proposed in the late 19th and early 20th centuries are based on the systematization of empirical research and are outdated and have a limited range of applications. Since they do not take into account the zone of contact interacting between the element of the impact and the obstacle and the critical angle of approach, which will determine the ricochet conditions. The article presents the results of the calculated determination of the penetration capacity of the ready-made damage element, taking into account the contact surface of the interaction of the damage element with the obstacle, which are obtained as a result of the calculation modelling in the Ansys Autodyn software complex. Ways to determine the penetration capacity of ready-made destruction elements of fragmentation and high-explosive warhead, taking into account their true geometric shape and excess kinetic energy are proposed in the article. The proposed technique can be used to create the penetration nomograms of the elements of the lesion. The application of computational modeling of the determination of nonograms of penetration ability will allow to abandon a large number of experimental studies with real undermining of the warhead, thereby reducing the cost and speeding up the process of creating, refining and adopting the newest samples of defeat equipment.

scholarly journals A simplified formula for determination of relative pressure in the precision forging of spur gears

2021 ◽  
Vol 9 (2) ◽  
Author(s):  
Omer Eyercioglu ◽  
◽  
Necip F. Yılmaz F. Yılmaz ◽  
Keyword(s):  
Experimental Studies ◽  
Relative Pressure ◽  
Spur Gears ◽  
Upper Bound Method ◽  
Complete Filling ◽  
Precision Forging ◽  
Corner Filling ◽  
Suggested Formula ◽  
Simplified Formula

In this study, the relative forging pressures of spur gears were evaluated. The precision forging of spur gears was analyzed by using the upper bound method considering corner filling and bulging effect. Numerical and experimental studies were performed to investigate the effects of various parameters, such as the number of teeth, modules, facewidth, bore diameter, and friction factor on the relative forging pressure of spur gears. The results were compared with the previous studies and a simplified formula was suggested to predict the relative pressure of precision forging of spur gears. The predicted relative forging pressures obtained by the suggested formula are shown much closer to the experimental results for the complete filling of the die cavity.

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